Chinese Journal of Catalysis ›› 2021, Vol. 42 ›› Issue (8): 1387-1394.DOI: 10.1016/S1872-2067(20)63647-6

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Role of transition-metal electrocatalysts for oxygen evolution with Si-based photoanodes

Rajender Boddulaa, Guancai Xiea,b, Beidou Guoa,b, Jian Ru Gonga,b,*()   

  1. aChinese Academy of Sciences (CAS) Center for Excellence in Nanoscience, CAS Key Laboratory of Nanosystem and Hierarchy Fabrication, National Center for Nanoscience and Technology, Beijing 100190, China
    bUniversity of Chinese Academy of Sciences, Beijing 100049, China
  • Received:2020-02-28 Accepted:2020-03-23 Online:2021-08-18 Published:2021-03-18
  • Contact: Jian Ru Gong
  • About author:*. Tel: +86-10-82545649; Fax: +86-10-62656765; E-mail: gongjr@nanoctr.cn
    First author contact:

    These authors contributed equally to this paper.

  • Supported by:
    This work was supported by the Strategic Priority Research Program of CAS(XDB36000000);National Natural Science Foundation of China(21422303);National Natural Science Foundation of China(21573049);National Natural Science Foundation of China(21872043);National Natural Science Foundation of China(22002028);Beijing Natural Science Foundation, Youth Innovation Promotion Association of CAS, the Belt and Road Special Program of CAS, and CAS President’s International Fellowship Initiative(2142036)

Abstract:

A comprehensive understanding of the role of the electrocatalyst in photoelectrochemical (PEC) water splitting is central to improving its performance. Herein, taking the Si-based photoanodes (n +p-Si/SiOx/Fe/FeOx/MOOH, M = Fe, Co, Ni) as a model system, we investigate the effect of the transition-metal electrocatalysts on the oxygen evolution reaction (OER). Among the photoanodes with the three different electrocatalysts, the best OER activity, with a low-onset potential of ∼1.01 VRHE, a high photocurrent density of 24.10 mA cm -2 at 1.23 VRHE, and a remarkable saturation photocurrent density of 38.82 mA cm -2, was obtained with the NiOOH overlayer under AM 1.5G simulated sunlight (100 mW cm -2) in 1 M KOH electrolyte. The optimal interfacial engineering for electrocatalysts plays a key role for achieving high performance because it promotes interfacial charge transport, provides a larger number of surface active sites, and results in higher OER activity, compared to other electrocatalysts. This study provides insights into how electrocatalysts function in water-splitting devices to guide future studies of solar energy conversion.

Key words: Solar water splitting, Artificial photosynthesis, Oxygen evolution reaction, Photoanode, Interfacial engineering, Transition-metal electrocatalyst