Heterostructural Ag3PO4/UiO-66 composite for highly efficient visible-light photocatalysts with long-term stability

To aim to extent the advantage of the high optical absorbance and overcome the shortcoming of the instability on Ag3PO4, a novel visible-light-driven heterostructure photocatalyst Ag3PO4/UiO-66 (APU) composite with a synergistic effect of adsorption enrichment and photocatalysis degradation has been successfully fabricated via a facile chemical bath deposition method. The APU photocatalyst is not only favorable to increasing the absorption ability for organic pollutants owing to a larger surface area, but also promotes the separation and transformation of electron-hole pairs due to the good conductivity performance in the presence of Ag/Ag3PO4/UiO-66 structure. Under visible-light illumination, the APU-15% composite photocatalyst has exhibited the excellent removal capacity, and the degradation efficiency can be up to 100% in 18 min. The degradation constant are about 80 and 2.7 times higher than those of bare UiO-66 and Ag3PO4 for the removal of RhB in the dynamic system, respectively. The enhancement of removal efficiency is due to a synergistic effect of adsorption enrichment and photocatalysis degradation. The removal rate of the APU-15% composite photocatalyst has only 9.5% decrease for 5 cycles of the photoreaction, showing the relatively good stability. The trapping experiment and ESR show the main active species is O2(center dot)(-). Furthermore, the photocatalytic mechanism has been proposed in the end.