Synthesis Of New Silver Matrix Composites And Study On Photocatalytic Properties

Silver-based semiconductor catalysts have special hybrid orbitals Ag 4d and O 2p,which have excellent advantages in photo-carrier current migration,and have a wide visible light response range and good photocatalytic activity.In this paper,AgCl and AgVO3 were studied as semiconductor objects,and they were combined with WO3,?-FeOOH and BiFeWO6.The sample materials were tested by XRD,FTIR,UV,SEM,TEM,XPS and other characterization methods to determine the composition of the sample material,light absorption edge,surface morphology,bond energy and other information.The photocatalytic activity of the sample material was evaluated by degrading Rhodamine B and MB under visible light irradiation.Due to the proper band position between the two single semiconductor photocatalytic materials,a type II heterojunction is constructed,which enables the photoexcited charge carriers to be quickly separated and moved,while narrowing the forbidden band width to improve the visible light response range of the composite.It helps to generate more photogenerated electron hole pairs,thereby improving photocatalytic performance.1.The ?-Ag2WO4 and hydrochloric acid were used as precursors to synthesize WO3/AgCl composite photocatalyst by hydrothermal reaction.The WA-1 complex achieved maximum photocatalytic activity,showing complete removal of RhB(100%)within 30 minutes of illumination.The photocatalytic activity of the WO3/AgCl composite remained almost constant even after the fourth cycle.·O2·free radicals play a key role in photodegradation reactions due to their strong oxidizing power.The photocatalytic degradation mechanism of WO3/AgCl composites on organic pollutants RhB was also proposed.2.Uniform ?-FeOOH nanorods were synthesized by solvothermal method,and then a series of ?-FeOOH/?-AgVO3 nanocomposites were synthesized by simple coprecipitation method.?-FeOOH nanorods are attached to the surface of nanorod-like ?-AgVO3.Good interfacial contact between ?-FeOOH and ?-AgVO3 can reduce hole-electron recombination and promote charge transfer between them to improve photocatalytic activity of nanocomposites..The ?-FeOOH/?-AgVO3 nanocomposite achieved a maximum degradation efficiency of 88.0%in 90 minutes.The absorption edge of the ?-FeOOH/?-AgVO3 nanocomposite is between the pure ?-FeOOH and pure ?-AgVO3.Studies have shown that h+and ·O2-are important active substances in the degradation process of RhB.3.A novel BiFeWO6/a-AgVO3 composite photocatalyst was proposed and prepared.Compared with pure ?-AgVO3 and BiFeWO6,the maximum rate constant of BiFeWO6/?-AgVO3 complex with 4mg BiFeWO6 was 0.0247 min-1,which was 4.5 and 35 times higher than that of pure BiFeWO6 and ?-AgVO3,respectively.And it shows good cycle stability,h+and ·O2-are important active substances in the degradation process of RhB.