Daylight-driven catalytic removal of pyridine over Ag-embedded ZnO porous nanosheets

Abstract

Structure of heterogeneous photocatalyst with adequate coupling interface has an important effect on energy transfer and photoinduced electron-hole pairs separation. In this work, Ag-embedded ZnO heterogeneous porous nanosheets (PNSs) have been synthesized by thermal pyrolyzing of Ag2CO3-modified Zn5(CO3)2(OH)6 nanosheets at 400 °C. Photoelectron spectra and X-ray diffraction measurements demonstrate that there exists an adequate coupling between Ag and ZnO phase. Ag-embedded ZnO PNSs, in contrast to bare ZnO PNSs, performs 6-fold enhancement in natural-daylight-driven degradation of pyridine which requires participation of ·OH radicals. This result demonstrates that the adequate coupling interface between Ag and ZnO for Ag-embedded ZnO PNSs promotes an energy transfer from local surface plasma resonance of Ag nanoparticles to bound excitons in ZnO region, activating them to dissociate into free photoinduced carriers. In addition, external control experiments indicate that the best photocatalytic degradation is obtained in the 7–10 pH range of 10 mg/L pyridine solution in presence of 0.5 g/L photocatalyst dosage. The optimal Ag-embedded ZnO PNSs under outdoor daylight irradiation also performs an efficiently photocatalytic degradability for pyridine present in ground water. Our work provides a new approach to fabricate ZnO-based photocatalyst with efficient energy transfer for treating stubborn organics present in polluted water.