Fabrication of monodispersed plasmonic photocatalysts on activated carbon with the carbon source and reduction property of sewage sludge

Abstract

Fabrication of porous carbon supported plasmonic photocatalysts with the low-cost carbon waste is a promising strategy for resource utilization. Herein, a sewage sludge was chosen for the synthesis of the sewage sludge activated carbon (SSC) supported Bi3+-doped TiO2 and Bi0 (SSCTB) photocatalysts. Through the pyrolytic carbonization, the sewage sludge was simultaneously displayed as the carbon precursor and reduction agent for the formation of SSC and Bi0, respectively. The results showed that the monodispersed Bi3+-doped TiO2 nanoparticles embedded with Bi0 were in-situ formed on the porous SSC. The synergistic effect of the localized surface plasmon resonance (LSPR) of Bi0, Bi3+ doping in TiO2, and the carbon of SSC greatly improved the light response ability and charge separation efficiency of the SSCTB samples. Under UV–Vis-NIR light irradiation for 60 min, the SSCTB sample with 5% of Bi (SSCTB5) possessed higher degradation rate of 47% for methyl orange compared with those of other samples. The photocatalytic mechanism was proposed based on the LSPR effect and the charge transfer process, where SSCTB5 was able to yield the highest numbers of OH and O2− radicals. The fabrication of the SSC supported plasmonic photocatalysts provides a cost-efficient strategy for the resource utilization of sewage sludge.