Study On The Preparation Of TiO₂ Graphene Composite Catalyst And Its Photocatalytic Degradation Of Methylene Blue

TiO₂ photocatalytic technology has been widely used and studied due to its high efficiency,no pollution and high degree of mineralization.But the photocatalytic performances of TiO₂ photocatalytic technology were weaken,for example,weak enrichment ability,non-reuse catalyst,and recombination of photogenerated hole-electronic,etc.Graphene with good characteristics can greatly improve the performance of titanium dioxide existing problems,so the preparation of titanium dioxide/graphene composite photocatalyst has become a hot topic.Two types of titanium dioxide/graphene composite catalysts were synthesized by using tetrabutyl titanate?TBT?and the graphene oxide?GO?in Hummer‘s method as precursors through hydrothermal method,and here,are denoted as TiO₂-RGO?l?and TiO₂-RGO,respectively.The main crystal structure of the two kinds of composites was anatase;The band gap of TiO₂-RGO?l??2.8 eV?was slightly lower than the TiO₂-RGO?2.9 eV?;Meanwhile,the specific surface area of TiO₂-RGO?l?system?154.6252 m2/g?was slightly higher than that of TiO₂-RGO system?137.587 m2/g?,which were significantly higher than that of pure titanium dioxide?87.5193 m2/g?.The experimental results showed that the photocatalytic degradation on methylene blue?MB?of the two kinds composite materials were more efficient than those of TiO₂,and TiO₂-RGO?l?composite photocatalytic performances were better than TiO₂-RGO under different proportion of precusors.So graphene oxide?GO?in liquid form was effectively compositing with TBT,showing higher photocatalytic activity.On the basis of above research,the manuscript took TiO₂-RGO?l?system of composite photocatalyst as the research object,and the methylene blue?MB?as the target of pollutants.The study of the preparation proportion and the initial pH of the solution on degradation of methylene blue?MB?showed that its photocatalytic performances is best when the ratio of TiO₂ and GO is 1:0.06,and its reaction rate constant was nearly 2 times higher than that of titanium dioxide.Photocatalytic degaradation rate increased from 38% to 78.7% when the pH increased from 2 to 9.46,and the first order kinetics reaction rate constant k has increased 3.7 times;Loading the composite material?M?on polypropylene?PP?,it is found that the degradation of MB was best when the ratio of PP and M was 5:5.after reused seven times of the catalyst,the photocatalytic degaradation of MB reduced from 86.4% to 78.5%.TOC removal during he photocatalytic process was lagging behind,and the removal efficiency reached 93% after 5h of reaction.