5.7% Efficiency Si Photoanodes for Solar Water Splitting Catalyzed by Vertically Grown and Oxygen‐Vacancy‐Rich NiFe Hydroxides

• DOI: 10.1002/adsu.202300022
• Publication Date: 2023-04-01T02:04:01Z
• Authors: Peng Zhu; Cong Chen; Junxia Shen; Zhihe Wei; Yongjie Wang; Yazhou Zhang; Wen Dong; Yang Peng; Ronglei Fan; Mingrong Shen
• Keywords: Oxygen evolution; Nanosheet

Abstract The sluggish oxygen evolution reaction (OER) kinetics and adverse charge transfer stability at the multi‐interfaces from Si to electrolyte severely impede application of photoanodes. Herein, vacancy (OV)‐rich NiFe‐layered hydroxides (NiFe‐OH) nanosheet arrays are vertically orientated on Ni‐protected photoanodes by a facile solvothermal method followed hot Fe ion‐exchange treatment. By virtue formation OVs NiFe‐OH nanosheets vertical contact between substrate, as‐prepared photoanode not only enables abundant active sites for OER but also boosts mass when compared traditional electro‐deposit samples. Moreover, Ni/Si benefits release interfacial stress thereby promotes electrode stability. Consequently, optimal shows an ultrahigh applied bias photon‐to‐current efficiency 5.7% good over 200 h, outdoing almost all recently reported