Two–dimensional g–C3N4/α–AgAl0.4Ga0.6O2 p–n heterostructure with improved visible–light–driven photocatalytic property

Abstract Design and preparation of two–dimensional heterostructure is an effective strategy to obtain enhanced photoelectrochemical and photocatalytic performances. Herein, two–dimensional g–C3N4/α–AgAl0.4Ga0.6O2 p–n heterostructure is for the first time synthesized by phase transition method under hydrothermal treatment. It is found that the heterostructure shows the coexistence of two phases with high crystallinity. Platelet-like α–AgAl0.4Ga0.6O2 and g–C3N4 sheets couple each other face to face, resulting in the formation of close interfaces and efficient heterojunctions. UV–vis absorption of the heterostructure is modulated efficiently by controlling the phase component. When utilized as photocatalysts for MO degradation under visible light irradiation, the g–C3N4/α–AgAl0.4Ga0.6O2 with a molar ratio of 0.75 exhibits the most excellent photocatalytic performance with a rate constant of 0.0227 min−1. The further investigation of the photoelectrochemical property including small diameter of the arc radius and maximum photocurrent indicates that the separation efficiency of electron–hole pairs is greatly improved through heterojunctions with two–dimensional coupling interfaces. Besides, the reaction kinetics and the photocatalytic mechanism related to the energy band are proposed for degrading organic pollutants. The results prove that the g–C3N4/α–AgAl0.4Ga0.6O2 heterostructure has great potential application in photocatalysis for eliminating organic pollutants.