A robust hydrogen evolution catalyst based on crystalline nickel phosphide nanoflakes on three-dimensional graphene/nickel foam: high performance for electrocatalytic hydrogen production from pH 0-14

The design and preparation of highly active catalysts for the hydrogen evolution reaction (HER) is very important for water splitting. Herein, we report a highly active HER catalyst, which is synthesized by loading nanostructured nickel phosphide (Ni2P) on three-dimensional few-layer graphene/nickel foam (G@NF). G@NF was successfully prepared by a chemical vapor deposition process in the presence of methane at high temperature. Compared with nickel phosphide, G@NF, as well as commercial platinum, the Ni2P-G@NF catalyst exhibited very high activity in electrocatalytic H-2 production from water (similar to 7 mV over-potential in alkaline solutions, pH similar to 14; and similar to 30 mV overpotential in acidic solutions, pH similar to 0). The high catalytic activity of Ni2P-G@NF is attributed to the excellent performance of Ni2P, the large 3D framework which facilitates proton accessibility and electron transfer, and the high surface area.