In this study, we explore cocatalyst-free, single-crystalline, and epitaxial thin film zinc telluride (ZnTe) as a photocathode for CO2-to-CO conversion. The study systematically examines the impact of electronic properties and crystal orientation using nitrogen-doped, p-type ZnTe (ZnTe:N) photocathodes grown on GaAs substrates by molecular beam epitaxy (MBE). Heavily doped ZnTe:N ([p] ≅ 1020 cm–3) with a (100) orientation achieves a selective CO2-to-CO Faradaic efficiency of 62% over a 200-mV potential window (with current densities of ∼0.1 mA·cm–2) without additional surface modifications. ZnTe:N of (100), (110), and (111) crystal orientations demonstrate different photoactivity, with the (100) and (110) orientations exhibiting three times higher photocurrent density compared to the (111) orientation despite their similar electronic properties. Overall, this study provides a foundation for further development of ZnTe-based tandem devices for photoelectrochemical CO2 reduction.
", "doi": "10.1021/acsaem.5c03133", "issn": "2574-0962", "publisher": "American Chemical Society", "publication": "ACS Applied Energy Materials", "publication_date": "2026-03-23", "series_number": "6", "volume": "9", "issue": "6", "pages": "3005-3015" }, { "id": "authors:mn25m-vcq03", "collection": "authors", "collection_id": "mn25m-vcq03", "cite_using_url": "https://authors.library.caltech.edu/records/mn25m-vcq03", "type": "article", "title": "Electrodeposited Pt on NiFe layered double hydroxide/Ni foam electrode for an extremely active and durable electrocatalyst for ammonia oxidation reaction", "author": [ { "family_name": "Lee", "given_name": "Jiwoo" }, { "family_name": "Lee", "given_name": "Sol A", "orcid": "0000-0003-3163-2302", "clpid": "Lee-Sol-A" }, { "family_name": "Kim", "given_name": "Jaehyun" }, { "family_name": "Lee", "given_name": "Tae Hyung", "orcid": "0000-0003-4501-3166" }, { "family_name": "Cheon", "given_name": "Woo Seok" }, { "family_name": "Choi", "given_name": "Sungkyun" }, { "family_name": "Park", "given_name": "Sung Hyuk", "orcid": "0000-0003-0105-6025" }, { "family_name": "Jang", "given_name": "Ho Won", "orcid": "0000-0002-6952-7359" } ], "abstract": "With the increasing demand for clean energy to achieve a carbon-neutral society, ammonia (NH3) has emerged as a hydrogen carrier due to its high hydrogen energy density, low volatility, and its ability for long-term storage and transport. Ammonia electrolysis is a promising hydrogen generation technology because it requires low theoretical voltage (0.06V) and mild operating conditions, such as relatively low temperatures and pressures. Platinum (Pt) is a selective and active electrocatalyst for ammonia oxidation to nitrogen, with the lowest overpotential among single-metal catalysts. However, the poisoning effect that blocks the catalytic active sites limits its long-term catalytic performance. In this work, we report a Pt-deposited NiFe layered double hydroxide (LDH) electrocatalyst prepared on Ni foam that achieves high hydrogen production efficiency through its large specific surface area. Notably, we address the way of mitigating the poisoning of Pt/NiFe LDH catalysts using a pulse-cycling method applicable across various electrolyte conditions. This approach facilitates the desorption of adsorbed nitrogen intermediates responsible for poisoning, achieving 150h of operation without significant performance degradation \u2212 the longest stability reported for an ammonia oxidation electrocatalyst to date. This work presents a novel catalytic technology for long-term stable hydrogen production through ammonia electrolysis with low power consumption, representing a significant step toward advancing the commercial viability of hydrogen production through ammonia electrolysis.", "doi": "10.1016/j.apcatb.2025.125251", "issn": "0926-3373", "publisher": "Elsevier", "publication": "Applied Catalysis B: Environment and Energy", "publication_date": "2025-08-15", "volume": "371", "pages": "125251" }, { "id": "authors:abm55-6gj84", "collection": "authors", "collection_id": "abm55-6gj84", "cite_using_url": "https://authors.library.caltech.edu/records/abm55-6gj84", "type": "article", "title": "Solar production of fuels from CO\u2082 with high efficiency and stability via in situ transformation of Bi electrocatalysts", "author": [ { "family_name": "Cheon", "given_name": "Woo Seok", "orcid": "0000-0002-9026-6720" }, { "family_name": "Ji", "given_name": "Su Geun" }, { "family_name": "Kim", "given_name": "Jaehyun" }, { "family_name": "Choi", "given_name": "Sungkyun" }, { "family_name": "Yang", "given_name": "Jin Wook" }, { "family_name": "Jun", "given_name": "Sang Eon" }, { "family_name": "Kim", "given_name": "Changyeon" }, { "family_name": "Bu", "given_name": "Jeewon" }, { "family_name": "Park", "given_name": "Sohyeon" }, { "family_name": "Lee", "given_name": "Tae Hyung" }, { "family_name": "Wang", "given_name": "Jinghan" }, { "family_name": "Kim", "given_name": "Jae Young" }, { "family_name": "Lee", "given_name": "Sol A", "orcid": "0000-0003-3163-2302", "clpid": "Lee-Sol-A" }, { "family_name": "Kim", "given_name": "Jin Young", "orcid": "0000-0001-7746-9972" }, { "family_name": "Jang", "given_name": "Ho Won" } ], "abstract": "The sustainable electrocatalytic reduction of carbon dioxide into solar fuels offers a potential pathway to mitigate the impact of greenhouse gas-induced climate change. Here, we successfully achieved a high solar-to-fuel (STF) efficiency of 11.5% by integrating a low-cost tandem solar cell with robust, high-performance, non-precious metal-based electrocatalysts. The bismuth-based cathode exhibited a high formic acid selectivity of 97.2% at a potential of −1.1 VRHE, along with an outstanding partial current density of 32.5 mA cm−2. Furthermore, upon undergoing more than 24 hours of electrolysis, we observed an enhancement in the catalytic activity. Through comprehensive analysis including in situ Raman spectroscopy and density functional theory (DFT) calculations, we elucidated that the in situ transformation of bismuth into bismuth subcarbonate (BOC) induces multiple effects: (i) the formation of grain boundaries between phases with distinct lattice parameters, (ii) electronic modulation due to defect formation, and (iii) changes in the binding modes of key reaction intermediates on active sites, resulting in the stabilization of *OCHO species. The cause of these phase transformations was attributed to the structural similarity between the cathode template and BOC. The sustainability of the STF efficiency sets a new benchmark for all cost-effective photovoltaic-coupled electrochemical systems.
", "doi": "10.1039/d4ey00209a", "issn": "2753-801X", "publisher": "Royal Society of Chemistry", "publication": "EES Catalysis", "publication_date": "2025", "series_number": "1", "volume": "3", "issue": "1", "pages": "140-151" } ]