Few layer g-C₃N₄ decorated flower-like ZnO for visible light photocatalytic reduction of Cr(VI)

Semiconductor heterojunction nanostructures have drawn attention due to their novel structures, unique electrical and optical properties. Herein, we reported a facile vapor deposition process to construct a few layer g-C₃N₄/flower-like ZnO heterojunction. The structure and morphology of heterojunction were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, UV–vis diffuse reflectance spectroscopy and photoluminescence spectra. The results showed that few layer g-C₃N₄ was deposited on the surface of flower-like ZnO to form the close interaction. The reduction of Cr(VI) under visible light irradiation was used to evaluate the activity of photocatalyst. The heterojunction exhibited enhanced photocatalytic activity, which could result in 95% of Cr(VI) reduction within 120 min. The trapping experiments verified that photoelectrons played a main role in the Cr(VI) reduction process.