Wu Kaili, Wang Chenjing, Lang Xiufeng, Cheng Jiarun, Wu Hongjing, Lyu Chaojie, Lau Woon-Ming, Liang Zhengwenda, Zhu Xixi, Zheng Jinlong
Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China; Shunde Innovation School, University of Science and Technology Beijing, Foshan 528399, China.
Beijing Advanced Innovation Center for Materials Genome Engineering, University of Science and Technology Beijing, Beijing 100083, China.
J Colloid Interface Sci. 2023 Oct 21;654(Pt B):1040-1053. doi: 10.1016/j.jcis.2023.10.106.
The integration of interface engineering and vacancy engineering was a feasible way to develop highly efficient electrocatalysts toward water electrolysis. Herein, we designed CoSe/MoSe heterojunction nanosheets with abundant Se vacancies (V-CoSe/MoSe) for electrocatalytic water splitting. In the V-CoSe/MoSe electrocatalyst, the electrons more easily transferred from CoSe to MoSe, and interface engineering not only modulated the electronic structure, but also supplied more heterointerfaces and catalytic sites. After chemical etching, partial Se atoms were eliminated, which further activated the inert plane of the V-CoSe/MoSe electrocatalyst and induced electron redistribution. The removal of surface Se atoms was also beneficial to expose inner reactive sites, which promoted adsorption toward reaction intermediates. Density functional theory calculations revealed that interface engineering and vacancy engineering collaboratively optimized the adsorption energy of the V-CoSe/MoSe electrocatalyst toward the intermediate H* during the hydrogen evolution reaction process, leading to better electrocatalytic activity. The density of state diagram manifested the refined electronic structure of the V-CoSe/MoSe electrocatalyst, and it exhibited a higher electronic state near the Fermi level, which indicated superior electronic conductivity, facilitating electron transport during the catalytic process. In alkaline media, the V-CoSe/MoSe electrocatalyst delivered low overpotentials of merely 74 and 242 mV to obtain 10 mA cm toward hydrogen evolution reaction and oxygen evolution reaction. This work illustrated the feasibility of combining two or more strategies to develop high-performance catalysts for water electrolysis.
界面工程与空位工程相结合是开发高效水电解电催化剂的可行途径。在此，我们设计了具有丰富硒空位的CoSe/MoSe异质结纳米片（V-CoSe/MoSe）用于电催化水分解。在V-CoSe/MoSe电催化剂中，电子更容易从CoSe转移到MoSe，界面工程不仅调节了电子结构，还提供了更多的异质界面和催化位点。化学蚀刻后，部分硒原子被去除，这进一步激活了V-CoSe/MoSe电催化剂的惰性平面并诱导了电子重新分布。表面硒原子的去除也有利于暴露内部活性位点，促进对反应中间体的吸附。密度泛函理论计算表明，界面工程和空位工程协同优化了V-CoSe/MoSe电催化剂在析氢反应过程中对中间体H*的吸附能，从而具有更好的电催化活性。态密度图显示了V-CoSe/MoSe电催化剂精细的电子结构，并且它在费米能级附近表现出更高的电子态，这表明其具有优异的电子导电性，有利于催化过程中的电子传输。在碱性介质中，V-CoSe/MoSe电催化剂在析氢反应和析氧反应中仅需74和242 mV的低过电位即可达到10 mA cm。这项工作说明了结合两种或更多策略来开发用于水电解的高性能催化剂的可行性。
