Enhanced OER Performances of Au@NiCo2S4 Core-Shell Heterostructure
Enhanced OER Performances of Au@NiCo2S4 Core-Shell Heterostructure
复制标题
Au@NiCo2S4核壳异质结构的增强OER性能
DOI：
10.3390/nano10040611
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发表时间：
2020-04-01
期刊：
影响因子：
5.3
通讯作者：
Wang, Rongming
中科院分区：
文献类型：
--
作者：
Lv, Yuepeng;Duan, Sibin;Wang, Rongming
过渡金属硫化物作为潜在的析氧催化剂备受关注。由于双金属阳离子之间的协同作用，双金属硫化物具有优异的物理化学性质。通过引入金属-半导体界面，可以进一步改善过渡金属硫化物的物理化学性质。采用溶剂热法制备了Au@NiCo2S4核壳异质结构纳米颗粒(NPs)和裸NiCo2S4纳米颗粒。OER催化性能测试表明，与裸NiCo2S4纳米粒子相比，Au@NiCo2S4核壳异质结构的催化活性有所提高。在电流密度为10 mA cm(-2)时，Au@NiCo2S4的过电位(299 MV)低于裸NiCo2S4的过电位(312 MV)。Au@NiCo2S4的Tafel斜率(44.5 mV dec(-1))较裸NiCo2S4(49.1 mV dec(-1))减小，表明其反应动力学较快。对其电子结构、化学状态和电化学阻抗的详细分析表明，裸露的Au@NiCo2S4核壳NPs的OER催化性能的提高是由于其高价Ni/Co离子比例的增加和电子电导率的增加。本工作为通过构建金属-半导体核壳异质结构来提高OER催化性能提供了一种可行的方法。
Transition metal sulfides have attracted a lot of attention as potential oxygen evolution reaction (OER) catalysts. Bimetallic sulfide possesses superior physicochemical properties due to the synergistic effect between bimetallic cations. By introducing a metal -semiconductor interface, the physicochemical properties of transition metal sulfide can be further improved. Using the solvothermal method, Au@NiCo2S4 core-shell heterostructure nanoparticles (NPs) and bare NiCo2S4 NPs were prepared. The measurement of the OER catalytic performance showed that the catalytic activity of Au@NiCo2S4 core-shell heterostructure was enhanced compared to bare NiCo2S4 NPs. At the current density of 10 mA cm(-2), the overpotential of Au@NiCo2S4 (299 mV) is lower than that of bare NiCo2S4 (312 mV). The Tafel slope of Au@NiCo2S4 (44.5 mV dec(-1)) was reduced compared to that of bare NiCo2S4 (49.1 mV dec(-1)), indicating its faster reaction kinetics. Detailed analysis of its electronic structure, chemical state, and electrochemical impedance indicates that the enhanced OER catalytic performances of bare Au@NiCo2S4 core-shell NPs were a result of its increased proportion of high-valance Ni/Co cations, and its increased electronic conductivity. This work provides a feasible method to improve OER catalytic performance by constructing a metal-semiconductor core-shell heterostructure.