塔菲尔方程
钴
二硒醚
正交晶系
材料科学
催化作用
化学工程
介孔材料
纳米技术
无机化学
晶体结构
化学
结晶学
电化学
冶金
物理化学
有机化学
电极
工程类
硒
作者
Su-Hyun Yang,Gi Dae Park,Jinkoo Kim,Yun Chan Kang
标识
DOI:10.1016/j.cej.2021.130341
摘要
Cobalt diselenide (CoSe2) has been considered as a prospective hydrogen evolution reaction (HER) catalyst due to its good electrocatalytic activity and chemical stability under acidic conditions. In this regard, various strategies for effectively utilizing CoSe2 as an electrocatalyst have been introduced. However, to the best of our knowledge, the development of new strategies for the formation of cobalt diselenide with small crystal sizes within carbon substrates, as well as facilitating phase-controlling method to improve HER properties, has been rarely reported. Herein, we propose a new method that can control the location and crystal size of cobalt diselenide nanocrystals in hollow mesoporous carbon nanospheres (HC) by a facile impregnation method and one-step selenization process. In particular, the co-addition of cobalt nitrate and SeO2 into HC plays an important role in preventing cobalt diselenide particles from protruding to the outside of the HC by an immediate chemical reaction in the inner void of HC. Interestingly, by controlling the amount of impregnated SeO2 in HC, phase-controlling from the orthorhombic to cubic phase at the same heat treatment temperature is achieved. The optimized polymorphic CoSe2 loaded in HC exhibited a much higher HER performance, with a Tafel slope of 45.7 mV per decade (dec−1), than orthorhombic CoSe2 loaded in HC (53.9 mV dec−1) and cubic CoSe2 loaded in HC (50.8 mV dec−1). The synergistic effects of the crystal size and location of CoSe2 in the HC and its phase properties contribute to the outstanding HER performance.
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