The key role of surface hydroxyls on the activity and selectivity in photocatalytic degradation of organic pollutants and NO removal

Abstract

Herein, we fabricated hydroxyl groups decorated Bi4O5I2 nanosheets, and the contents of hydroxyl groups on the surface could be controlled by changing the reducibility of organic solvents. The stronger reducibility of organic solvents, the more hydroxyl groups on the surface. The hydroxyl groups on the surface of Bi4O5I2 nanosheets have significant effects on photocatalytic activity. For degradation of organic pollutants, the surface hydroxyls form hydrogen bonds with organic pollutants, which is conducive to the adsorption of the substrates. For NO removal, the NO adsorbed on the hydroxyl groups is more oxidized into a toxic by-product NO2 instead of NO3-, so less hydroxyl groups are important for photocatalysts towards NO removal. These new discoveries provide new insights to improve photocatalytic activities by modulating surface functional groups of photocatalysts.