In-situ phosphatizing of cobalt-molybdenum nanosheet arrays on self-supporting rGO/CNTs film as efficient electrocatalysts for hydrogen evolution reaction

Although great progress has been made in the area of electrocatalysis, the design of earth-rich and efficient electrocatalysts remains a major challenge. It is of great significance to explore non-noble metal-based electrocatalysts with efficient and stable performance for hydrogen evolution reaction (HER) in the relatively wide pH range. Herein, a self-supporting three-dimensional (3D) CoMoP-rGO/CNT catalyst was synthesized to achieve high efficiency of HER in acidic and basic solution. The combination of CNTs and rGO improves the conductivity of the substrate material, while the self-supporting structure avoids the use of the binder to expose the active sites, and the open structure of the vertically arranged CoMoP nanosheet arrays is benefit for the interaction between the electrolyte and the active sites. Thus, the CoMoP-rGO/CNT showed excellent activity and durability for HER with a low overpotential of 66 mV and 86 mV at a current density of −10 mA·cm−2 in acidic (0.5 M H2SO4) and basic (1 M KOH) solution, respectively. The three-dimensional structure of CoMoP-rGO/CNT can enhance electron migration and mass transfer, while Co and Mo also play an important role in regulating surface active sites. This work may open a new way for the design of earth-rich and low-cost nanomaterials for electrocatalysis.