High-performance CoNb phosphide water splitting electrocatalyst on plasma-defect-engineered carbon cloth

Abstract

Herein, an efficient and stable Co-Nb bimetallic phosphide electrocatalyst for HER is successfully engineered on the dielectric barrier discharge (DBD) plasma modified carbon cloth (PCC) at ambient conditions. The resulting microsized drum-like CoP3-Nb2P catalysts supported by the PCC show high electrocatalytic activity, which only needs overpotentials of 111, 317 and 375 mV to generate current densities of 10, 500 and 1000 mA cm−2 (j10, j500 and j1000) respectively. A small Tafel value of 72.8 mV dec−1 is achieved. When the current density is over j202, the performance of the CoP3-Nb2P/PCC surpasses commercial noble metal-based Pt/C/PCC catalysts. The current density drops only 6.4 % after 50 h I-t testing at j100, indicating a good electrochemical stability. Theory calculations and in-situ Raman spectra results reveal the synergistic effect between Co and Nb phosphide causes a remarkable HER performance, and the Nb-Nb vibration weakens the P-Hads bond, leading to the effective H2 generation.