Efficient day-night photocatalysis performance of 2D/2D Ti3C2/Porous g-C3N4 nanolayers composite and its application in the degradation of organic pollutants

It is hindered by the limited light time that the development of photocatalysis technology, which is a clean and energy-saving advanced oxidation process. In this work, a 2D/2D Ti3C2/porous g-C3N4 nanolayers composited van der Waals (VDW) heterostructure photocatalyst (Ti3C2/PCN) was prepared by a straightforward vacuum filtration method after an ultrasonic stripping process. In this Ti3C2/PCN composite photocatalyst, PCN nanolayers play the role of absorbing visible light, while Ti3C2 nano-layers form VDW heterojunction with PCN nanolayers, which is beneficial to migration of photo-generated electrons from PCN to Ti3C2. The band structure match of Ti3C2/PCN and the build-in electric field from the VDW heterojunction both favor the effective separation and migration of photo-induced charge carriers that is why the Ti3C2/PCN composite shows good day-photocatalytic capability with 98% phenol removal efficiency. Besides, as a good electronic storage material, the Ti3C2 can store excess photo-generated electrons under light irradiation and release them when exposed to electron acceptors in the dark condition. Therefore, the night-photocatalysis can work out even without sunlight, in which 32% phenol was decomposed. In addition, the universality of Ti3C2/PCN day-night photocatalytic system is proved by the degradation of various organic pollutants. The design of this day-night photocatalyst can facilitate the application of photocatalytic reaction to actual environmental scenes, since it reduces the limitation imposed by the presence or absence of sunlight. (C) 2019 Elsevier Ltd. All rights reserved.