Triggering heteroatomic interdiffusion in one-pot-oxidation synthesized NiO/CuFeO2 heterojunction photocathodes for efficient solar hydrogen production from water splitting

• Published in: Rare metals 2023-03, Vol.42 (3), p.853-861
• Main Authors: Han, Fei, Xu, Wei, Jia, Chun-Xu, Chen, Xiang-Tao, Xie, Ying-Peng, Zhen, Chao, Liu, Gang
• Format: Article
• Language: English
• Subjects: Biomaterials; Chemistry and Materials Science; Copper; Current carriers; Density; Energy; Fluorine; Heterojunctions; Heterostructures; Hydrogen production; Interdiffusion; Materials Engineering; Materials Science; Metallic Materials; Nanoscale Science and Technology; Nickel oxides; Original Article; Oxidation; Photocathodes; Photoelectric effect; Photoelectric emission; Physical Chemistry; Substrates; Tin oxides; Water splitting
• ISSN: 1001-0521; 1867-7185
• DOI: 10.1007/s12598-022-02177-w

Delafossite CuFeO 2 is a promising photocathode material for cost-efficiently photoelectrochemical (PEC) water splitting, but the unfavorable conductivity and fast recombination dynamics of photogenerated carriers limit its PEC activity for water reduction. Here, we developed a heterostructure photocathode consisting of the Cu-doped NiO (Cu:NiO) hole selective layer (HSL) and Ni-doped CuFeO 2 (Ni:CuFeO 2 ) active layer by simply annealing a homogeneous Cu–Fe oxalate layer grown on the Ni film deposited on the fluorine doped tin oxide (FTO) substrate. The obtained heterostructure of Cu:NiO/Ni:CuFeO 2 with enhanced charge carrier transportability and high-quality interface greatly promotes the separation of photogenerated carriers. Accordingly, the Cu:NiO/Ni:CuFeO 2 photocathode exhibits a high photocurrent density of ~ 0.9 mA·cm −2 at 0.2 V (vs. reversible hydrogen electrode, RHE), outperforming most of the reported bare CuFeO 2 photocathodes in the literature. And the photocurrent density can be further improved to 1.2 mA·cm −2 after decorating NiS x cocatalyst. Graphical abstract