Photothermal-assisted photocatalytic degradation with ultrahigh solar utilization: Towards practical application

Abstract The utilization of long-wave light (1000–2500 nm) in the solar spectrum is a difficulty in photocatalysis. Based on the Arrhenius equation, the activated carbon (AC)/graphitic carbon nitride (CN) composites were designed for photothermal-assisted photocatalytic water treatment. The short-wave solar energy can be converted to chemical energy on CN, and the long-wave solar energy to thermal energy by AC. The energetics and the interfacial charge transfer of activated carbon (AC)/graphitic carbon nitride (CN) composites (ACCN) were improved owing to the π bond between AC and CN. The excellent light absorption capacity (over 80%) led to higher photocatalytic reaction temperature due to the photothermal effect. The higher temperature accelerated the photocatalytic reaction and facilitates the charge transfer on ACCN. Hence, the optimal ACCN sample with good balance between photothermal and photocatalytic property could degrade 98% of sulfamerazine under simulated solar irradiation in 60 min. This work not only developed efficient and low-cost (~$1/kg) carbon-based photocatalysts with ultrahigh solar utilization, but also discussed the mechanism of photothermal effect on photocatalytic reaction.