Synthesis of 0D SnO2 nanoparticles/2D g-C3N4 nanosheets heterojunction: improved charge transfer and separation for visible-light photocatalytic performance

A novel 0D SnO2 nanoparticles/2D g-C3N4 nanosheets heterojunction has been successfully constructed by electrostatic self-assembly. The 2D g-C3N4 nanosheets (CNNSs) are prepared by multiple thermal exfoliation at 500 degrees C, and 0D SnO2 nanoparticles (NPs) with the average diameter of about 30 nm are prepared by hydrothermal method. The experiment and calculation results have revealed that a built-in electric field (BIEF) has been established at the contact interface of SnO2/CNNSs type II heterojunction, and this BIEF can specify charge transfer direction and promote charge separation. Furthermore, the raised conduction band (CB) of CNNSs provides a greater driving force for the charge transfer from CNNSs to SnO2. SnO2/CNNSs heterojunction exhibits the highest degradation of 96.9% for Rhodamine B (RhB) within 50 min under simulated visible light, which is 32.3 and 1.5 times than that of SnO2 and CNNSs, respectively. The superoxide radical (center dot O2-)is confirmed as the most important active substance in photocatalytic activity and a possible photocatalytic mechanism of SnO2/CNNSs has been proposed for the improved photocatalytic performance. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

An efficient 0D SnO2 nanoparticles/2D g-C3N4 nanosheets heterojunction was successfully constructed by electrostatic self-assembly for high-performance photocatalytic degradation of Rhodamine B. The heterojunction established a built-in electric field to promote charge separation, increasing electron transfer efficiency, and utilizing photocatalysis for organic dye degradation.