Anion-tuned nickel chalcogenides electrocatalysts for efficient 2e(−) ORR towards H(2)O(2) production in acidic media

Electrocatalytic 2e(−) oxygen reduction reaction (2e(−) ORR) is a promising approach to producing H(2)O(2) at ambient temperature and pressure especially in acidic media, which, however, is hindered by the high cost of precious metal-based electrocatalysts. Hence, the development of efficient earth-abundant electrocatalysts and reaction mechanism exploration for H(2)O(2) production by 2e(−) ORR in acidic solution are critically important but remain challenging at present. In this work, NiSe(2) has been developed as a novel and high-performance 2e(−) ORR electrocatalyst in acidic media, moreover, using nickel chalcogenides as the models, the influence of different anion species (Se(2)(2−), S(2)(2−), and O(2−)) on 2e(−) ORR electrocatalytic performance of the catalysts has been investigated. The synthesized NiSe(2) exhibits outstanding 2e(−) ORR performance of high selectivity (90%) and long-term durability (12 h). The maximum H(2)O(2) concentration of NiSe(2) reaches 988 ppm, which is the highest among all the reported transition metal chalcogenides. This work demonstrates a novel point of view in anion tuning for designing high-efficiency transition-metal-based electrocatalysts for 2e(−) ORR. [Image: see text] ELECTRONIC SUPPLEMENTARY MATERIAL: Supplementary material (additional experimental procedures, characterizations, and computational details) is available in the online version of this article at 10.1007/s12274-022-5160-2.