Construction of immobilized films photocatalysts with CdS clusters decorated by metal Cd and BiOCl for photocatalytic degradation of tetracycline antibiotics

A kind of CdS/Cd-BiOCl immobilized films photocatalyst was prepared.The optical and physicochemical properties of the CdS/Cd-BiOCl photocatalysts were analysed,and the detailed characterization revealed CdS/Cd-BiOCl films photocatalyst with good charge carrier separation effect.The reusabilities and photocatalytic properties of the samples were studied.The 15%Cd S/Cd-Bi OCl photocatalyst exhibited superior performance in photocatalytic degradation of tetracycline(TC)and favorable stability under visible light irradiation.As for the photodegradation rate of TC,15%CdS/Cd-BiOCl exhibited an excellent photodegradation activity,which is 4.06 and 9.53 times higher than that of Cd S/Cd and Bi OCl,respectively.The results showed that dominant active species are·O_(2)^(-)and·OH radicals during photodegradation.The charge transfer in Z-scheme CdS/Cd-BiOCl films photocatalyst could synchronously generate conduct band(CB)electrons in BiOCl and valence band(VB)holes in CdS,and metal Cd served as electron mediator.This work can be a reference for the design of film photocatalysts and new insight for photodegradating towards contaminants.

Studies of Photocatalytic Kinetics on the Degradation of Bisphenol A （BPA） by Immobilized ZnO Nanoparticles in Aerated Photoreactors

The photocatalytic kinetics of BPA （4, 4＇-isopropylidenediphenol）, a representative endocrine disruptor, was explored using immobilized ZnO nanoparticles as a photocatalyst in a laboratory scale photocatalytic reactor. The conditions of photocatalytic degradation were optimized. Direct photocatalytic degradation of BPA was undertaken in an aqueous solution containing ZnO nanoparticles under the optimized experimental conditions. The effects of various factors, such as initial BPA concentrations, initial pH values and various anions （CI, NO3, COa2, SO42-, HCO3＂） were investigated. In the case of the nanoparticles derived films, the photocatalytic efficiency was found not to be remarkably related with the calcination temperature employed in the coating process. Screen-printed ZnO nanoparticles films obtained in the optimal processing conditions showed that the photocatalytic activity is comparable to ZnO nanoparticles in aqueous suspensions. Over 90% degradation efficiency of BPA was achieved under the optimum conditions. The degradation rates in all photocatalytic experiments were linear with the degradation efficiencies of BPA by regression analysis （r ≥ 0.99）. The results showed that the degradation kinetics of BPA in the reactor with immobilized nano-ZnO film as photocatalyst was in agreement with a pseudo-first order rate law.

Properties of fluorescence based on the immobilization of graphene oxide quantum dots in nanostructured porous silicon films

The fluorescence of graphene oxide quantum dots （GOQDs） that are infiltrated into porous silicon （PSi） is investigated. By dropping activated GOQDs solution onto silanized PSi samples, GOQDs are successfully in- filtrated into a PSi device. The results indicate that the intensity of the fluorescence of the GOQD-inflltrated multilayer with a high reflection band located at its fluorescence spectra scope is approximately double that of the single layer sample. This indicates that the multilayer GOQD-infiltrated PSi substrate is a suitable material for the preparation of sensitive photoluminescence biosensors.