Self-contained P, C and N-Mediated Bifunctional MoCo Phosphide Carbon Nitride Electrocatalyst for Water Electrolysis

Abstract

The strategic design and fabrication of efficient electrocatalysts holds pivotal importance in advancing the field of electrochemical water splitting (EWS). A promising way to boost EWS performance lies in the integration of non-noble transition metal catalysts via a cooperative double metal incorporation strategy, offering a compelling alternative to conventional Pt based materials. In this study, we introduce an innovative and straightforward single-step process to fabricate bimetallic MoCo catalyst integrated within a three-dimensional (3D) nanoporous thin network of self-sufficient heteroatoms N,P-doped carbon nitride. Subsequent carbonization at 550 °C yields a highly effective bimetallic phosphide carbon nitride electrocatalyst, denoted as CoMoPCN, tailored specifically for EWS. Comprehensive characterization employing XRD, FT-IR, XPS, TEM, HR-TEM, and HAADF EDS mapping confirms the structural integrity and composition of the synthesized catalyst. The engineered electrocatalyst demonstrates exceptional electrocatalytic performance, showing the lowest onset potential of 1.43 V, along with overpotential values of 212 mV and 49.5 mV at a current density of 10 mA/cm2 for the Oxygen Evolution Reaction (OER) and Hydrogen Evolution Reaction (HER), respectively. Moreover, the catalyst exhibits an increased electrochemically active surface area (ECSA) determining 2720 cm-2 , leading to the smallest Tafel slope and the lowest charge transfer resistance. These outstanding characteristics, coupled with the synergistic effects arising from the interaction between MoCo and P-gC3N4 (PCN), collectively contribute to a significantly enhanced electrocatalytic performance in both OER and HER. These findings show the effectiveness of the synthesized bimetallic phosphide carbon nitride as a highly promising electrocatalyst for efficient OER and HER applications.