Abstract
The strategic design and fabrication of efficient electrocatalysts are pivotal for advancing the field of electrochemical water splitting (EWS). To enhance EWS performance, integrating non-noble transition metal catalysts through a cooperative double metal incorporation strategy is important and offers a compelling alternative to conventional precious metal-based materials. This study introduces a novel, straightforward, single-step process for fabricating a bimetallic MoCo catalyst integrated within a three-dimensional (3D) nanoporous network of N, P-doped carbon nitride derived from a self-contained precursor. The subsequent carbonization at 550 °C yields a highly effective bimetallic phosphide carbon nitride electrocatalyst, denoted as MoCoPCN, tailored explicitly for EWS. The MoCoPCN electrocatalyst demonstrates exceptional electrocatalytic performance, with a low onset potential of 1.43 V and an overpotential value of 202 mV at a current density of 10 mA/cm2 for the oxygen evolution reaction (OER) and 49.5 mV for the hydrogen evolution reaction (HER), respectively. Moreover, the catalyst exhibits a high electrochemically active surface area of 2720 cm–2, a small Tafel slope of 47.5 mV dec–1 for HER and 45.7 mV dec–1 for the OER, and a low charge transfer resistance of 0.09 Ω for the HER and 0.805 Ω for the OER. The optimal catalyst was tested for overall water splitting performance in a 1 M KOH electrolyte, demonstrating excellent efficiency with a low cell voltage of 1.49 V required to achieve a current density of 10 mA/cm2. These outstanding characteristics, combined with the synergistic effects arising from the interaction between MoCo and P-g-C3N4 (PCN), underscore the potential of a bimetallic phosphide carbon nitride material as a highly promising electrocatalyst for efficient water splitting.
