Highly conductive and metallic cobalt–nickel selenide nanorods supported on Ni foam as an efficient electrocatalyst for alkaline water splitting. Issue 16 (10th April 2019)

• Record Type: Journal Article
• Authors: Liu, Shu; Jiang, Yimin; Yang, Miao; Zhang, Mengjie; Guo, Qifei; Shen, Wei; He, Rongxing; Li, Ming
• Is Part Of: Nanoscale. Volume 11:Issue 16(2019)
• Page Start: 7959
• Page End: 7966
• Publication Date: 2019-04-10
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c8nr10545f
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : Co0.75 Ni0.25 Se/NF for overall water splitting. Abstract : Water splitting has long been considered as a promising chemical reaction that can produce clean hydrogen fuel to relieve the energy crisis and environmental pollution. Herein, we report that Co0.75 Ni0.25 Se/NF formed by two-step growth of metallic cobalt–nickel selenide nanorods on porous nickel foam was used as a bifunctional electrocatalyst. Ni foam serves as a slow-releasing nickel source together with a Co source to form a special proportional cobalt–nickel selenide. Due to its unique rough nanostructure, bimetallic cooperative effects and intrinsic metallic character, the obtained Co0.75 Ni0.25 Se/NF electrode exhibits a low overpotential of 269 mV (50 mA cm −2 ) for the oxygen evolution reaction and an overpotential of 106 mV (10 mA cm −2 ) for the hydrogen evolution reaction. Furthermore, this bifunctional electrocatalyst requires a cell voltage of 1.60 V to achieve a current density of 10 mA cm −2 . Besides, based on theoretical calculation, it is further shown that the synergy between Co and Ni elements is beneficial for improving the internal structure of the catalyst, resulting in a high electrical conductivity, and low HER Gibbs free-energy and water adsorption energy. The present results indicate that Co0.75 Ni0.25 Se/NF exhibits advanced electrocatalytic activity for overall water splitting. This work offers an appropriate methodology and theoretical guidance to synthesize a bimetal–selenide electrocatalyst for water splitting.