Environmental application of chlorine-doped graphitic carbon nitride: Continuous solar-driven photocatalytic production of hydrogen peroxide

Mengqiao Li; Qinmin Zheng; David P Durkin; Hanning Chen; Danmeng Shuai

doi:10.1016/j.jhazmat.2022.129251

Environmental application of chlorine-doped graphitic carbon nitride: Continuous solar-driven photocatalytic production of hydrogen peroxide

J Hazard Mater. 2022 Aug 15:436:129251. doi: 10.1016/j.jhazmat.2022.129251. Epub 2022 May 30.

Authors

Mengqiao Li¹, Qinmin Zheng¹, David P Durkin², Hanning Chen³, Danmeng Shuai⁴

Affiliations

¹ Department of Civil and Environmental Engineering, The George Washington University, Washington, DC 20052 USA.
² Department of Chemistry, United States Naval Academy, Annapolis, MD 21402 USA.
³ Department of Chemistry, American University, Washington, DC 20016 USA. Electronic address: hchen@american.edu.
⁴ Department of Civil and Environmental Engineering, The George Washington University, Washington, DC 20052 USA. Electronic address: danmengshuai@gwu.edu.

PMID: 35739770
DOI: 10.1016/j.jhazmat.2022.129251

Abstract

Solar-driven photocatalytic generation of H₂O₂ over metal-free catalysts is a sustainable approach for value-added chemical production. Here, we synthesized chlorine-doped graphitic carbon nitride (Cl-doped g-C₃N₄) through a solvothermal method to effectively produce H₂O₂ with a rate of 1.19 ± 0.06 µM min^-1 under visible light irradiation, which was improved by 104 times compared to pristine g-C₃N₄. Continuous net production of H₂O₂ was realized at a rate of 2.78 ± 0.10 µM min^-1 up to 54 h with isopropanol as the hole scavenger, whereas H₂O₂ production was only sustained for ~ 6 h without scavengers. Both molecular simulations and advanced spectroscopic characterizations elucidated that the Cl dopant increased the charge transfer rate, decreased the bandgap, and reduced the activation energy of the rate-limiting step of O₂ reduction, all of which favored H₂O₂ production. This work implemented a novel metal-free photocatalyst for sustainable H₂O₂ production and elucidated the mechanism for promoting H₂O₂ production that can guide future photoreactive nanomaterial design.

Keywords: Doping; Graphitic carbon nitride; Metal-free photocatalysts; Sustainable production of H(2)O(2).