Influence of yolk-shell Au@TiO2 structure induced photocatalytic activity towards gaseous pollutant degradation under visible light

Core-shell and yolk-shell Au@TiO2 NPs were successfully synthesized, and the morphology differences were observed. Its photocatalytic activity was evaluated by photocatalytic oxidation of gaseous toluene under visible light illumination. The results indicated that yolk-shell Au@TiO2 exhibited superior photocatalytic properties and demonstrated a good stability. Almost 57.3% of gaseous toluene was removed over 0.14 at% yolk-shell Au@TiO2 in 3 h. It could also be reused for several times without corrosion. Furthermore, the comprehensive effect of LSPR response of Au, high cavity volume of yolk-shell structure, larger specific surface area, more mesoporous and the existence of Ti3+ were all benefit for the photocatalytic process. ESR tests also confirmed that h(+), (OH)-O-center dot, O-center dot(2)- and Ti3+ generated from yolk-shell Au@TiO2 were the main active species in the photo catalytic degradation progress of gaseous toluene under visible light irradiation.