Facile synthesis of nickel cobalt selenide hollow nanospheres as efficient bifunctional electrocatalyst for rechargeable Zn-air battery

Abstract

Designing high active, low cost and bifunctional electrocatalysts is urgent for developing clean energy storage and conversion systems. Transition metal selenides exhibit optimal electronic conductivity and tunable physicochemical properties, which endow them with potential for efficient electrocatalysts to facilitate the oxygen reduction and oxygen evolution reactions (ORR and OER). Herein, hollow Ni x Co 0.85- x Se nanospheres were synthesized using a facile polyol based solution chemical method. The Ni x Co 0.85- x Se exhibits an onset overpotential of 0.89 V for ORR, and an overpotential of 305 mV to achieve 10 mA cm −2 for OER. Moreover, the Ni x Co 0.85- x Se based Zn-air battery displays remarkable specific capacity and durability. Such superior catalytic performances can be attributed to the synergistic effect, large specific surface area and enhanced electron transfer rate. This approach provides a new way to design highly efficient bifunctional electrocatalysts for electrochemical energy storage and utilization. 合成高活性、 低成本、 双功能特性的电催化剂是目前发展新能源材料的重要任务. 过渡金属硒化物具有较高的电导特性、 可调节的物理化学特性等, 成为了开发高效氧还原和氧析出催化剂的研究热点. 本文采用多元醇溶液化学法合成了具有较大比表面积的Ni x Co 0.85- x Se中空纳米球. 该催化剂的ORR起始电位达到0.89 V, OER在10 mA cm −2 电流密度下的过电位达到305 mV. 以Ni x Co 0.85− x Se中空纳米球为空气电极、 锌片为阴极组成的锌空电池具有良好的比容量和循环稳定性. Ni x Co 0.85− x Se中空纳米球优异的催化性能主要归因于较大的比表面积、 Ni和Co的协同催化特性以及良好的导电性. 本文为设计高效的锌空电池催化剂提供了良好的理论基础和实验支持.