Selective oxidation of toluene to benzaldehyde over Pd/BiVO4 particles under blue to green light irradiation

Selective synthesis of organic chemicals such as oxidation of toluene to benzaldehyde using sunlight is necessary for its sustainable and environment-friendly applications. The photocatalytic reaction using semiconductor photocatalysts is a promising approach for sunlight-induced organic synthesis due to its significant advantages of operation under mild conditions, stability, and recyclicity. TiO2 is one of the most widely studied photocatalysts; however, the low selectivity for partial oxidation due to the complete decomposition to CO2 and lack of utilization of visible-light hampers its practical application. Here, we successfully demonstrated selective oxidation of toluene to benzaldehyde using a Pd-loaded BiVO4 photocatalyst under visible light irradiation. Furthermore, we confirmed that the reaction proceeds even under light irradiation up to 520 nm; this is the first report using blue-to-green light-responsive semiconductor photocatalyst for converting toluene to benzaldehyde. Achieving efficient organic synthesis under visible light using semiconductor photocatalyst is an important step toward solar-to-chemical conversion.