Hierarchical NiMo Phosphide Nanosheets Strongly Anchored on Carbon Nanotubes as Robust Electrocatalysts for Overall Water Splitting

Although a great achievement has been made in the field of electrochemistry, the exploration of high-efficiency catalysts for the generation of hydrogen and oxygen via overall water splitting is still a grand challenge. We herein report the successful construction of a new class of hierarchical catalysts with defect-enriched nickel-molybdenum phosphide nanosheets anchored on the surface of carbon nanotubes for efficient water splitting. Via the construction of a hierarchical nanostructure, more efficient electron mobility and mass transfer occurrence were achieved, resulting in a substantial enhancement of electrocatalytic performances. Interestingly, overpotentials of only 255 and 135 mV are required for the optimized Ni₁Mo₁P NSs@MCNTs to afford a current of 10 mA cm^-2 for oxygen evolution reaction and hydrogen evolution reaction, respectively. More significantly, the introduction of molybdenum and phosphorus is also significant for exposing surface active sites and modifying the bonding energy between hydrogen and metals; all of these advantages have endowed the Ni₁Mo₁P NSs@MCNTs//Ni₁Mo₁P NSs@MCNTs couple to display highly efficient water electrocatalysis property with a relatively low overall potential of 1.601 V at 10 mA cm^-2, shedding bright light for large-scale overall water electrocatalysis.