Recent progress of selective toluene oxidation via heterogeneous photocatalyst

Abstract

Benzaldehyde is an important fine chemical widely used in spices, dyes, medicine, pesticides, auxiliaries and synthetic materials. Heterogenous photocatalytic synthesis of benzaldehyde from toluene has been drawing increasing attention due to the relatively mild reaction conditions, high selectivity and easy recycling of the catalyst. Centered on the development of efficient photocatalysts, this article reviews the research progress of the photocatalytic selective oxidation of toluene in the past ten years. Different types of photocatalysts (including TiO2-based, Bi-based, CdS-based, g-C3N4-based, etc.) are discussed, along with the design philosophies and reaction mechanisms. Finally, being a longtime participant in this field, we provide our prospects on the design and preparation of the photocatalysts, the reaction mechanism, as well as the development of high efficiency photocatalytic reactors.