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

• Published in: Journal of alloys and compounds 2021-08, Vol.871, p.159561, Article 159561
• Main Authors: Sun, Chaoyang, Yang, Jingkai, Zhu, Yan, Xu, Min, Cui, Yan, Liu, Lu, Ren, Wangwei, Zhao, Hongli, Liang, Bo
• Format: Article
• Language: English
• Subjects: 0D SnO2 NPs/2D CNNSs; Built-in electric field; Carbon nitride; Catalytic activity; Charge separation; Charge transfer; Conduction bands; Electric contacts; Electric fields; Electron transfer; Heterojunctions; Nanoparticles; Nanosheets; Photocatalysis; Photocatalytic performance; Rhodamine; Self-assembly; Separation; Tin dioxide
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2021.159561

•Constructed 0D SnO2 nanoparticles/2D g-C3N4 nanosheets heterojunction by electrostatic self-assembly.•Built-in electric field and band re-adjustment promoted charge transfer and separation.•Theoretical calculations and experiments proved type II band arrangement structure.•Demonstrated excellent visible-light photocatalytic performance. [Display omitted] 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 °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 (•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.