Core-shell g-C3N4@ZnO composites as photoanodes with double synergistic effects for enhanced visible-light photoelectrocatalytic activities

Abstract

In this work, core-shell g-C3N4@ZnO photocatalysts were facilely synthesized via a reflux method applying the industrial grade ZnO nanoparticles and g-C3N4 nanosheets as the starting materials. The thickness of the g-C3N4 shell was gradually increased with the increasing proportion of g-C3N4 and the average thickness of the coating g-C3N4 is 1.89nm and 3.21nm for a weight ratio of 15% and 20% (g-C3N4/ZnO) g-C3N4@ZnO composites, respectively. By using g-C3N4@ZnO composites as photoanodes for the first time, 15% g-C3N4@ZnO photoanode exhibits the best PEC performance for the degradation of phenol under visible light irradiation with an anodic bias of 1.5V vs. SCE and the rate constant is determined to be 1.216h−1, which is almost 2.1 times as high as that of 20% g-C3N4@ZnO photoanode. The enhancement of the visible light PEC degradation phenol is attributed to the double synergistic effects which combined of special core-shell nanostructures and electro-oxidation assisted photocatalysis. This work not only demonstrates core-shell g-C3N4@ZnO composites as a promising photoanode for the utilization of solar conversion, but also meets the requirement for the increasing demand of practical applications