The Preparation Of Opal Photonic And The Research On Novel Nano-Photocatalytic Materials

Environmental problems related to organic pollutants bring severe threats to sustainable development of human.To address this significant,photocatalysis offers an idea of green and energy saying technology for completely eliminating all kinds of contaminants.A prerequisite for the development of photocatalytic technology is obtain photocatalysis.On account of the special structure of regular arrangement,Photonic crystal has the larger specific surface area.It is beneficial to the full contact of photocatalyst and pollution source in photocatalytic reaction,and then effectively enhance the photocatalytic efficiency.Under this theory we prepared polystyrene microspheres and PMMA microspheres.By comparing with PS studying,we conclude PMMA has the characters of short preparation circle,stable nature and easily storing at room temperature.PS has advantages,whose particle size is easy to control,and it has hight rate of success in the template production.TiO₂ is the most commonly used photocatalyst.However TiO₂ with large band gap can only exhibit hight photocatalytic activity under ultraviolet light,which significantly limits its practical applications.Taking the sunlight into account,it is indispensable to develop hight effective visible-light-driven photocatalysts.Recently,synthesis of photocatalysts effective in contaminant decomposition under visible light irradiation has become an area of growing interest.Bi₂WO₆ has advantage over TiO₂ in the visible light range.Bi₂WO₆is a typical oxide that posses excellent intrinsic physical and chemical properties due to its layered structure.It has been reported that Bi₂WO₆ nanostructures and microstructures show relatively hight photocatalytic activity for the degradation of rhodamine B under visible light irradiation.Carbon quantum dots?CQDs?have great attracted research interest in recent years.Thanks to the conjugated?structure of CQDs,they can act as electron transports and acceptors in photoexcited states,which makes them promising for applications in photocatalilysis fields.According to the formula Eg=hv?h is Planck's constant,v is the frequency of light?,the energy excitated by visible light is relatively low compared to ultraviolet light,so that it is unable to separate holes and electron pairs,so there was no more holes and oxidation potential can be obtained,the organic matter in water can not be completely degraded.In order to obtain more holes and oxidation potentials,upconversion luminescent materials have been widely used.We mixed rare earth ions in Bi₂WO₆,and the energy generated by the rare earth ions excited from infrared light transfers the energy to Bi₂WO₆.The holes and electron pairs between the valence band and the conduction band of Bi₂WO₆ are effectively separated,thereby enhancing the photocatalysis effect.Finally,in this article,carbon quantum dots and tombarthite ion impured Bi₂WO₆ were composited and tested for photocatalysis activity.The catalytic efficiency was increased by 30%.The mesoporous C₃N₄ of the large specific surface area was prepared by using the existing methods in the laboratory.In addition,the heterostructure was formed with Bi₂WO₆,which enhanced the catalytic efficiency of the original photocatalyst C₃N₄.And discuss the relationship between the amount of Bi₂WO₆ and the surface area of the composite.And determine the proportion of the photocatalyst to achieve the best catalytic effect.