Enhanced photocatalytic degradation for thiophene by Ag/α-MoO₃ heterojunction under visible-light irradiation

Ag/α-MoO₃ heterojunctions were prepared by a photoreduction process and characterized using XRD, TEM, UV–Vis-DRS, EDS, XPS, PL, EIS and PT. Ag/α-MoO₃ heterojunctions exhibited excellent photocatalytic oxidative desulfurization activity for thiophene under visible-light irradiation. The removal efficiency of 5% Ag/α-MoO₃ composites could get to 98.3% with 1.5 g L⁻¹ amount of catalyst used under visible-light irradiation for 270 min, which is 2.5 times as high as that of pure α-MoO₃ nanobelts. The stability of as-prepared Ag/α-MoO₃ heterojunctions were investigated through recycling run experiment, which the desulfurization rate of 5 wt% Ag/α-MoO₃ for thiophen still remained 92.8% after five consecutive cycles. Furthermore, the active species trapping experiment confirmed that h⁺ and ^·O₂ ⁻ were the main active in photocatalytic degradation process for thiophene. Additionally, the mechanism of the enhanced photocatalytic activity for Ag/α-MoO₃ was proposed. These features demonstrate that the Ag/α-MoO₃ heterojunctions have great application potential for refractory pollutants’ removal from fuel oil.