Nanoarchitectonics in the Ionothermal Synthesis for Nucleation of Crystalline Potassium Poly (heptazine imide) Towards an Enhanced Solar‐Driven H2O2 Production. Issue 59 (23rd August 2022)

• Record Type: Journal Article
• Authors: Yang, Zhenchun; Li, Lina; Cui, Jiahao; Shao, Siting; Zeng, Shiqi; Wang, Kun; Ma, Dongge; Hu, Chun; Zhao, Yubao
• Is Part Of: Chemistry. Volume 28:Issue 59(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-08-23
• Subjects: carbon nitride -- eutectic salt -- hydrogen peroxide -- oxygen reduction -- photocatalysis; Chemistry -- Periodicals; 540
• DOI: 10.1002/chem.202202122
• Languages: English
• ISSNs: 0947-6539

Abstract

Abstract: Solar‐driven selective oxygen reduction reaction on polymeric carbon nitride framework is one of the most promising approaches toward sustainable H2 O2 production. Potassium poly(heptazine imide) (PHI), with regular metal sites in the framework and favorable crystalline structure, is highly active for photocatalytic selective 2e oxygen reduction to produce H2 O2 . By introducing NH4 Cl into the eutectic KCl‐LiCl salt mixture, the PHI framework exhibits a remarkable performance for photocatalytic production of H2 O2, for example, a record high H2 O2 photo‐production rate of 29.5 μmol h −1 mg −1 . The efficient photocatalytic performance is attributed to the favorable properties of the new PHI framework, such as improved porosity, negatively shifted LUMO position, enhanced exciton dissociation and charges migration properties. A mechanistic investigation by quenching and electron spin resonance technique reveals the critical role of superoxide radicals for the formation singlet oxygen, and the singlet oxygen is one of the critical intermediates towards the formation of the H2 O2 by proton extraction from the ethanol. Abstract : Addition of NH4 Cl in the eutectic salt mixture of KCl/LiCl can regulate the polymerization process and generate a potassium poly(heptazine imide) framework with favorable features, such as increased surface area, strengthened reduction power, improved exciton dissociation and charge migration properties, which contribute to a significantly boosted catalytic performance in photo‐production of hydrogen peroxide from selective oxygen reduction.