Enhanced Hydrogen Evolution Performance of Carbon Nitride Using Transition Metal and Boron Co-Dopants

Density functional theory calculations are used to study the effect of several metal dopants (M = Ag, Cd, Co, Cu, Fe, Ni, Pt, Sc, Ti, and Zn) and metal–boron co-dopants on the structure and catalytic property of g-C₃N₄ 2D monolayer. Using transition metals and boron (TM–B) as co-dopants not only keeps the 2D structure stability of g-C₃N₄ monolayer, but also alters the catalytic performance of the structures. The co-doping of B in TM (TM = Pt, Zn, Cd, Ti, and Sc)-doped g-C₃N₄ leads to a significant increase in the hydrogen adsorption energy because hydrogen binding site changes from N to C. For TM–B (TM = Fe, Co, and Ni) co-doped g-C₃N₄, the hydrogen adsorption energy has no obvious change since the hydrogen binding site remains on C atom near the doped TM. However, the co-doping of B in TM- (TM = Cu and Ag) doped g-C₃N₄ leads to a significant reduction of hydrogen adsorption energy, making them good candidates for hydrogen evolution reaction. This study provides theoretical guidance for the experimental synthesis of TM–B co-doped g-C₃N₄ and paves a way for the design of a widely applicable non-noble catalyst.