Making MetalCarbon Nitride Heterojunctions for Improved Photocatalytic Hydrogen Evolution with Visible Light

Abstract Gold nanoparticles were deposited on the surface of a g‐C 3 N 4 semiconductor by deposition–precipitation, photodeposition, and impregnation methods to make metal–semiconductor junctions for photocatalytic hydrogen evolution from aqueous solution containing an electron donor with visible light illumination. The samples were characterized by X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), UV/Vis, and transmission electron microscopy (TEM). Results show that the Au/g‐C 3 N 4 prepared by the deposition–precipitation method possessed the best photocatalytic activity, due to the formation of tight Au–semiconductor heterojunctions effectively promoting the transfer of charge from light‐excited g‐C 3 N 4. Surface modification of the Au/g‐C 3 N 4 with a second metal further improved the activity of the photocatalytic system, which was explained by simultaneous optimization of electron transfer by the gold and chemical reactivity by the secondary metal.