Sacrificial agent-free photocatalytic H2O2 evolution via two-electron oxygen reduction using a ternary α-Fe2O3/CQD@g-C3N4 photocatalyst with broad-spectrum response. Issue 36 (1st September 2020)

• Record Type: Journal Article
• Authors: Chen, Xi; Zhang, Wenwen; Zhang, Lixiang; Feng, Luping; Zhang, Chunxian; Jiang, Jie; Yan, Tingjiang; Wang, Hua
• Is Part Of: Journal of materials chemistry. Volume 8:Issue 36(2020)
• Page Start: 18816
• Page End: 18825
• Publication Date: 2020-09-01
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d0ta05753c
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : The developed α-Fe2 O3 /CQD@g-C3 N4 can perform a direct one-step two-electron reduction for efficient photocatalytic H2 O2 ; evolution in pure water. Abstract : Ultrathin g-C3 N4 nanosheets have been fabricated via a two-step calcination regulated by melamine precursors at a high heating rate (30 °C min −1 ). The resulting g-C3 N4 nanosheets were further employed as carriers for the growth of carbon quantum dots (CQDs) and (110) exposed α-Fe2 O3 through the PVP-enabled adsorption effects by a solvothermal process. It was discovered that the so fabricated ternary photocatalyst α-Fe2 O3 /CQD@g-C3 N4 presented a broad-spectrum absorption range (up to 800 nm) and particularly enhanced active sites of photogenerated electrons for highly efficient photocatalytic oxygen reduction toward H2 O2 evolution in pure water. A H2 O2 production rate of 1.16 μM min −1 could be expected for the developed photocatalyst under visible light irradiation, which is about 19 times faster than that of pure ultrathin g-C3 N4 . Herein, the loaded Fe2 O3 could transform the H2 O2 evolution from two-step single-electron reduction into one-step two-electron one, as verified by the various active species experiments and rotating ring-disk electrode tests. This work presents a new perspective in designing ultrathin g-C3 N4 through a simple method of precursor-regulated calcination, which features more outstanding advantages than the conventional exfoliation of bulk g-C3 N4 towards ultrathin g-C3 N4 . More importantly, it provides an optimized photocatalytic reaction route of two-electron oxygen reduction for efficient H2 O2 production in pure water under visible light irradiation, without the need for noble metals or organic sacrificial agents.