Hydrothermal Synthesis Of TiO₂/Graphene Composite And Its Photocatalytic Activity

Photocatalysis technology,a new technology emerging in the 20th century,was widely used in air purification,water treatment,disinfection and other fields.TiO₂ has become the first choice of photocatalytic technology because of its non-toxic,cheap and high activity.Graphene,a kind of advanced new material,has become a popular substrate for photocatalytic technology due to its high adsorption and high conductivity.The purpose of this paper is to make the best use of TiO₂ and graphene and achieve the highest photocatalytic performance.Hummers'method was used to obtain graphene oxide?GO?.P25 and titanium sulfate was selected as the titanium source,Mechanical stirring hydrothermal method and in-situ hydrothermal synthesis method was used in the preparation of P-G and T-G series of TiO₂/GO composite materials.The influences of feed ratio,hydrothermal time,hydrothermal temperature,calcination time and calcination temperature on the photocatalytic activity of the composites were investigated.T-G samples with titanium sulfate as titanium source,graphene mass fraction of 5%,hydrothermal temperature of 120^oC,hydrothermal time of 12h,calcination temperature of 400^oC and calcination time of 0.5h show the best photocatalytic performance.For the T-G reaction system,a certain amount of induction agents containing both hydrophilic groups and hydrophobic groups are added,including sodium dodecyl sulfate?SDS?,polyvinylpyrrolidone?PVP?,and glucose?Glucose?.The difference of the morphology,structure and photocatalytic activity of the composites were investigated for different induction additives.It was found that a anatase mesoporous material was synthesized glucose being the induction agent and their photocatalytic rate were 4 times that of commercial P25.The degradation rate of methyl orange can reach 92%after 30 min light irradiation.Influence of other possible components in actual sewage,such as alcohols,hydrogen peroxide,potassium persulfate and anion on the performance of the composite materials were investigated.It was found that hydrogen peroxide and potassium persulfate can accelerate the photocatalytic reaction rate to a certain extent,while alcohols and iodide ions can significantly inhibit the photocatalytic reaction.The effects of bicarbonate and sulfate ions on the photocatalytic reaction system is very limited.