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Bias‐Free Solar Water Splitting by Tetragonal Zircon BiVO 4 Nanocrystal Photocathode and Monoclinic Scheelite BiVO 4 Nanoporous Photoanode
Author(s) -
Liang Xizhuang,
Wang Peng,
Tong Fengxia,
Liu Xiaolei,
Wang Cong,
Wang Minrui,
Zhang Qianqian,
Wang Zeyan,
Liu Yuanyuan,
Zheng Zhaoke,
Dai Ying,
Huang Baibiao
Publication year - 2021
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.202008656
Subject(s) - photocathode , materials science , nanoporous , tetragonal crystal system , monoclinic crystal system , energy conversion efficiency , water splitting , kesterite , solar cell , optoelectronics , nanotechnology , phase (matter) , crystallography , catalysis , chemistry , physics , electron , organic chemistry , quantum mechanics , crystal structure , biochemistry , photocatalysis , czts
p‐type tetragonal zircon BiVO 4 nanocrystal photocathodes (P‐BVO) and n‐type monoclinic scheelite BiVO 4 nanoporous photoanodes (N‐BVO) are prepared by a hydrothermal method and an electrochemical synthesis method, respectively. Pt nanoparticles and cobalt‐phosphate (Co‐Pi) as co‐catalysts are loaded by an electrodeposition way to improve the photoelectrochemical (PEC) performance of BiVO 4 (BVO) electrodes. After modification, a monochromatic incident photon‐to‐current conversion efficiency (IPCE) of P‐BVO/Pt at 360 nm is improved by 2.2 times, and the highest IPCE of N‐BVO/Co‐Pi at 440 nm is increased by 1.7 times. The calculated electron‐hole separation yield and the charge carrier injection yield of N‐BVO/Co‐Pi at 1.23 V RHE are further improved to 80% and 86%, respectively. The surface modification also results in the latest ≈0.2% half‐cell solar‐to‐hydrogen energy conversion efficiency (HC‐STH) for a P‐BVO/Pt photocathode and a higher ≈1.16% half‐cell applied bias photon‐to‐current conversion efficiency (ABPE) for an N‐BVO/Co‐Pi photoanode. Furthermore, the prepared photoelectrodes are proved to have excellent stability for water splitting. Above all, a tandem‐type PEC cell containing the newly developed P‐BVO/Pt photocathode and an N‐BVO/Co‐Pi photoanode is built for the first time, which evolves H 2 and O 2 at a stoichiometric ratio of 2:1 with a bias‐free STH of 0.14%.