Nanoporous CoP nanowire arrays decorated with carbon‐coated CoP nanoparticles: the role of interfacial engineering for efficient overall water splitting

The innovative construction of bifunctional non-noble electrocatalyst for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is imperative for electrochemical water splitting. Herein, we provide a collaborative self-templating method to prepare a hybrid catalyst of nanoporous CoP nanowire (NWs) arrays decorated with carbon-coated CoP nanoparticles (NPs). It's found that the unique structure and morphology of the resultant catalyst can provide abundant available active sites and faciliatate the rapid H2/O2 transmission. Additionally, the N-doped carbon improves the conductivity of the catalyst and prevents the aggregation and deactivation of CoP nanoparticles. Forthermore, the strong coupling and synergistic effects by interface engineering are also conducive to the electrochemical performance. Benefiting from these advantages, the CoP NWs/CoP NPs@NC/CC only needs a low overpotential of 103 mV to achieve 10 mA cm−2 with a small Tafel slope of 87 mV dec−1 for HER. When employed in an electrolytic cell as an electrocatalyst for overall water splitting, a low voltage of 1.60 V is required to drive 10 mA cm−2. This study may provide a novel way to fabricate transitionmetal-based catalysts for water splitting.