Electrodeposition, formation mechanism, and electrocatalytic performance of Co-Ni-P ternary catalysts coated on carbon fiber paper

Transition metal-based catalysts are considered to be promising materials to replace noble metal catalysts for electrocatalytic water splitting. Herein, a flexible electrode composed of Co-Ni-P ternary catalysts and carbon fiber paper substrate (Co-Ni-P/CFP) was successfully fabricated and applied in water electrolysis. The Co-Ni-P coatings were deposited on CFP by a one-step cyclic voltammetric electrodeposition method and the surface of the composite material exhibits nano-reticular structure. The formation mechanism was also discussed according to the results of material characterization. Notably, the Co-Ni-P/CFP flexible electrode exhibited superior catalytic performance for both hydrogen and oxygen evolution reactions in alkaline media, which could achieve 10 mA/cm(2) current density with overpotential of 89 mV for HER and 320 mV for OER. Moreover, the Co-Ni-P/CFP electrode could also be used as both anode and cathode electrode to drive overall water splitting and required only 1.64 V to achieve a current density of 10 mA/cm(2), which was very close to that of the commercial combination of Pt/C and IrO2. This affordable and easily obtained electrode offers a new avenue to develop earth-abundant resource catalysts for water electrolysis system.

Automated summary

A flexible electrode composed of Co-Ni-P ternary catalysts and carbon fiber paper substrate was successfully fabricated and exhibited superior catalytic performance for both hydrogen and oxygen evolution reactions in alkaline media. This electrode could achieve a current density of 10 mA/cm(2) with overpotentials of 89 mV for HER and 320 mV for OER, showing great potential for water electrolysis applications. The electrode could also be used as both anode and cathode electrode to drive overall water splitting, requiring only 1.64 V to achieve a current density of 10 mA/cm(2), which is close to the performance of commercial Pt/C and IrO2 combinations.