Preparation Of Functional Fabric Loaded With Ag₃PO₄/TiO₂ And Its Degradation Of Organic Pollutants

As a kind of green technology,photocatalytic has been widely used as one kind of solar energy to deal with organic pollutants in the environment.Among the numerous semiconductor photocatalysts,Silver phosphate?Ag₃PO₄?,a kind of materials with quantum efficiency up to 90%,which can absorb sunlight with wavelength short than 520 nm,has been widely researched for its extremely high photooxidative capabilities under solar radiation.However,the large-scale application of Ag₃PO₄ is still limited by its low stability and high cost.It is found that the combination of two kinds of semiconductor materials with different band width can promote the separation of light carrier and improve the photocatalytic activity.However,they are easy to agglomerate and not easy to recycling during the application of these catalysts under powder state.Based on this,Ag₃PO₄ and titanium dioxide?TiO₂?were used to prepare silver phosphate/titanium dioxide?Ag₃PO₄/TiO₂?composite photocatalyst and loaded onto the surface of cotton fabric in this article,in order to achieve perfect photocatalytic degradation and easy recycle property.The article was divided into three parts:In the first part,the silver phosphate photocatalyst was prepared by silver ammonia assisted method and its application was researched.After the optimization of its preparation condition such as the concentration of silver nitrate,the concentration of sodium hydrogen phosphate,reaction time and the dosage of ethanol in the washing process,the silver phosphate catalyst was prepared with 0.1 mol/L silver nitrate,0.1 mol/L sodium hydrogen phosphate and 0.1 mol/L of ammonia and the mixture was reacted for 30 min.The morphology,crystal structure and optical properties of the photocatalyst of silver phosphate were characterized by scanning electron microscopy?SEM?,X-ray diffraction?XRD?and UV-Vis diffuse reflectance spectra?DRS?.The results showed that:the silver phosphate was approximate to dodecahedra structure with sharp edges and smooth surface,and it presented certain agglomeration phenomenon.The diffraction peaks of silver phosphate were in accordance with the standard card of the silver phosphate.It has a standard body centered cubic structure with high crystalline,low crystal defects and without any impurity.The silver phosphate can absorb light shorter than 506 nm,which is in the range of solar radiation,and it has been demonstrated that it has excellent photocatalytic degradation to rhodamine B and a certain amount of degradation ability to formaldehyde.In the second part,the silver phosphate/titanium dioxide composite photocatalyst was prepared and its application on the degradation of rhodamine B and formaldehyde was studied.The silver phosphate nanoparticles were deposited on the surface of commercial titanium dioxide P25 by the method of in-situ deposition,and the Ag₃PO₄/TiO₂ composite photocatalyst was prepared at room temperature.Fourier Transform Infrared Spectrometer?FT-IR??XRD?X-ray photoelectron spectroscopy?XPS??SEM?Transmission Electron Microscope?TEM?and DRS were used to characterize the crystal structure,surface chemical states,morphology and optical properties of the Ag₃PO₄/TiO₂ composite photocatalyst.The effect of molar ratio of Ag₃PO₄ and TiO₂ on the photocatalytic degradation to rhodamine B and formaldehyde was discussed,while the mechanism of photocatalytic reaction of Ag₃PO₄/TiO₂composite photocatalyst was studied by reactive species trapping experiments,too.The results showed that:in the structure of Ag₃PO₄/TiO₂ composite photocatalyst,Ag₃PO₄ nanoparticles loaded on the surface of TiO₂ to form a heterostructure.The composite photocatalyst had strong absorption in the range of solar radiation;When the mole ratio of Ag₃PO₄ and TiO₂ was 5:5,the composite photocatalyst presented better photocatalytic degradation performance compared with Ag₃PO₄ catalyst;While h⁺and·O₂^-are the main reactive oxygen species during the photocatalytic degradation process.In the third part,the Ag₃PO₄/TiO₂ composite photocatalyst was loaded on the surface of cotton fabric to prepare photocatalytic functional cotton fabric by padding and coating method.The crystal structure of loaded Ag₃PO₄/TiO₂,surface morphology and optical properties of the cotton fabric were characterized by XRD?SEM and DRS.Photocatalytic performance of the photocatalytic functional fabric was tested in the application of photocatalytic degradation to rhodamine B and formaldehyde.At the same time,the recycling properties of the photocatalytic functional fabric and the photocatalytic degradation performance of the loaded fabric by padding method for the commercial dyes were also discussed.The results showed that:loading the Ag₃PO₄/TiO₂ composite photocatalyst on the surface of cotton fabric by padding method provided it better photocatalytic degradation performance to rhodamine B and formaldehyde,as well as the perfect recycling performance and photocatalytic degradation capability to commercial dyes.In conclusion,the photocatalytic degradation ability of silver phosphate photocatalyst can be improved by the preparation of Ag₃PO₄/TiO₂ composite photocatalyst via in-situ deposition method,by which silver phosphate nanoparticles were deposited on the surface of commercial titanium dioxide P25 at room temperature.When loaded on the surface of the cotton fabric by padding method,the Ag₃PO₄/TiO₂ composite photocatalyst provided the fabric with perfect photocatalytic degradation performance,recycling performance and photocatalytic capability to degrade commercial dyes.