title: Adjusting the Crystallinity of Mesoporous Spinel CoGa2O4 for Efficient Water Oxidation.
abstract: Effective and stable electrocatalysts (ECs) are of great importance for the modification of semiconductor (SC) photoanodes, to achieve efficient photoelectrochemical (PEC) water splitting. Herein we demonstrate that the low-crystallinity mesoporous spinel CoGa2O4 oxygen evolution catalyst (OEC), exhibiting excellent bulk electrocatalytic stability and activity for oxygen-evolving reaction (OER), obviously improved water oxidization on a-Fe2O3 photoanode. Low crystallinity not only balances the stability and activity for ECs themselves but facilitates formation of adjustable Schottky junctions between ECs and SCs. Those would contribute to surface state passivation and photogenerated hole extraction, leading to lower onset potential and larger photocurrent. Thus, our finding suggests that low crystallinity could serve as a beneficial feature of ECs to achieve efficient PEC water splitting, owing to its preponderant tendency for the improvement of interface reaction kinetics.
authors.affiliation: National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Jiangsu Provincial Key Laboratory for Nanotechnology, Eco-Materials and Renewable Energy Research Center (ERERC), College of Engineering and Applied Sciences, and ‡School of Physics, Nanjing University , Nanjing, Jiangsu 210093, China.
authors.forename: Zhe
authors.initials: Z
authors.lastname: Xu
authors.affiliation: National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Jiangsu Provincial Key Laboratory for Nanotechnology, Eco-Materials and Renewable Energy Research Center (ERERC), College of Engineering and Applied Sciences, and ‡School of Physics, Nanjing University , Nanjing, Jiangsu 210093, China.
authors.forename: Shi-Cheng
authors.initials: SC
authors.lastname: Yan
authors.affiliation: National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Jiangsu Provincial Key Laboratory for Nanotechnology, Eco-Materials and Renewable Energy Research Center (ERERC), College of Engineering and Applied Sciences, and ‡School of Physics, Nanjing University , Nanjing, Jiangsu 210093, China.
authors.forename: Zhan
authors.initials: Z
authors.lastname: Shi
authors.affiliation: National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Jiangsu Provincial Key Laboratory for Nanotechnology, Eco-Materials and Renewable Energy Research Center (ERERC), College of Engineering and Applied Sciences, and ‡School of Physics, Nanjing University , Nanjing, Jiangsu 210093, China.
authors.forename: Ying-Fang
authors.initials: YF
authors.lastname: Yao
authors.affiliation: National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Jiangsu Provincial Key Laboratory for Nanotechnology, Eco-Materials and Renewable Energy Research Center (ERERC), College of Engineering and Applied Sciences, and ‡School of Physics, Nanjing University , Nanjing, Jiangsu 210093, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhou
authors.affiliation: National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Jiangsu Provincial Key Laboratory for Nanotechnology, Eco-Materials and Renewable Energy Research Center (ERERC), College of Engineering and Applied Sciences, and ‡School of Physics, Nanjing University , Nanjing, Jiangsu 210093, China.
authors.forename: Hao-Yu
authors.initials: HY
authors.lastname: Wang
authors.affiliation: National Laboratory of Solid State Microstructures, Collaborative Innovation Center of Advanced Microstructures, Jiangsu Provincial Key Laboratory for Nanotechnology, Eco-Materials and Renewable Energy Research Center (ERERC), College of Engineering and Applied Sciences, and ‡School of Physics, Nanjing University , Nanjing, Jiangsu 210093, China.
authors.forename: Zhi-Gang
authors.initials: ZG
authors.lastname: Zou
keywords: electrocatalysis; low-crystallinity electrocatalyst; photoanode modification; photoelectrocatalysis; water oxidation reaction