Ce-doped nise nanosheets on carbon cloth for electrochemical water-splitting

Abstract

Developing an affordable and efficient electrocatalyst for bifunctional activity is crucial for the advancement of water electrolysis technology. Doping with foreign atoms in electrocatalysts can tune the electronic properties, which further improves the water-splitting process. Herein, we have developed Ce-doped Ni0.85Se as a bifunctional electrocatalyst in an alkaline medium. The hydrothermal method was used to develop a two-dimensional (2D) nanosheet of the Ce-doped Ni0.85Se electrocatalyst. The as-developed pristine and doped electrocatalysts were characterized through various techniques. The optimized Ce0.1Ni0.85Se electrocatalyst represents −0.238 and 1.56 V vs reversible hydrogen electrode as an onset potential for hydrogen and oxygen evolution reactions, respectively, to generate 20 and 50 mA/cm2 current density. The Ce0.1Ni0.85Se electrocatalyst works as a suitable cell in an alkaline medium with 1.73 V to generate 10 mA/cm2 and 24 h stability. The introduction of Ce doping plays a pivotal role in tuning the electronic environment and facilitating a synergistic effect, ultimately improving the overall efficiency. Moreover, the active sites for water splitting were generated by expansion and distortion in the Ni0.85Se lattice. The enhanced specific surface area and porous 2D nanosheets of the doped sample are beneficial for water splitting. The theoretical results also prove that after doping with Ce, the catalyst has zero band gap, optimum Gibbs hydrogen adsorption energy, and an electronic state are the reasons for improved electrocatalytic performance. The actual active sites in the Ce-doped Ni0.85Se electrocatalyst were determined with density functional theory calculations. Therefore, this idea can generate a route for developing a doped electrocatalyst with efficient and stable activity.