Research On The Preparation And Performance Of Silver Phosphate Composite Photocatalysts

Silver phosphate,as a novel visible-light-driven photocatalysts,which has attracted much attention for its strong photo-oxidation capabilities and high quantum yield under the visible light.However,the practical application of Ag₃PO₄ has been seriously limits due to its slight solubility in solution,photo-correded and fast recombination of photo-generated charge carriers.In the present works,the photocatalytic activity of Ag₃PO₄ can be improved by respectively combining with AgBr,Ag₂S and graphene oxide（GO）to form different Ag₃PO₄ semiconductor heterojunctions.In this paper,AgBr/Ag₃PO₄（ABAP）composite photocatalyst were synthesized by a facile one-pot anion exchange methods and characterized by X-ray diffraction（XRD）,scanning electron microscopy（SEM）,X-ray photoelectron spectroscopy（XPS）and UV-Visible reflection spectroscopy（UV-VisDRS）techniques.Under the irradiation of visible light,photocatalytic degradation efficiency of RhB was about 96.9%for ABAP-48%showed that the photocatalytic degradation efficiency of ABAP-48% composite,which higher than other ABAP-X% composite photocatalysts and pure AgBr and pure Ag₃PO₄ in the experimental system.In addition,the ABAP exhibited excellent stability and recyclability after five cycles.The active specie·O₂^-was found to play a key role during the photocatalytic reaction.In addition,a series of different S/P molar ratios of Ag₃PO₄/Ag₂S（APAS）composite photocatalysts were synthesized through a facile one-pot anion exchange methods.The as-synthesized samples were characterized by X-ray diffraction XRD),scanning electron microscopy（SEM）,X-ray photoelectron spectroscopy（XPS）and UV-Visible reflection spectroscopy（UV-Vis DRS）,and its show that Ag₂S nanoparticles are successfully dispersed on the surface of Ag₃PO₄.Under visible light irradation,the experiment of photocatalytic degradation of RhB showed that the high photocatalytic performance for the degradation of RhB over APAS-1%which were 2.5 times and 9.2 times of that pure Ag₃PO₄ and pure Ag₂S,respectively.The APAS-1%showed stable photocatalytic activities after four successive cycles.h⁺was the main active species in reaction process.In the present work,ternary Ag₃PO₄/Ag₂S/GO composite photocatalyst（APAS-GO）were prepared by combining GO with Ag₃PO₄ and Ag₂S.The physico-chemical properties of the material were characterized by X-ray diffraction XRD),scanning electron microscopy（SEM）,X-ray photoelectron spectroscopy（XPS）and UV-Visible reflection spectroscopy（UV-Vis DRS）and Fourier Transform Infrared（FT-IR）,and the morphology analysis indicated that Ag₃PO₄ particles were soft GO enveloped Ag₃PO₄ and Ag₂S.Under the irradiation of visible light,the experiment of photocatalytic degradation of RhB showed that the high photocatalytic performance for the degradation of RhB over APAS-GO-4%,the photodegradation rate of APAS-GO-4% was almost 2.6,8,10.6,11.9 folds as high as those of APAS,pure Ag₃PO₄,pure Ag₂S and GO,respectively.The photocatalytic activities of the APAS-GO-4% composites can be kept even after four successive cycles of photofegradation,indicating the APAS-GO inhibited high stability.h⁺and·O₂^- were the crucial active species in the RhB degradation.