Modified Co electronic states in double-anionic CoPS nanocrystals induce highly efficient electrocatalytic hydrogen evolution
Modified Co electronic states in double-anionic CoPS nanocrystals induce highly efficient electrocatalytic hydrogen evolution
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DOI：
10.1016/j.jallcom.2022.166114
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发表时间：
2022-07
影响因子：
6.2
通讯作者：
Ka Wang;Shuo Liu;Kaihui Mao;Zhiqiang Chu;Yixian Wang;Jian Chen;Shancheng Yan;Jun Dai;
中科院分区：
文献类型：
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作者：
Ka Wang;Shuo Liu;Kaihui Mao;Zhiqiang Chu;Yixian Wang;Jian Chen;Shancheng Yan;Jun Dai;
具有半金属性质的黄铁矿型CoS2作为一种非贵金属电催化剂，具有廉价、环境友好、可持续发展等优点，在能源领域受到了广泛关注。特别地，它可以从Co电子态产生显著的自旋极化电子以运行有效的析氢反应（HER）。在这项工作中，我们专注于双阴离子CoPS纳米晶体（NC）和探索的电催化析氢性能。理论计算表明，磷的引入使Co原子的d带向费米面移动，使CoPS的表面活化能垒（0.98 eV）远低于CoS2的表面活化能垒（1.41 eV）.通过在CoS2包覆的碳纤维纸上生长表面修饰CoPS纳米粒子的棒状Co3（PO4）2作为电化学阴极，发现这种复合结构由于具有较大的比表面积，可以有效提高H2的逸出效率。电流密度在47 mV时达到10 mA cm− 2。tafel斜率仅为52 mV dec−1，远小于CoS2。光谱表征表明，CoPS NC的改性电子态和化合物中良好的电荷传输动力学是所观察到的高效HER性能的原因。该研究为设计和制备具有双阴离子协同效应和分级活性的高效电催化剂提供了一种有用的策略。
Pyrite-type CoS2with half-metal properties has attracted more attention in the energy field because it is a kind of non-precious metal electrocatalyst with inexpensive, environmentally friendly, and sustainable merits. Particularly, it can produce significant spin-polarized electrons from Co electronic states to run efficient hydrogen evolution reactions (HER). In this work, we focus attention on double-anionic CoPS nanocrystals (NCs) and explore electrocatalytic hydrogen evolution performance. Theoretical calculations indicate that phosphorus introduction into CoS2shifts the d-band of Co atom towards the Fermi surface, making the surface activation barrier of CoPS (0.98 eV) far lower than that of CoS2(1.41 eV). By growing the rod-like Co3(PO4)2with surface decoration of CoPS NCs on the CoS2wrapped carbon fiber paper as electrochemical cathode, we show that such a composite structure can effectively improve the escape efficiency of H2due to large specific surface area. The current density reaches 10 mA cm−2at 47 mV. The tafel slope is only 52 mV dec−1, which is far smaller than that of CoS2. Spectroscopic characterization suggests that the modified electronic states of CoPS NCs and good charge transport kinetics in the compound are responsible for the observed high-efficiency HER performance. This study provides a useful strategy for designing and fabricating efficient electrocatalysts with synergistic effect of double anions and hierarchical activity.