[ { "id": "https://authors.library.caltech.edu/records/8he0p-sfb54", "eprint_id": 97776, "eprint_status": "archive", "datestamp": "2023-08-19 17:03:42", "lastmod": "2023-10-18 16:43:03", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Newhouse-P-F", "name": { "family": "Newhouse", "given": "Paul" }, "orcid": "0000-0003-2032-3010" }, { "id": "Guevarra-D-W", "name": { "family": "Guevarra", "given": "Dan" }, "orcid": "0000-0002-9592-3195" }, { "id": "Umehara-Mitsutaro", "name": { "family": "Umehara", "given": "Mitsu" }, "orcid": "0000-0001-8665-0028" }, { "id": "Boyd-D-A", "name": { "family": "Boyd", "given": "David" } }, { "id": "Zhou-Lan", "name": { "family": "Zhou", "given": "Lan" }, "orcid": "0000-0002-7052-266X" }, { "id": "Cooper-J-K", "name": { "family": "Cooper", "given": "Jason" }, "orcid": "0000-0002-7953-4229" }, { "id": "Haber-J-A", "name": { "family": "Haber", "given": "Joel" }, "orcid": "0000-0001-7847-5506" }, { "id": "Gregoire-J-M", "name": { "family": "Gregoire", "given": "John M." }, "orcid": "0000-0002-2863-5265" } ] }, "title": "Multi-modal optimization of bismuth vanadate photoanodes via combinatorial alloying and hydrogen processing", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2019 American Chemical Society.", "abstract": "Alloying transition metals, such as Mo, into BiVO_4 has emerged as the primary mechanism for improving carrier transport in this photoanode for solar fuels prodn. The present work establishes the generality of improving photoelectrochem. performance through co-alloying with a transition metal electron donor and a structure-modulating rare earth. Further improvement for all such alloys is obtained by annealing the oxide materials in H_2, ultimately producing photoanodes with above 3 mA cm-2 photocurrent d. under AM 1.5G illumination, in the top tier of compact BiVO_4 films.", "date": "2019-08", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20190812-125247272", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190812-125247272", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "JCAP" } ] }, "pub_year": "2019", "author_list": "Newhouse, Paul; Guevarra, Dan; et el." }, { "id": "https://authors.library.caltech.edu/records/j37w6-ywk24", "eprint_id": 97772, "eprint_status": "archive", "datestamp": "2023-08-19 17:03:23", "lastmod": "2023-10-18 16:42:42", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Haber-J-A", "name": { "family": "Haber", "given": "Joel" }, "orcid": "0000-0001-7847-5506" }, { "id": "Stein-H-S", "name": { "family": "Stein", "given": "Helge S." }, "orcid": "0000-0002-3461-0232" }, { "id": "Guevarra-D-W", "name": { "family": "Guevarra", "given": "Dan" }, "orcid": "0000-0002-9592-3195" }, { "id": "Shinde-A", "name": { "family": "Shinde", "given": "Aniketa" }, "orcid": "0000-0003-2386-3848" }, { "id": "Jones-R-J-R", "name": { "family": "Jones", "given": "Ryan J. R." }, "orcid": "0000-0002-4629-3115" }, { "id": "Gregoire-J-M", "name": { "family": "Gregoire", "given": "John M." }, "orcid": "0000-0002-2863-5265" } ] }, "title": "Functional mapping reveals mechanistic clusters for OER catalysis across (Cu-Mn-Ta-Co-Sn-Fe)Ox composition and pH space", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2019 American Chemical Society.", "abstract": "Identification of stable electrocatalysts for the oxygen evolution reaction (OER) remains a primary challenge in materials for energy. The pH-dependent activity is known for very few catalysts, prompting our exploration of a broad range of catalysts using high throughput expts. and data science. This approach enables the largest screening of OER activity and operational stability to date, as illustrated through investigation of the (Cu-Mn-Ta-Co-Sn-Fe)O_x compn. space as 15 unique quaternary compn. spaces. In total 2121 compns. are tested between pH 3 and 13, creating an extensive dataset whose interpretation requires development and application of data science to provide insights that are both beyond the std. compn.-activity relationships and beyond human interpretation due to the dimensionality of the dataset. Three distinct classes of OER catalysts are identified with respect to pH-dependent activity and stability. The large-scale screening reveals a new class of Co-rich OER catalysts that can be compositionally tailored to a specified pH and perform on par with state-of-the-art acid OER catalysts.", "date": "2019-08", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20190812-111645069", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190812-111645069", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "JCAP" } ] }, "pub_year": "2019", "author_list": "Haber, Joel; Stein, Helge S.; et el." }, { "id": "https://authors.library.caltech.edu/records/spsjd-k5177", "eprint_id": 97774, "eprint_status": "archive", "datestamp": "2023-08-19 17:03:36", "lastmod": "2023-10-18 16:42:53", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Labinger-J-A", "name": { "family": "Labinger", "given": "Jay Alan" }, "orcid": "0000-0002-1942-9232" } ] }, "title": "History (and pre-history) of the discovery and chemistry of the noble gases", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2019 American Chemical Society.", "abstract": "Cavendish's 1783 measurements showing that around 1/120 of the vol. of air appeared to be neither nitrogen or oxygen, along with Lockyer's 1868 observation of a solar spectral line that corresponded to no known element on earth, were early but unrecognized hints of elements that could not be accommodated in Mendeleev's Periodic Table. Following a series of painstaking expts., in 1895 Lord Rayleigh and William Ramsay announced the isolation of a new element, which they called argon. Their claim was widely challenged - not least by Mendeleev himself - with alternate interpretations, particularly that the substance was actually N_3, an allotrope of nitrogen analogous to ozone. Within the next few years, though, Ramsay demonstrated the existence of four more such inert gases: He, isolated from minerals and shown to exhibit the mystery solar spectral line; and Ne, Kr, and Xe, by cryogenic fractionation of air. Ramsay inserted a place in the Periodic Table for this new group in 1896; Frederick Soddy added Rn in 1903; and Ramsay received the chem. Nobel Prize in 1904. Attempts to induce reactivity began almost immediately, but with no (reproducible) success. Friedrich Paneth proclaimed in 1924 that the unreactivity of the noble gases \"belongs to the surest of exptl. results,\" while others - notably Linus Pauling - insisted that they should form compds. under the right conditions. In 1933, at Pauling's instigation, Caltech chemist Don Yost carried out an unsuccessful assault on xenon's inertness, which was finally overcome three decades later. Neil Bartlett's discovery of \"Xe+[PtF_6]-\" was followed quickly by extensive demonstrations of chem. reactivity, along with considerable speculation on the reasons for Yost's failure. I will very briefly summarize the former, and offer my own interpretation of the latter.", "date": "2019-08", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20190812-112253672", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20190812-112253672", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "JCAP" } ] }, "pub_year": "2019", "author_list": "Labinger, Jay Alan" }, { "id": "https://authors.library.caltech.edu/records/mkqgn-jga35", "eprint_id": 85773, "eprint_status": "archive", "datestamp": "2023-08-19 08:02:46", "lastmod": "2023-10-18 18:46:41", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gregoire-J-M", "name": { "family": "Gregoire", "given": "John" }, "orcid": "0000-0002-2863-5265" } ] }, "title": "Accelerated experimental materials discovery through integration with theory and artificial intelligence", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2018 American Chemical Society.", "abstract": "Solar photochem. is a promising energy technol. limited by the performance and compatibility of its component\nmaterials. A variety of approaches for discovering solar fuels materials have been and continue to be\ndeployed, with photoactive components proving to be particularly difficult to identify due to their need to\nsimultaneously exhibit a broad range of chem. and phys. properties. The development of high throughput\nscreening techniques in the Joint Center for Artificial Photosynthesis has opened new avenues for materials\ndiscovery with unique challenges and opportunities. Most notably, rapid synthesis and screening enables\nevaluation of candidate materials proposed by high throughput computational screening, and some expts.\nproduce datasets that are too large and complex to be interpreted by std. techniques or even expert materials\nscientists, motivating the development of artificial intelligence algorithms. Integration of the resp.\ncomputational techniques with expts. accelerates both materials discovery and understanding of known\nmaterials, creating new paradigms for conducting materials research and developing multi-functional\nmaterials.", "date": "2018-03", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20180412-075704210", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180412-075704210", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "JCAP" } ] }, "pub_year": "2018", "author_list": "Gregoire, John" }, { "id": "https://authors.library.caltech.edu/records/yq8v0-wr360", "eprint_id": 85853, "eprint_status": "archive", "datestamp": "2023-08-19 08:05:45", "lastmod": "2023-10-18 18:52:57", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Lewis-N-S", "name": { "family": "Lewis", "given": "Nathan S." }, "orcid": "0000-0001-5245-0538" } ] }, "title": "Sunlight-driven hydrogen formation by membrane-supported photoelectrochemical water splitting", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2018 American Chemical Society.", "abstract": "We are developing an artificial photosynthetic system that will utilize sunlight and water as inputs and will produce hydrogen\nand oxygen as outputs using a modular, parallel development approach in which the three distinct primary components-the\nphotoanode, the photocathode, and the product-sepg. but ion-conducting membrane-are fabricated and optimized sep. before\nassembly into a water-splitting system. The design principles incorporate two sep., photosensitive semiconductor/liq. junctions\nthat will collectively generate the 1.7-1.9 Vat open circuit to support both the oxidn. of H2_O (or OH-) and the redn. of H+ (or\nH_2O). The photoanode and photocathode will consist of rod-like semiconductor components, with attached heterogeneous multielectron\ntransfer catalysts, needed to drive the oxidn. or redn. reactions at low overpotentials. The high aspect-ratio\nsemiconductor rod electrode architecture allows for the use of low cost, earth abundant materials without sacrificing energy\nconversion efficiency due to orthogonalization of light absorption and charge-carrier collection. Addnl., the high surface-area\ndesign of the rod-based semiconductor array electrode inherently lowers the flux of charge carriers over the rod array surface\nrelative to the projected geometric surface of the photoelectrode, lowering the photocurrent d. at the solid/liq. junction and\nthereby relaxing demands on the activity (and cost) of any electrocatalysts. Flexible composite polymer film will allow for\nelectron and ion conduction between the photoanode and photocathode while simultaneously preventing mixing of the gaseous\nproducts. Sep. polymeric materials will be used to make elec. contact between the anode and cathode and also provide\nstructural support. Interspersed patches of an ion conducting polymer will maintain charge balance between the two half-cells.\nThe modularity design approach allows each piece to be independently modified, tested, and improved, as future advances in\nsemiconductor, polymeric, and catalytic materials are made. This work will demonstrate a feasible and functional prototype and\nblueprint for an artificial photosynthetic system, composed of inexpensive, earth-abundant materials while simultaneously\nefficient, durable, manufacturably scalable, and readily upgradeable.", "date": "2018-03", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20180413-153323263", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180413-153323263", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "JCAP" } ] }, "pub_year": "2018", "author_list": "Lewis, Nathan S." }, { "id": "https://authors.library.caltech.edu/records/wkd0v-qp174", "eprint_id": 85800, "eprint_status": "archive", "datestamp": "2023-08-19 08:03:50", "lastmod": "2023-10-18 18:48:33", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Haber-J-A", "name": { "family": "Haber", "given": "Joel" }, "orcid": "0000-0001-7847-5506" }, { "id": "Guevarra-D-W", "name": { "family": "Guevarra", "given": "Dan" }, "orcid": "0000-0002-9592-3195" }, { "id": "Jones-R-J-R", "name": { "family": "Jones", "given": "R. J. R." }, "orcid": "0000-0002-4629-3115" }, { "id": "Kan-Kevin", "name": { "family": "Kan", "given": "Kevin" } }, { "id": "Gregoire-J-M", "name": { "family": "Gregoire", "given": "John" }, "orcid": "0000-0002-2863-5265" } ] }, "title": "High throughput, multi-pH evaluation of earth-abundant pseudo-quaternary metal oxide catalysts for the oxygen evolution reaction", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2018 American Chemical Society.", "abstract": "The development of efficient, stable photoanodes for solar fuels generators requires integration of a light absorbing\nsemiconductor with an efficient oxygen evolution reaction catalyst. However, the abs. and relative performance of different\nOER catalyst compns. vary with electrolyte pH. The operational conditions for the solar fuel generators is often dictated by the\npH stability range of the light absorber, not the conditions optimal for OER catalysis. We are evaluating the activity and\nstability against corrosion of dozens of comprehensive multi-metal oxide compn. spaces from pH 1-13 using high\nthroughput electrochem. methods. This talk will describe these methods and characteristic results.", "date": "2018-03", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20180412-160639482", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180412-160639482", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "JCAP" } ] }, "pub_year": "2018", "author_list": "Haber, Joel; Guevarra, Dan; et el." }, { "id": "https://authors.library.caltech.edu/records/cg3xa-ydw29", "eprint_id": 85799, "eprint_status": "archive", "datestamp": "2023-08-19 08:03:43", "lastmod": "2023-10-18 18:48:30", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Haber-Joel-A", "name": { "family": "Haber", "given": "Joel" }, "orcid": "0000-0001-7847-5506" }, { "id": "Guevarra-Dan-W", "name": { "family": "Guevarra", "given": "Dan" }, "orcid": "0000-0002-9592-3195" }, { "id": "Shinde-Aniketa-A", "name": { "family": "Shinde", "given": "Aniketa" }, "orcid": "0000-0003-2386-3848" }, { "id": "Zhou-Lan", "name": { "family": "Zhou", "given": "Lan" }, "orcid": "0000-0002-7052-266X" }, { "id": "Toma-Francesca-M", "name": { "family": "Toma", "given": "Francesca" }, "orcid": "0000-0003-2332-0798" }, { "id": "Gregoire-J-M", "name": { "family": "Gregoire", "given": "John" }, "orcid": "0000-0002-2863-5265" } ] }, "title": "Development of solar fuels photoanodes through combinatorial integration of multifunctional Fe-Ce oxide coatings on BiVO4 as a function of coating composition, loading, and electrolyte", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2018 American Chemical Society.", "abstract": "The development of an efficient, stable photoanode to provide protons and electrons to the (photo)cathode remains a primary\nmaterials challenge in the establishment of a scalable technol. for artificial photosynthesis. The typical photoanode architecture\nconsists of a semiconductor light absorber coated with a metal oxide that serves a combination of functions, including corrosion\nprotection, electrocatalysis, light trapping, hole transport, and elimination of deleterious surface recombination sites. To\nprovide a more efficient exploration of metal oxide coatings for a given light absorber, we introduce a high throughput\nmethodol. wherein a uniform BiVO4 library is coated with multi-metal oxide coatings. This presentation will focus on the\nvariation in performance and photo-response of integrated photoanodes consisting of BiVO4 coated with a sputter deposited\nFe-Ce oxide film as a function of compn. and loading. Parallel photoanode libraries were prepd. and evaluated at pH 13 and pH 9.", "date": "2018-03", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20180412-155950683", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180412-155950683", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "JCAP" } ] }, "pub_year": "2018", "author_list": "Haber, Joel; Guevarra, Dan; et el." }, { "id": "https://authors.library.caltech.edu/records/wk4dt-19q16", "eprint_id": 86181, "eprint_status": "archive", "datestamp": "2023-08-19 04:31:15", "lastmod": "2023-10-18 19:20:18", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Liu-Guiji", "name": { "family": "Liu", "given": "Guiji" }, "orcid": "0000-0002-3943-4119" }, { "id": "Eichhorn-Johanna", "name": { "family": "Eichhorn", "given": "Johanna" }, "orcid": "0000-0003-2413-6079" }, { "id": "Haber-Joel-A", "name": { "family": "Haber", "given": "Joel" }, "orcid": "0000-0001-7847-5506" }, { "id": "Gregoire-J-M", "name": { "family": "Gregoire", "given": "John" }, "orcid": "0000-0002-2863-5265" }, { "id": "Sharp-Ian-D", "name": { "family": "Sharp", "given": "Ian" }, "orcid": "0000-0001-5238-7487" }, { "id": "Toma-Francesca-M", "name": { "family": "Toma", "given": "Francesca Maria" }, "orcid": "0000-0003-2332-0798" } ] }, "title": "Optical, morphological, and electrochemical multimodal characterization for integrated BiVO4 photoanodes", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2017 American Chemical Society.", "abstract": "Photoelectrochem. water splitting is a promising route for efficient conversion of solar energy to chem. fuel.\nHowever, the development of an efficient photoanode remains the primary materials challenge in the\nestablishment of a scalable technol. for solar water splitting. The typical photoanode architecture consists of a\nsemiconductor light absorber coated with a metal oxide that serves a combination of functions, including\ncorrosion protection, electrocatalysis, light trapping, hole transport, and elimination of deleterious recombination\nsites. In addn., the functional behavior of photocatalytic systems strongly depends on the presence of structural\ndefects and heterogeneity over different length scales. Indeed, charge trapping at interfaces and/or (photo)\ncorrosion processes can affect catalytic performance and selectivity. Here, we show an approach to the\ndiscovery integrated photoanodes based on bismuth vanadate light absorber. Among different photoelectrode\nmaterials, BiVO is one of the most actively investigated oxide semiconductors due to its moderate bandgap,\nfavorable conduction band position, and relatively long photocarrier lifetimes. By use of in situ optical\nspectroscopy and comparisons between the metal oxide coatings and their extrinsic optical and electrocatalytic\nproperties, we present a suite of data-driven discoveries, including the scale-up of compn. regions which form\noptimal interfaces with BiVO . We use photoconductive at. force microscopy to correlate local surface morphol.\nwith generated photocurrent maps at individual grain facets in BiVO . The photocurrent maps resolve the\ncontributions from individual grains with nanometer spatial resoln. This careful anal. allows us to identify charge\ntransfer and loss mechanism at the nanoscale that ultimately contribute to det. the macroscale properties of the\nmaterial.", "date": "2017-08", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20180502-083014371", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20180502-083014371", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "JCAP" } ] }, "pub_year": "2017", "author_list": "Liu, Guiji; Eichhorn, Johanna; et el." }, { "id": "https://authors.library.caltech.edu/records/d84gd-nny97", "eprint_id": 77230, "eprint_status": "archive", "datestamp": "2023-08-19 02:25:04", "lastmod": "2023-10-25 21:59:52", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Haber-Joel-A", "name": { "family": "Haber", "given": "Joel" }, "orcid": "0000-0001-7847-5506" }, { "id": "Guevarra-Dan-W", "name": { "family": "Guevarra", "given": "Dan" }, "orcid": "0000-0002-9592-3195" }, { "id": "Shinde-Aniketa-A", "name": { "family": "Shinde", "given": "Aniketa" }, "orcid": "0000-0003-2386-3848" }, { "id": "Zhou-Lan", "name": { "family": "Zhou", "given": "Lan" }, "orcid": "0000-0002-7052-266X" }, { "id": "Li-Guo", "name": { "family": "Li", "given": "Guo" } }, { "id": "Liu-Guiji", "name": { "family": "Liu", "given": "Guiji" }, "orcid": "0000-0002-3943-4119" }, { "id": "Sharp-Ian-D", "name": { "family": "Sharp", "given": "Ian" }, "orcid": "0000-0001-5238-7487" }, { "id": "Neaton-Jeffrey-B", "name": { "family": "Neaton", "given": "Jeffrey B." }, "orcid": "0000-0001-7585-6135" }, { "id": "Toma-Francesca-M", "name": { "family": "Toma", "given": "Francesca M." }, "orcid": "0000-0003-2332-0798" }, { "id": "Gregoire-J-M", "name": { "family": "Gregoire", "given": "John" }, "orcid": "0000-0002-2863-5265" } ] }, "title": "Development of solar fuels photoanodes through combinatorial integration of Ni- La-Co-Ce oxide and Ni-Fe-Co-Ce oxide catalysts on BiVO\u2084", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2017 American Chemical Society.", "abstract": "The development of an efficient, stable photoanode provide protons and electrons to the (photo)cathode remains a primary materials challenge in the establishment of a scalable technol. for solar fuels generation. The typical photoanode architecture consists of a semiconductor light absorber coated with a metal oxide that serves a combination of functions, including corrosion protection, electrocatalysis, light trapping, hole transport, and elimination of deleterious recombination sites. To provide a more efficient exploration of metal oxide coatings for a given light absorber, we introduce a high throughput methodol. wherein a uniform BIVO\u2084 library is coated with 858 unique metal oxides covering a range of metal oxide loadings and the full NI-La-Co-Ce oxide or Ni-Fe-Co-Ce oxide psuedo-quaternary compn. spaces. Photoelectrochem. characterization of each photoanode reveals that approx. one third of the coatings lower the photoanode performance while select combinations of metal oxide compn. and loading provide up to a 14-fold increase in the max. photoelectrochem. power generation for oxygen evolution in pH 13 electrolyte. Particular Ce-rich coatings also exhibit an anti-reflection effect that further amplifies the performance, yielding a 20-fold enhancement in power conversion efficiency compared to bare BiVO\u2084. By use of in situ optical spectroscopy and comparisons between the metal oxide coatings and their extrinsic optical and electrocatalytic properties, we present a suite of data-driven discoveries, including compn. regions which form optimal interfaces with BiVO\u2084 and photoanodes that are suitable for integration with a photocathode due to their excellent power conversion and solar transmission efficiencies. The initial high throughput discoveries were extended and validated through follow-up high throughput investigations and conventional photoelectrochem. measurements. The high throughput experimentation and informatics provides a powerful platform for both identifying the pertinent interfaces for further study and discovering high performance photoanodes for incorporation into efficient water splitting devices.", "date": "2017-04", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20170505-132757377", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170505-132757377", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "JCAP" } ] }, "pub_year": "2017", "author_list": "Haber, Joel; Guevarra, Dan; et el." }, { "id": "https://authors.library.caltech.edu/records/h8vp9-sjh13", "eprint_id": 77258, "eprint_status": "archive", "datestamp": "2023-08-19 02:25:26", "lastmod": "2023-10-25 22:01:31", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Newhouse-P-F", "name": { "family": "Newhouse", "given": "Paul" }, "orcid": "0000-0003-2032-3010" }, { "id": "Boyd-D-A", "name": { "family": "Boyd", "given": "David" } }, { "id": "Shinde-A", "name": { "family": "Shinde", "given": "Aniketa" }, "orcid": "0000-0003-2386-3848" }, { "id": "Guevarra-D-W", "name": { "family": "Guevarra", "given": "Dan" }, "orcid": "0000-0002-9592-3195" }, { "id": "Zhou-Lan", "name": { "family": "Zhou", "given": "Lan" }, "orcid": "0000-0002-7052-266X" }, { "id": "Soedarmadji-E", "name": { "family": "Soedarmadji", "given": "Edwin" } }, { "id": "Li-Guo", "name": { "family": "Li", "given": "Guo" } }, { "id": "Neaton-J-B", "name": { "family": "Neaton", "given": "Jeffrey B." }, "orcid": "0000-0001-7585-6135" }, { "id": "Gregoire-J-M", "name": { "family": "Gregoire", "given": "John M." }, "orcid": "0000-0002-2863-5265" } ] }, "title": "Solar fuels photoanodes prepared by inkjet printing of copper vanadates", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2017 American Chemical Society.", "abstract": "Widespread deployment of solar fuel generators requires the development of efficient and scalable functional materials, esp. for photoelectrocatalysis of the oxygen evolution reaction. Metal oxides comprise the most promising class of photoanode materials, but no known material meets the demanding photoelectrochem. requirements. Copper vanadates have recently been identified as a promising class of photoanode materials with several phases exhibiting an indirect band gap near 2 eV and stable photoelectrocatalysis of the oxygen evolution reaction in a pH 9.2 electrolyte. By employing combinatorial inkjet\nprinting of metal precursors and applying both caldnation and rapid thermal processing, we characterize the phase behavior of the entire CuO-V2O5 compn. space for different thermal treatments via automated anal. of approx. 100 000 Raman spectra acquired using a novel Raman Imaging technique. These results enable the establishment of structure-property relationships for optical absorption and photoelectrochem. properties, revealing that highly active photoelectrocatalysts contg. alpha-Cu2V2O7 or alpha-CuV2O6 can be prepd. using scalable soln. processing techniques. An addnl. discovery results from the formation of an\noff-stoichiometric beta-Cu2V2O7 material that exhibits high photoelectroaclivity in the presence of a ferri/ferrocyanide redox couple with excellent stability in a pH 13 electrolyte, demonstrating that copper vanadates may be viable photoanodes in strong alk. electrolytes.", "date": "2017-04", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20170508-105609944", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170508-105609944", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "collection": "CaltechAUTHORS", "local_group": { "items": [ { "id": "JCAP", "value": "JCAP" } ] }, "pub_year": "2017", "author_list": "Newhouse, Paul; Boyd, David; et el." }, { "id": "https://authors.library.caltech.edu/records/8wekh-80349", "eprint_id": 77299, "eprint_status": "archive", "datestamp": "2023-08-19 02:25:55", "lastmod": "2023-10-25 22:03:36", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Gregoire-J-M", "name": { "family": "Gregoire", "given": "John" }, "orcid": "0000-0002-2863-5265" } ] }, "title": "High throughput discovery of solar fuels photoanodes", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2017 American Chemical Society.", "abstract": "The High Throughput Experimentation (HTE) project of the Joint Center for Artificial Photosynthesis performs accelerated discovery of earth-abundant photoelectrocatalysts and other solar fuels materials. The HTE materials discovery framework integrates experimentation with materials theory and has recently been deployed for the identification of several new classes of metal oxide photoelectrocatalysts for the oxygen\nevolution reaction. Through compilation and inspection of these discoveries, relationships among compn., structure, electronic structure, stability, photoactivity, band gap energy, etc. are being identified, providing a deeper understanding of the known materials and enabling the design of new photoanode materials. In addn. to introducing the materials discovery pipeline, I will survey our recent discoveries and highlight the most pertinent lessons learned for developing metal oxide photoanodes.", "date": "2017-04", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20170509-103759935", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20170509-103759935", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "collection": "CaltechAUTHORS", "local_group": { "items": [ { "id": "JCAP", "value": "JCAP" } ] }, "pub_year": "2017", "author_list": "Gregoire, John" }, { "id": "https://authors.library.caltech.edu/records/cbcq1-11z27", "eprint_id": 68607, "eprint_status": "archive", "datestamp": "2023-08-20 11:50:21", "lastmod": "2023-10-19 22:21:56", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Haber-Joel-A", "name": { "family": "Haber", "given": "Joel" }, "orcid": "0000-0001-7847-5506" }, { "id": "Guevarra-Dan-W", "name": { "family": "Guevarra", "given": "Dan" }, "orcid": "0000-0002-9592-3195" }, { "id": "Shinde-Aniketa-A", "name": { "family": "Shinde", "given": "Aniketa" }, "orcid": "0000-0003-2386-3848" }, { "id": "Zhou-Lan", "name": { "family": "Zhou", "given": "Lan" }, "orcid": "0000-0002-7052-266X" }, { "id": "Liu-Guiji", "name": { "family": "Liu", "given": "Guiji" }, "orcid": "0000-0002-3943-4119" }, { "id": "Sharp-Ian-D", "name": { "family": "Sharp", "given": "Ian" }, "orcid": "0000-0001-5238-7487" }, { "id": "Toma-Francesca-M", "name": { "family": "Toma", "given": "Francesca" }, "orcid": "0000-0003-2332-0798" }, { "id": "Gregoire-J-M", "name": { "family": "Gregoire", "given": "John" }, "orcid": "0000-0002-2863-5265" } ] }, "title": "Development of solar fuels photoanodes through combinatorial integration of Ni-La-Co-Ce oxide and Ni-Fe-Co-Ce oxide catalysts on BiVO\u2084", "ispublished": "unpub", "full_text_status": "public", "note": "\u00a9 2016 ECS - The Electrochemical Society.\n\n
Published - Haber_2016pGC+E-14.pdf
", "abstract": "The development of an efficient, stable photoanode to provide protons and electrons to the (photo)cathode remains a primary materials challenge in the establishment of a scalable technol. for solar fuels generation. The typical photoanode architecture consists of a semiconductor light absorber coated with a metal oxide that serves a combination of functions, including corrosion protection, electrocatalysis, light trapping, hole transport, and elimination of deleterious recombination sites. To provide a more efficient exploration of metal oxide coatings for a given light absorber, we introduce a high throughput methodol. wherein a uniform BiVO\u2084 library is coated with 858 unique metal oxides covering a range of metal oxide loadings and the full Ni-La-Co-Ce oxide or Ni-Fe-Co-Ce oxide psuedo-quaternary compn. spaces. Photoelectrochem. characterization of each photoanode reveals that approx. one third of the coatings lower the photoanode performance while select combinations of metal oxide compn. and loading provide up to a 14-fold increase in the max. photoelectrochem. power generation for oxygen evolution in pH 13 electrolyte. Particular Ce-rich coatings also exhibit an anti-reflection effect that further amplifies the performance, yielding a 20-fold enhancement in power conversion efficiency compared to bare BiVO\u2084. By use of in situ optical spectroscopy and comparisons between the metal oxide coatings and their extrinsic optical and electrocatalytic properties, we present a suite of data-driven discoveries, including compn. regions which form optimal interfaces with BiVO\u2084 and photoanodes that are suitable for integration with a photocathode due to their excellent power conversion and solar transmission efficiencies. The initial high throughput discoveries were extended and validated through follow-up high throughput investigations and conventional photoelectrochem. measurements. The high throughput experimentation and informatics provides a powerful platform for both identifying the pertinent interfaces for further study and discovering high performance photoanodes for incorporation into efficient water splitting devices.", "date": "2016-06", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20160622-150845222", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160622-150845222", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "JCAP" } ] }, "primary_object": { "basename": "Haber_2016pGC+E-14.pdf", "url": "https://authors.library.caltech.edu/records/cbcq1-11z27/files/Haber_2016pGC+E-14.pdf" }, "pub_year": "2016", "author_list": "Haber, Joel; Guevarra, Dan; et el." }, { "id": "https://authors.library.caltech.edu/records/tpzrx-k8423", "eprint_id": 65796, "eprint_status": "archive", "datestamp": "2023-08-20 10:33:35", "lastmod": "2023-10-18 16:48:30", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Goddard-W-A-III", "name": { "family": "Goddard", "given": "William" }, "orcid": "0000-0003-0097-5716" }, { "id": "Cheng-Tao", "name": { "family": "Cheng", "given": "Tao" }, "orcid": "0000-0003-4830-177X" }, { "id": "Xiao-Hai", "name": { "family": "Xiao", "given": "Hai" }, "orcid": "0000-0001-9399-1584" } ] }, "title": "Detailed reaction mechanisms for oxygen-reduction and CO_2-reduction reactions at electrode surfaces", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2016 American Chemical Society.", "abstract": "We will report here first principles predictions (d. functional theory with periodic boundary conditions) of the\nstructures, mechanisms, and acivation barriers for the redn. of O2 to H2O and the redn. of CO to orgs. on\nelectrode surfaces. These calcns. include full explicit solvent, pH, and, electrode potentials and use\nmetadynamics to obtain free energy barreires.", "date": "2016-03", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20160331-093542250", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20160331-093542250", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "JCAP" } ] }, "pub_year": "2016", "author_list": "Goddard, William; Cheng, Tao; et el." }, { "id": "https://authors.library.caltech.edu/records/jb1vs-xh157", "eprint_id": 45209, "eprint_status": "archive", "datestamp": "2023-08-19 23:40:18", "lastmod": "2023-10-26 17:52:05", "type": "conference_item", "metadata_visibility": "show", "creators": { "items": [ { "id": "Haber-J-A", "name": { "family": "Haber", "given": "Joel A." }, "orcid": "0000-0001-7847-5506" }, { "id": "Jung-Suho", "name": { "family": "Jung", "given": "Suho" }, "orcid": "0000-0002-8119-3902" }, { "id": "Guevarra-D-W", "name": { "family": "Guevarra", "given": "Dan" }, "orcid": "0000-0002-9592-3195" }, { "id": "Xiang-Chengxiang", "name": { "family": "Xiang", "given": "Chengxiang" }, "orcid": "0000-0002-1698-6754" }, { "id": "Mitrovic-S", "name": { "family": "Mitrovic", "given": "Slobodan" }, "orcid": "0000-0001-8913-8505" }, { "id": "Anzenberg-E", "name": { "family": "Anzenberg", "given": "Eitan" } }, { "id": "Kisielowski-C", "name": { "family": "Kisielowski", "given": "Christian" }, "orcid": "0000-0001-6425-0779" }, { "id": "Yano-Junko", "name": { "family": "Yano", "given": "Junko" }, "orcid": "0000-0001-6308-9071" }, { "id": "Jin-Jian", "name": { "family": "Jin", "given": "Jian" } }, { "id": "Gregoire-J-M", "name": { "family": "Gregoire", "given": "John M." }, "orcid": "0000-0002-2863-5265" } ] }, "title": "Discovering Ce-rich oxygen evolution catalysts, from high throughput screening to water electrolysis", "ispublished": "unpub", "full_text_status": "restricted", "note": "\u00a9 2014 American Chemical Society.", "abstract": "Discovering improved electrocatalysts for the oxygen evolution reaction (OER) is of great importance for efficient solar fuels\ngeneration, electrowinning of metals, regenerative fuel cells, and recharging metal air batteries. The slow kinetics of the 4-\nelectron OER requires large overpotentials to drive water oxidn. at appreciable current densities. Among the numerous compns.\ninvestigated, mixed metal oxides in the (Ni-Fe)Ox and (Ni-Co)Ox compn. spaces are among the most active and most studied\nOER catalysts. Although this technol. important reaction has been studied for more than 50 years, many of the mechanistic\ndetails remain under investigation. Lacking a robust fundamental understanding of the basic science and mechanistic details of\nmulti-electron heterogeneous electrocatalysis, an efficient high-throughput synthesis and property screening methodol. is\nwell-suited to discovering the requisite new catalytic materials. We have established high throughput methods to\nsystematically investigate the performance of pseudo-quaternary material libraries as OER electrocatalysts. We report a new Cerich\nfamily of active catalysts composed of earth abundant elements, which was discovered using high-throughput methods\nto produce 5456 discrete compns. in the (Ni-Fe-Co-Ce)Ox compn. space. The activity and stability of this new OER catalyst was\nverified by re-synthesis and extensive electrochem. testing of samples in a std. format in 1.0 M NaOH, as well as by operation in\na photovoltaic-powered electrolyzer for more than 100 h. The most interesting variations in activity lie in a pseudoternary crosssectional\nplane contg. 665 compns. Our detailed investigation of this psuedoternary cross-section has revealed systematic trends\nin Tafel slopes and electrochem. signals with compn., which provide a connection between the previously known Ni-Fe and newly\ndiscovered Ni-Co-Ce catalysts. Characterization of selected compns. by XRD, XPS, SEM, TEM, EDS, XRF mapping, and EXAFS,\nboth as-synthesized and after electrochem. testing, reveal important differences in nanostructure and stability along with the\nobsd. differences in electrochem. performance under OER conditions.", "date": "2014-03", "date_type": "published", "publisher": "Caltech Library", "id_number": "CaltechAUTHORS:20140425-081906501", "official_url": "https://resolver.caltech.edu/CaltechAUTHORS:20140425-081906501", "rights": "No commercial reproduction, distribution, display or performance rights in this work are provided.", "local_group": { "items": [ { "id": "JCAP" } ] }, "pub_year": "2014", "author_list": "Haber, Joel A.; Jung, Suho; et el." } ]