Novel BiOCl/BiCl3Br–CTA Heterostructure Photocatalyst with Abundant Oxygen Vacancies and a Superoleophilic Surface for Promoting Selective Oxidation of Toluene

Toluene Oxidation: CO2 vs Benzaldehyde: Current Status and Future Perspectives

Toluene is a common and significant volatile organic compound (VOC). Although it finds extensive application in various industrial processes (chemical manufacturing, paint and adhesive production, and as a solvent), it creates a huge environmental impact when emitted freely into the atmosphere. Two solutions were found to mitigate the emission of this pollutant: the total oxidation to CO2 and H2O and the selective oxidation into benzaldehyde. This review discusses the two main alternatives for tackling this problem: converting the toluene into carbon dioxide by total oxidation or into benzaldehyde by selective oxidation. It presents new catalytic advances, new trends, and the advantages and disadvantages of both methods.

Panax notoginseng powder -assisted preparation of carbon-quantum-dots/BiOCl with enriched oxygen vacancies and boosted photocatalytic performance

Low activity of photocatalysts is a serious bottleneck to the practical application of photocatalytic technology. In this paper, a series of BiOCl composite photocatalysts containing carbon quantum dots (CQDs) were successfully prepared by adding Panax notoginseng powder (PNP) to the solvothermal synthesis system of BiOCl as a template agent and a raw material for 0D CQDs. CQDs/BiOCl exhibit 2D flake structures and 3D flower-like microspheres self-assembled from thin flakes, holding rich oxygen vacancies (OVs). After detailed characterization, it was found that the amount of OVs on BiOCl could be regulated according to the amount of PNP added. The CQDs/OVs-BiOCl photocatalysts exhibit higher photogenerated charge separation efficiency and photocatalytic activity than the bare BiOCl. When the mass ratio of PNP/BiOCl is 1.0%, the photocatalyst demonstrates the maximum degradation activity for rhodamine B (RhB) and perfluorooctanoic acid (PFOA). In view of the solid observations, a photocatalytic enhancement mechanism of CQDs/BiOCl was elucidated.

Nitrogen-doped 3D hollow carbon spheres for efficient selective oxidation of C–H bonds under mild conditions

Nitrogen-doped hollow mesoporous carbon spheres present excellent conversion and selectivity in the selective oxidation of ethylbenzene at 50 °C.

Efficient photocatalytic toluene degradation over heterojunction of GQDs@BiOCl ultrathin nanosheets with selective benzoic acid activation

Photocatalytic toluene degradation has attracted tremendous attention because of the growing environmental problem. However, conventional photocatalytic materials used for toluene degradation usually suffer from low carrier separation efficiency and poor stability which will degrade the catalytic performance. Herein, we report the synthesis of a novel heterostructure of GQDs@BiOCl ultrathin nanosheets where the GQDs can rapidly capture and transport photogenerated electrons for effective charge separation, promoting the generation of more reactive oxygen species (·O₂^- and ·OH radicals) for toluene degradation. In situ DRIFTS measurement and theoretical calculation are performed to unveil the reaction intermediates and the underlying toluene oxidation mechanism. The GQDs@BiOCl heterojunction could facilitate the adsorption and conversion of toluene and the reaction intermediates. Especially, the heterojunction greatly enhances the activation and conversion of benzoic acid and thus expedites the complete toluene degradation. This work presents a new insight on the design of high-performance photocatalysts for efficient degradation of typical air pollutants.