Preparation of CuBi2O4 photocathodes for overall water splitting under visible light irradiation. (1st November 2021)

• Record Type: Journal Article
• Authors: Jiang, Zhongyong; Geng, Huimin; Cai, Xiaoyan; Mao, Liang; Zhao, Yulong; Gu, Xiuquan
• Is Part Of: Materials science in semiconductor processing. Volume 134(2021)
• Publication Date: 2021-11-01
• Subjects: CuBi2O4 -- Layer thickness -- Tandem cell -- Photoelectrochemical; Semiconductors -- Periodicals; Integrated circuits -- Materials -- Periodicals; Semiconducteurs -- Périodiques; Circuits intégrés -- Matériaux -- Périodiques; Electronic journals; 621.38152
• DOI: 10.1016/j.mssp.2021.105989
• Languages: English
• ISSNs: 1369-8001

Abstract

Abstract: In this study, the CuBi2 O4 films were prepared by a facile drop-casting method for visible-light-driven water splitting, while the effect of film thickness and annealing temperature on the actual photoelectrochemical (PEC) performance were investigated. The annealing temperature was optimized as 550 °C. With increasing the layer number, the PEC performance was firstly increased and then decreased, reaching a maximum photocurrent density of 1.1 mA/cm 2 at a layer number of 3 under a bias of 0 V vs. reverse hydrogen electrode (RHE). Besides, both the electrochemical impedance and photoluminescence (PL) spectra were collected to reveal the mechanism underlying the performance changes. It was found that the enhanced PEC performance was attributed to high specific surface area and broad spectral response of CuBi2 O4 photocathodes. Moreover, a tandem PEC cell was constructed by combining CuBi2 O4 with a ZnIn2 S4 photoanode for unbiased solar water splitting. The photocurrent density at the joint point was 0.13 mA/cm 2, corresponding to an unbiased solar water splitting efficiency of 0.056%. This work shows that CuBi2 O4 has a good potential as a photocathode for solar-driven overall water splitting. Highlights: CuBi2 O4 photocathodes have been prepared by drop-casting. Effect of film thickness was investigated on surface morphology and PEC performance. Excellent PEC performance is ascribed to efficient visible light absorption and carrier transport. PEC tandem cell was constructed for overall water splitting, leading to a photocurrent of ~0.0309 mA/cm 2 under zero bias.