A Strategy for One-Pot Conversion of Organic Pollutants into Useful Hydrocarbons through Coupling Photodegradation of MB with Photoreduction of CO2

A strategy was developed to couple photocatalytic oxidation with photocatalytic reduction technology to realize one-pot conversion of MB into hydrocarbons for the first time. In this approach, organic pollutants were first decomposed into CO2 by photodegradation and then the as-obtained CO2 was converted into CH3OH, C2H5OH, and CH4 through photocatalytic reduction of CO2 under solar spectrum irradiation by using GQDs/V-TiO2 catalysts. The experimental results show that 5%GQDs/V-TiO2 has the best photocatalytic activity and the product rates of CH3OH, C2H5OH, and CH4 are 13.24, 5.65, and 0.445 μmol g–1 h–1, respectively. The corresponding apparent quantum efficiency is 4.87% at 420 nm. The one-pot conversion of MB into hydrocarbons was demonstrated by a series of experiments. The photocatalytic mechanisms of one-pot conversion of MB into hydrocarbons were proposed to explain the detailed photocatalytic process.