The Preparation Of TiO₂ And Its Composites Photocatalyst In Deep Eutectic Solvent And Their Photocatalytic Properties

Presently,photocatalysis has been considered as one of the most effective methods to dissolve the organic pollution for water and air.At present,many semiconductors have been successfully explored for photocatalysts.Among these materials,TiO2 nanoparticles,possessing high photocatalytic activity,good stability,non-toxic harmless and so on,have been paid more and more attention.However,the aggregation and difficult separation limits the practical application for TiO2 nanopartilces in many fields.To solve these shortcomings,fabrication of micro-zide TiO2 spheres composed of nano-sized particles was an efficient way.TiO2 microspheres with large specific surface area faceilate the adsorption for organic pollutants and give enhanced photocatalytic performance,when they were used as photocatalysts.Until now,it is still challenge to synthesize TiO2 micropheres and investigate their photocatalytic properties.In this paper,TiO2 and ZnO/TiO2 microspheres have been prepared via a simple emulsion method.In this case,tetrabutyl titanate(TBT)was used as both Ti source and oil phase,whereas the deep eutectic solvent(DES)were used as the aqueous phase.The effects of the experimental conditions on the structures for the products have been thoroughly studied and the possible formation mechanism has been proposed.The obtained materials could be used as photocatalysts to degradate reactive brilliant blue(KN-R).In this paper,two types of deep eutectic solvents were used as the aqueous phsed during the preparation process,respectively.It is found that the mounts of water addition,reaction temperature,reaction time,stirring speed and calcination temperature play important roles on the structure of TiO2 samples.Additionally,the photocatalytic activity of TiO2 microspheres was signigicantly influenced by the calcination temperature.Our results show that when the ratio of TBT and H2O is in the range of 1:4-1:12,the stirring speed is in the range of 500-1500 r/min,and the stirring time is more than 15 minutes,TiO2 microspheres composed of a large number of irregular TiO2 particles could be obtained.The reaction temperature and time hardly affects the structure of TiO2.The anatase TiO2 microspheres with high crystallinity were obtained after calcinations treatment at 450 ℃.It should be noting that ZnO/TiO2 microspheres possess better photocatalytic activity than that of TiO2 microspheres due to the introduction of ZnO.