g-C₃N₄/Pt/BiVO₄ nanocomposites for highly efficient visible-light photocatalytic removal of contaminants and hydrogen generation

Inspired by natural photosynthesis, artificial heterojunction photocatalysts have been extensively studied. Herein, a novel ternary graphitic carbon nitride/platinum/bismuth vanadate (g-C₃N₄/Pt/BiVO₄) photocatalytic system was successfully synthesized, where Pt/BiVO₄ nanosheet is anchored on the surface of layered g-C₃N₄, as evidenced by structural observations. Ultraviolet photoelectron spectroscopy and ultraviolet–visible diffuse reflectance spectroscopy are carried out to identify the position of the conduction band and valence band. A Z-scheme is used to interpret the superior photocatalytic performance of g-C₃N₄/Pt/BiVO₄ and further verified by the capture of free radicals and terephthalic acid photoluminescence experiments. Compared with the g-C₃N₄/BiVO₄ binary system, the Z-scheme g-C₃N₄/Pt/BiVO₄ photocatalyst not only possesses enhanced carrier separation efficiency but also maintains sufficient redox properties, thus inducing superior photocatalytic activity. More importantly, the novel Z-scheme photocatalyst exhibits excellent recycle stability, which could provide inspiration for the rational design of efficient and practical photocatalysts for environmental pollution treatment. The ternary photocatalyst also exhibits significantly enhanced visible-light photocatalytic hydrogen production performance. (paper)