Multi-walled carbon nanotubes reinforced nickel phosphide composite: As an efficient electrocatalyst for hydrogen evolution reaction by one-step powder sintering

Transition metal phosphides (TMPs) have been proven to be a high-performance non-noble metal electrocatalyst with high activity and nearly similar to 100% Faraday efficiency. However, their applications remain faces great challenging due to its unsatisfactory exposure to catalytic active sites and electronic conductivity. Here, powder sintering was used to prepare Ni-P-Multi-walled carbon nanotubes (Ni-P-MWCNTs) composite electrodes with a hierarchical flower-like structure with a large surface area, the composite electrodes were synthesized by phosphating mixed powder (porous nickel powder, red phosphorus and MWCNTs). Due to the flower-like nanoplate hierarchical structure, the fast vectorial electron transfer along the building block nanoplates was effectively induced and active sites were highly exposed. The resulting Ni-P-43 wt%MWCNTs shows high activity and durability towards the Hydrogen evolution reaction (HER) under acidic conditions. It demands extremely low onset-potential of 29 mV, 96 mV to achieve a current density of 10 mA cm(-2). This work suggests an effective method to facilitate grain preferred orientation growth and exposure high activity active, experimental results demonstrate that the electrocatalytic performance of as-prepared Ni-P-MWCNTs were successfully optimized through the addition of MWCNTs, and might promote further study of the TMPs catalysts for HER. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.