Ultrathin NiS2 nanocages with hierarchical-flexible walls and rich grain boundaries for efficient oxygen evolution reaction

• Published in: Chinese chemical letters p. 109940
• Main Authors: Luo, Chupeng, Su, Keying, Yang, Shan, Liang, Yujia, Tang, Yawen, Qiu, Xiaoyu
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.04.2024
• Subjects: Grain boundaries; Kinetics control; Nickel sulfide; Oxygen evolution reaction; Ultrathin nanocages; Grain boundaries; Kinetics control; Ultrathin nanocages; Oxygen evolution reaction; Nickel sulfide
• ISSN: 1001-8417; 1878-5964
• DOI: 10.1016/j.cclet.2024.109940

Shape control of nickel sulfide (NiS2) catalysts is beneficial for boosting their catalytic performances, which is vital to their practical application as a class of advanced non-noble electro-catalysts. However, precisely controlling the formation kinetics and fabricate ultrathin NiS2 nanostructures still remains challenge. Herein, we provide an injection rate-mediated method to fabricate ultrathin NiS2 nanocages (HNCs) with hierarchical walls, high-density lattice defects and abundant grain boundaries (GBs). Through mechanism analysis, we find the injection rate determines the concentration of S2− in the steady state and thus control the growth pattern, leading to the formation of NiS2 HNCs at slow etching kinetics and NiCo PBA@NiS2 frames at fast etching kinetics, respectively. Benefiting from the ultrathin and hierarchical walls that minimize the mass transport restrictions, the high-density lattice defects and GBs that offer abundant unsaturated reaction sites, the NiS2 HNCs exhibit obviously enhanced electrocatalytic activity and stability toward OER, with overpotential of 255 mV to reach 10 mA/cm2 and a Tafel slope of 27.44 mV/dec, surpassing the performances of NiCo PBA@NiS2 frames and commercial RuO2. In this work, we develop an injection rate-mediated method to fabricate ultrathin NiS2 nanocages with hierarchical walls, high-density lattice defects and abundant grain boundaries. The as-prepared NiS2 nanocages can realize efficient electro-catalysis for oxygen evolution reaction in terms of the high specific activity, favorable kinetics, superior durability, and rapid charge transfer. [Display omitted]