Photocatalytic Dedegradation of Hydrofluorocarbon under Visible light Irradiation

Hydrofluorocarbons are difficult to remove from the water environment due to their inertness to photolysis, hydrolysis, and biodegradation. In the study, the rapid decomposition of hydrofluorocarbons was found in the presence of bismuth oxide as a photocatalyst under visible light irradiation. Compared with nano-TiO2 and direct photolysis, the photocatalysis by bismuth oxide can remove hydrofluorocarbons more efficiently under visible light irradiation (lambda > 420 nm). The effects of temperature, pH, and initial hydrofluorocarbons concentration on the photocatalytic decomposition rates were investigated. Based on the detection of reactive radicals, photocatalytic reduction by hydrated electron was determined as the major degradation route. The detailed defluorination pathway was also proposed.