La-Doped ZnO/g-C3N4 Heterojunction for Efficient Degradation of Organic Contamination Under Visible Light Irradiation

Considering the accelerated charge/mass transfer and the formation of active defects at the heterointerface, La-ZnO/g-C 3 N 4 heterogeneous photocatalysts were facilely prepared via a two-step route consisting of hydrothermal and calcination processes in this work. The combination of La 3+ doping in ZnO and the contact between La-ZnO and g-C 3 N 4 endowed the heterogeneous composite with a much enhanced photocatalytic activity towards methyl blue (MB) dye decolorization under the visible light irradiation. It was found that La-ZnO/g-C 3 N 4 -4.6 showed an optimal degradation rate of MB (8.72 × 10 − 2 min − 1 ), which is 14 times higher than that of pure g-C 3 N 4 (6.23 × 10 − 3 min − 1 ) under the same experimental conditions. The improved photocatalytic MB decolorization is attributed to the increased interfacial electron-hole separation efficiency through constructing La-ZnO/g-C 3 N 4 heterogeneous interfaces. The present study manifests the advantage of heterogeneous interfaces as the charge carrier separation pathway towards boosting photocatalytic activity.