Markedly enhanced visible-light photocatalytic H2 generation over g-C3N4 nanosheets decorated by robust nickel phosphide (Ni12P5) cocatalysts

Abstract

In the present work, nickel phosphide (Ni₁₂P₅) modified graphitic carbon nitride (g-C₃N₄) nanosheets were synthesized by a simple grinding method. The structural characterization clearly proved that Ni₁₂P₅ nanoparticles were well loaded on the surface of g-C₃N₄ nanosheets. The photocatalytic activity of the composites was tested by catalyzing the reduction of water to hydrogen under visible light irradiation. The results demonstrate that Ni₁₂P₅ is an efficient co-catalyst for photocatalytic H₂ production of g-C₃N₄ nanosheets. The maximum photocatalytic H₂-production rate of 126.61 μmol g⁻¹ h⁻¹ could be obtained by loading 2.0% Ni₁₂P₅ nanoparticles on the surface of g-C₃N₄, which is about 269.4 times higher than that of pure g-C₃N₄. It is believed that Ni₁₂P₅ nanoparticles on the surface of g-C₃N₄ could act as significant active sites to boost separation of photoexcited electrons and holes and accelerate the H₂-evolution kinetics, thus achieving greatly enhanced hydrogen generation. It is expected that this work could contribute to further experimental investigation for exploiting the low cost, high-efficiency, and environmentally friendly g-C₃N₄-based nanocomposites for photocatalytic H₂ production.