Facile synthesis of g-C3N4/BiOClxI1-x hybrids with efficient charge separation for visible-light photocatalysis

Abstract At present, most common catalysts are faced with the problem of high cost and only visible light response. Graphitic carbon nitride (g-C3N4) consists of elements C and N that are sufficiently abundant in the world and has visible light responses, but the electron-hole recombination rate of this photocatalyst is high. In this work, we directly prepare a series of g-C3N4-bismuth oxyhalides composites via facile in-situ deposition. Bismuth oxides with different chloro-iodine ratios (BiOClxI1-x) are prepared, followed by g-C3N4 deposition, setting up interfaces and improving photogenic charge carriers transfer. By testing the compositions, Cl:I = 8:2 in BiOClxI1-x and 10% of g-C3N4 doping amount enable the best photocatalytic performance of the samples. Under visible light irradiation, the degradation rate of rhodamine B (RhB) reaches 99% within 40 min. Through a variety of tests, the photogenerated hole (h+) and superoxide radical (•O2−) are found to play key roles in the degradation process. Cl element doping and heterojunction building improve the photocatalysis capacity of g-C3N4 and broaden the visible-light response of pure BiOI.