Efficient BiVO4 Photoanode with an Excellent Hole Transport Layer of CuSCN for Solar Water Oxidation

• Published in: Advanced energy materials 2024-05, Vol.14 (17), p.n/a
• Main Authors: Liu, Yan, Zhang, Zhiyong, Wang, Kang, Tan, Xianglong, Chen, Junru, Ren, Xiaoliang, Jiang, Feng
• Format: Article
• Language: English
• Subjects: Bismuth oxides; BiVO4; Charge efficiency; Charge transfer; Charge transport; Conduction bands; Current efficiency; CuSCN; Efficiency; Energy levels; hole transport layer; Hydrogen evolution; Oxidation; Photoanodes; Photoelectric effect; Photoelectric emission; Photovoltaic cells; Solar cells; Solar radiation; solar water oxidation; Stability; Thiocyanates; Vanadates
• ISSN: 1614-6832; 1614-6840
• DOI: 10.1002/aenm.202304223

Bismuth vanadate (BiVO4) is reported as a key material in photoelectrocatalysis owing to high theoretical efficiency, relatively narrow band gap of 2.4 eV, and favorable conduction band edge position for hydrogen evolution. However, the sluggish hole transport dynamics lead to slow photogenerated charge separation and transport efficiencies, which result in charge recombination due to aggregation. Herein, a novel hole transport layer of copper(I) thiocyanate (CuSCN) with the aim of significantly enhancing the efficiency of charge transport and stability of BiVO4 photoanodes is reported. The introduction of the hole transport layer could provide an appropriate intermediate energy level for photogenerated hole transfer and avoid charge recombination and trapping. After a photoassisted electrodeposition process of NiCoFe‐Bi catalysis, the obtained photoanode achieves a photocurrent density of 5.6 mA cm−2 at 1.23 V versus reversible hydrogen electrode under AM 1.5 G simulated solar radiation, and an applied bias photon to current efficiency of 2.31%. With the CuSCN layer, BiVO4 photoanode presented impressive stable photocurrent during 50 h continuous illumination. Meanwhile, the unbiased tandem device of the NiCoFe‐Bi/CuSCN/BiVO4 photoanode and the Si solar cell exhibit a solar‐to‐hydrogen efficiency of 5.75% and excellent stability for 14 h. Herein, a novel hole transport layer of CuSCN with the aim of significantly enhancing the efficiency of charge transport and stability of BiVO4 photoanodes is reported. CuSCN/BiVO4 photoanode presents impressive stable photocurrent over 50 h and the tandem device of CuSCN/BiVO4 photoanode with Si solar cell exhibits a solar‐to‐hydrogen efficiency of 5.75%.