Cation doping driven performance optimization of MoS <sub>2</sub> nanoarrays for nitrate and sulfide co-electrolysis
Miaosen Yang, Xianghua Hou, Rao Fu, Zhiwei Wang, Cejun Hu, Guangzhi Hu, Longchao Zhuo, Xijun Liu
Abstract
Simultaneous nitrate reduction and sulfide oxidation reactions (NO<sub>3</sub>RR and SOR) to generate valuable chemicals represent an appealing strategy for green synthesis; however, the sluggish kinetics seriously hinder their application. Herein, we report that Ni dopants can optimize the electronic structure of MoS<sub>2</sub>, which thus favors the adsorption of reactants/intermediates and reduces the corresponding energy barriers. As a result, the designed catalyst shows a maximal Faradic efficiency of 88.4% and a corresponding yield rate of 66.7 μmol h<sup>‒1</sup> cm<sup>‒2</sup> for NH<sub>3</sub> synthesis, accompanied by a high robustness over 60 h. Besides, it can also trigger the SOR activity with a low potential of 0.105 V <em>vs.</em> RHE to produce 10 mA cm<sup>‒2</sup>, far smaller than that needed for conventional water oxidation (1.545 V <em>vs.</em> RHE). Accordingly, a coupling system with NO<sub>3</sub>RR and SOR is constructed for synchronous formation of value-added products on both anode and cathode. This work demonstrates an attractive attempt to construct advanced MoS<sub>2</sub>-based catalysts towards electrosynthesis.