Effect of cations on the structure, physico-chemical properties and photocatalytic behaviors of silver-doped zeolite Y

摘要

Two different types of silver-doped zeolite Y (Ag-Nay, Ag-HY) were synthesized by one-step and two-step ion exchange methods, which were verified excellent photodegradation performance of RhB. The composition, structure, morphology, and optical absorption properties of the as-prepared samples were characterized by XRF, XRD, SEM, BET, PL and UV-Vis adsorption spectrum, respectively. The results showed that NaY had better cation exchange ability than HY in Ag+ exchange experiment. But Ag-HY had more mesopores and the external specific surface area, almost more than twice that of Ag-Nay. Moreover, both of Ag+ -doped zeolites exhibited better absorbance and lower electron-hole recombination than HY according to UV-vis and PL detection. The photo-catalytic activity of Ag+-doped zeolites was evaluated by photodegrading RhB. It was found interestingly that using Ag-HY as photocatalyst, about 70% RhB was degraded in the first 10 min, and almost all RhB was completely removed in 50 min under visible light irradiation. A possible enhanced photocatalytic mechanism of Ag+-doped zeolite was proposed as the excellent surface adsorption of zeolite, enhanced absorbance and the effective separation of photogenerated electron-hole pairs.