Research On Optical Properties Of TiO₂/GO Nano-materials And Their Catalytic Degradation Of VOCs

Organic volatile gases?VOCs?are distributed in the atmosphere with low concentration and wide variety of kinds,which is one of the main sources of environmental pollution.Photocatalytic degradation of titanium dioxide?TiO₂?is one of the main methods to control environmental pollution.However,TiO₂ is a semiconductor material with wide band gap,which leads to limitations in the absorption of light energy.Therefore,it has become the main research content of many scholars to expand the scope of light absorption and improving photocatalytic efficiency by improving the surface and structure of TiO₂photocatalyst.In this paper,starting from titanium dioxide/graphene oxide?TiO₂/GO?nanomaterials,the effects of different process parameters on the optical properties and photocatalytic degradation of toluene of the composites were studied through doping modification of the composites,and the catalytic mechanism was summarized and analyzed.The main research results of this paper are as follows:In order to improve the optical properties of TiO₂ nanocomposites,N and Fe ions were doped into the composites,and the relationship between the morphology and structure changes after N and Fe ions doping and the optical properties of the nanocomposites were studied.The results show that after N ions doping,the overlap of N 2p and O 2p orbits occurs,which reduces the forbidden gap of TiO₂,resulting in the red shift of the absorption edge of the composites.Fe doping forms an electron trap,which reduces the electron-hole combination efficiency and improves the photocatalytic efficiency to as high as 90.5%.The effects of hydrothermal time and GO content on the optical absorption properties and photocatalytic efficiency of the composite were studied.The results show that the bonding between TiO₂ and GO can take place in a certain range of hydrothermal time,and the agglomeration of the composites can be improved with the increase of hydrothermal time.At the same time,N and Fe ions can be better doped into composite materials,leading to red shift of absorption edge.GO content is also the main factor affecting the optical properties and photocatalytic efficiency of TiO₂/GO composites.As an electron transfer acceptor,GO effectively improves the separation efficiency of electron-hole pairs,and then improves the photocatalytic degradation efficiency to 92.9%.Finally,the effect of doping Pd ions on the optical and catalytic properties of the composites is studied.Pd ions can enter into the lattice of TiO₂,introduce impurity levels,and form electron traps.On this basis,the effect of the content of TiO₂ on the properties of the materials was further studied.Appropriate amount of TiO₂ can improve the photocatalytic activity.The main reason is that the existence of TiO₂ can provide more active sites.At the same time,more chemical bonds between TiO₂ and reduced graphene oxide can be formed,which can better separate electron-hole pairs and then extract them.And then the efficiency of photocatalytic degradation of toluene was improved.In conclusion,the optical and catalytic properties of nanomaterials have been studied and it is found that uniform morphology distribution,perfect crystal structure,high electron-hole separation efficiency and high specific surface area are important factors to improve the properties of nanomaterials.By introducing different impurity ions into the preparation process and changing the process parameters,the above factors can be affected,thus regulating the optical and photocatalytic properties of nanomaterials.