Fe‐Doped Porous g‐C 3 N 4 : An Efficient Electrocatalyst with Fe‐N Active Sites for Electrocatalytic Hydrogen Evolution Reaction under Alkaline Conditions

Abstract Herein, Fe‐C 3 N 4 ‐TU was prepared by one‐step pyrolysis of melamine (MA, carbon and nitrogen sources of g‐C 3 N 4 ) and Fe(NO 3 ) 3 ⋅ 9H 2 O using thiourea (TU) as a pore‐forming agent. Fe‐C 3 N 4 ‐TU exhibits a low Tafel slope of 82 mV ⋅ dec −1 and a low overpotential of 206 mV at the current density of 10 mA ⋅ cm −2 . The good HER (Electrocatalytic hydrogen evolution reaction) catalytic performance of Fe‐C 3 N 4 ‐TU is attributed to the high intrinsic activity of Fe−N(III) coordination structure and porous structure with the intersecting channels. The Fe−N(III) coordination structure is proved by the characterized results of the XRD, XPS, and FTIR, which originates from the strong affinity of rich pyridine N in the g‐C 3 N 4 to Fe ions. Simultaneously, the addition of TU as a pore‐forming agent induces the formation of large specific surface area and mesoporous structures with large pore diameters, which facilitate the exposure of Fe−N bonds and promotes H adsorption in the HER process.