“Nanoregion” effect of ionic liquid mixture system for preparing highly active porous electrocatalytic hydrogen production materials

Abstract

The development of porous electrocatalytic materials with high activity and large specific surface area is the key to realizing efficient hydrogen production by water electrolysis. In this paper, a universial strategy for preparing porous non-precious metal electrocatalysts with high effective surface area is provided based on the “nanoregion” formed by ionic liquid mixture system, and the feasibility is verified by constructing a porous NiCo@NC based electrocatalyst. The microstructure, surface composition, specific surface area and electrochemical properties of the porous electrocatalyst are investigated systematically. Compared with the traditional hydrothermal synthesis, the “nanoregion” effect can give the NiCo@NC electrocatalyst rich pore structure and good hydrophilicity, thus effectively improve the effective surface area available for the electrochemical reaction. As a result, the overpotential for HER on NiCo@NC-500 prepared in the ionic liquid mixing system is 113 mV lower than that on NiCo@NC-500-w prepared by common hydrothermal process, and the Tafel slope decreases by 37 mV dec⁻¹ (33.9 %), further verifying the effectiveness of this simple and green strategy to develop porous non-precious metal electrocatalysts for hydrogen production by the “nanoregion” effect of ionic liquid mixture system.