The Mo as electron trapper and donor to modulate the electron of CoP2 in phosphating process

To prepare bifunctional electrocatalyst towards HER and OER is extremely important for promoting the development of electrochemical water splitting technology. Herein, the element doping method is employed to tune the electron environment of cobalt phosphide (CoP). The Mo-doped CoP supported on carbon cloth (CC) is constructed by solvothermal and annealing method. The effect of Mo on the electron modulation of CoP during different phosphating time was studied carefully. It is noted that the Mo play an important role in tuning the electron state of Co and P elements which can trap the electron and was reduced to low valence, then transfer the electron to Co and P. With increasing the phosphating time, the electron transfer phenomenon between Mo and CoP is obvious. Benefiting from the electron engineering of Mo, Co and P as well as thin and wrinkle sheets structure, the optimal electrocatalyst only requires 39 mV and 251 mV to deliver 10 mA cm-2 for HER and OER, respectively. Also, as for the whole water splitting performance, it delivers 10 mA cm-2 at cell voltage of 1.56 V. Importantly, Faraday efficiency of the optimal catalyst achieves 99.9% for HER due to the tuned electron state of Co and P, high ECSA and low Rct.(c) 2022 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

Preparing bifunctional electrocatalysts for HER and OER is crucial for the development of electrochemical water splitting technology. In this study, the electron environment of cobalt phosphide (CoP) is tuned using the element doping method, and Mo-doped CoP supported on carbon cloth (CC) is constructed. The effect of Mo on the electron modulation of CoP is carefully studied, and it is found that Mo plays a key role in tuning the electron state of Co and P elements. The optimized electrocatalyst exhibits excellent performance for HER and OER, with low overpotentials and high Faraday efficiency due to the electron engineering of Mo, Co, and P as well as its unique structure.