Preparation of double-layered Co−Ci/NiFeOOH co-catalyst for highly meliorated PEC performance in water splitting

• Published in: Advanced Powder Materials 2022-07, Vol.1 (3), p.100024, Article 100024
• Main Authors: Hu, Xingsheng, Li, Yan, Wei, Xinxin, Wang, Lei, She, Houde, Huang, Jingwei, Wang, Qizhao
• Format: Article
• Language: English
• Subjects: BiVO4; Co-catalyst; Cobalt−carbonate (Co−Ci); Water splitting
• ISSN: 2772-834X; 2772-834X
• DOI: 10.1016/j.apmate.2021.11.010

The cobalt−carbonate (CoCi)/NiFeOOH double-layer co-catalyst was prepared on bismuth vanadate (BiVO4). Compared with the same type of electrode (Co−Pi/NiFeOOH/BiVO4 and Co−Sil/NiFeOOH/BiVO4), the photoelectrochemical (PEC) performance of the composite electrode presents the most excellent performance. The Co−Ci/NiFeOOH/BiVO4 electrode prepared by photoelectric deposition (PED) achieves a photocurrent density of 4.1 ​mA/cm2 at 1.23 ​V vs RHE, and the applied bias photon-current efficiency (ABPE) is up to 0.95%. In addition, with the help of the equivalent circuit fitting in electrochemical impedance spectroscopy (EIS), the charge transfer resistance (Rct) of Co−Ci/NiFeOOH/BiVO4 is only 108.9 ​Ω, which is 16% that of BiVO4. The enhanced PEC performance of Co−Ci/NiFeOOH/BiVO4 in the double-layer cocatalyst system is attributed to the outstanding advantages of Co−Ci cocatalyst in oxygen vacancy defects, superior to other cobalt-based catalysts in promoting charge transfer and improving the kinetics of water oxidation. This makes Co−Ci co-catalyst become one of the favorable competitors in the field of photoelectric catalysis. [Display omitted]