Preparation And Properties Of WO₃ Composite Photocatalysts Through Templatr Assisted Methods

Semiconductor photocatalytic reaction technology,due to its advantages of mild reaction conditions,high efficiency,low energy consumption,and no secondary pollution,has highlighted its advantages in solving the environmental pollution by human beings.Due to the advantages of visible light activity,simple preparation method and stability,WO₃ semiconductor photocatalyst has been widely used in the field of photocatalytic degradation of organic pollutant.The core of photocatalytic technology is the research and development of photocatalytic materials.However,low quantum efficiency,fewer surface active sites and higher electron-hole recombination rate affect the photocatalytic activity of WO₃.Based on the above problems,this paper prepared a series of WO₃-based composite semiconductor photocatalysts by the template assisted method,characterized the composition morphology,photoelectric property and degradation property of the samples.The influence of the type of template and the component mass ratio in the composite semiconductor were systematically studied.In addition,the mechanism of photocatalyst degradation was also studied.The main contents are as follows:?1?Soapless emulsion polymerization was used to prepare PMMA templates.Ag₃PO₄/WO₃ composite photocatalyst was prepared by depositing Ag₃PO₄ particles on the WO₃ prepared by PMMA template.The influence of template and Ag₃PO₄:WO₃ mass ratio on the photocatalytic performance of the composite catalyst was studied.PMMA template can increase the specific surface area of the catalyst to increase the photocatalytic activity site.When the molar mass ratio of Ag₃PO₄:WO₃ is 2:8,Ag₃PO₄/WO₃ composite catalyst shows the best visible light degradation performance,and can degrade 100%methylene blue?MB?and 81%methyl 4-hydroxybenzoate within 5 minutes and 90 minutes respectively.Moreover,Ag₃PO₄/WO₃ composite catalyst has good stability.?2?Low-cost polyurethane?PU?sponge was selected as the template to prepare Ag₃PO₄/WO₃ composite photocatalyst.Non-metallic element doping would be introduced due to the use of PU template.Therefore,C,N co-doped Ag₃PO₄/WO₃ composite photocatalyst was prepared.The doping of C and N elements was proved by X-ray photoelectron spectroscopy?XPS?and X-ray diffraction?XRD?.Experiments show that,compared with pure WO₃,Ag₃PO₄and Ag₃PO₄/WO₃ photocatalysts prepared without template,PU template assisted preparation of C,N co-doped Ag₃PO₄/WO₃ composite photocatalyst shows the best catalytic activity and stability.MB was completely degraded in 4minutes under visible light,and 80%methyl 4-hydroxybenzoate was degraded in 90 minutes.The high degradation efficiency is mainly attributed to the synergistic effect of Ag₃PO₄ and WO₃,which promotes the separation efficiency and migration rate,the large specific surface area advantage,and the C,N element doping brought by the template.?3?In order to reduce the cost,PU sponge template was used to synthesize C,N co-doped WO₃/TiO₂/RGO photocatalysts.Firstly,the C,N co-doped TiO₂/WO₃ composite photocatalyst was prepared using PU sponge template.The C,N co-doped TiO₂/WO₃ composite photocatalyst was compounded with RGO to produce the C and N co-doped TiO₂/WO₃/RGO composite photocatalyst.By visible light degradation of methylene blue,the influence of component mass ratio,PU template and RGO on the catalytic activity of the composite catalyst was studied.TiO₂/WO₃/RGO composite photocatalyst?TiO₂:WO₃ molar mass ratio:19:1?has the best degradation performance compared with the catalyst prepared by a single component and C,N co-doped TiO₂/WO₃ composite catalyst.88%MB was degraded in 90 minutes under visible light irradiation.