Controlled synthesis and fine-tuned interface of NiS nanoparticles/Bi2WO6 nanosheets heterogeneous as electrocatalyst for oxygen evolution reaction

• DOI: 10.1016/j.apsusc.2020.146718
• Publication Date: 2020-05-23T15:26:13Z
• Authors: Junqi Li; Xiaotao Xu; Beiyi Zhang; Wenfei Hou; Siye Lv; Yunli Shi
• Keywords: 02 engineering and technology; 0210 nano-technology; 7. Clean energy

Abstract Heterojunction engineering is one of the commonly used methods for developing electrocatalyst to enhance catalytic activity and stability due to the unique interfacial coupling synergistic. Herein, a strong-coupling 0D/2D NiS/Bi2WO6 heterogeneous electrocatalyst was successfully synthesized through a facile hydrothermal and calcination route. Electrochemistry results revealed that the NiS/Bi2WO6-4 catalyst not only exhibited competitive OER catalytic activity with smaller overpotential (527 mV) and lower Tafel slope (238 mV dec−1) but also delivered long-term stability (at 1.73 V vs. RHE for 13 h). Such excellent properties are mainly due to (1) the substantial active sites are provided by NiS nanoparticles evenly anchored on Bi2WO6 nanosheets, (2) the O-Ni-S bond structure acts as the bridge in heterointerface, which improves the charge and mass transfer rate as well as stabilizes the heterostructure, (3) Most importantly, the bonding of Ni and O changes the valence-bond environment around the nickel species, which is more conducive to balance between the adsorption of OH− and the desorption of O2 in the oxygen evolution reaction. This non-precious NiS/Bi2WO6 heterojunction catalyst is designed with the 0D/2D heterointerface engineering, which may open a new train of thought to design new promising and highly efficient OER electrocatalysts.