Hu Kailong, Ohto Tatsuhiko, Nagata Yuki, Wakisaka Mitsuru, Aoki Yoshitaka, Fujita Jun-Ichi, Ito Yoshikazu
Institute of Applied Physics, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, 305-8573, Japan.
Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama, Toyonaka, 560-8531, Japan.
Nat Commun. 2021 Jan 8;12(1):203. doi: 10.1038/s41467-020-20503-7.
Graphene-covering is a promising approach for achieving an acid-stable, non-noble-metal-catalysed hydrogen evolution reaction (HER). Optimization of the number of graphene-covering layers and the density of defects generated by chemical doping is crucial for achieving a balance between corrosion resistance and catalytic activity. Here, we investigate the influence of charge transfer and proton penetration through the graphene layers on the HER mechanisms of the non-noble metals Ni and Cu in an acidic electrolyte. We find that increasing the number of graphene-covering layers significantly alters the HER performances of Ni and Cu. The proton penetration explored through electrochemical experiments and simulations reveals that the HER activity of the graphene-covered catalysts is governed by the degree of proton penetration, as determined by the number of graphene-covering layers.
石墨烯包覆是实现酸稳定、非贵金属催化析氢反应（HER）的一种有前景的方法。优化石墨烯包覆层数以及化学掺杂产生的缺陷密度对于在耐腐蚀性和催化活性之间取得平衡至关重要。在此，我们研究了电荷转移和质子穿透石墨烯层对酸性电解质中非贵金属镍和铜的析氢反应机制的影响。我们发现增加石墨烯包覆层数会显著改变镍和铜的析氢性能。通过电化学实验和模拟探索的质子穿透表明，石墨烯包覆催化剂的析氢活性由质子穿透程度决定，而质子穿透程度由石墨烯包覆层数决定。
