Toward efficient and stable solar water splitting

Miao Zhong (钟苗)

特任研究员, 人工光合成项目ARPChem, 日本新能源产能技术开发机构NEDO博士后,


时间:5月6日 周五 下午2:00-3:00

Solar energy is clean and remarkably abundant electromagnetic radiation energy available on earth. Efficient storage of intermittent solar energy in renewable hydrogen fuels by photoelectrochemical (PEC) water splitting represents the yet utmost promising fashion for sustainable solar energy recovery to meet the worldwide booming energy demands with limited environmental pollutions. However, stubborn challenges in developing high-performance photoanodes have long thwarted practical applications of PEC water splitting devices.
In this report, we demonstrate efficient photoanodes made of solid solution ZnO:GaN and BiVO4 respectively for stable solar water splitting. For solid solution ZnO:GaN photoanodes, we realized visible light sensitive and conductive ZnO:GaN nanowire-array-on-a-film structures with high in-plane and out-of-plane crystalline quality[1]. For BiVO4 photoanodes, we demonstrated scalable fabrication of micro/nano crystalline BiVO4 particles on sputtered Ti metal via “particle transfer” processes[2,3]. Special attention was paid to passivate surface states of particle transferred BiVO4/Ti photoanodes by loading of CoOx and conformal depositing of p type NiO layers. A largely improved photovoltage was realized to thermodynamically enhance water oxidation reactions. The in situ formed hydroxyl-ion permeable NiOOH during PEC measurements further enables dual water oxidation catalysts of CoOx and NiOOH that drastically improves water oxidation kinetics and stability. The fabricated single junction BiVO4 photoanodes achieved 2% solar to hydrogen conversion efficiency which is the top efficiency among all the water splitting photoanodes.

[1] M. Zhong, J.-J. Delaunay et al. Energy Environ. Sci., 2014, 7, 1693.
[2] T. Minegishi, K. Domen et al. Chem. Sci. 2013, 4, 1120−1124.
[3] M. Zhong, T. Hisatomi, K. Domen et al. J. Am. Chem. Soc. 2015, 137, 5053−5060.

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