Preparation And Study Of TiO₂Hollow Microspheres Assembled By Nanorods

Titanium dioxide (TiO2) is a good material for solving environmental problembecause of its good photocatalysis, which can degrade organic pollutants efficiently.However, it still has several defects, among which the most restrictive one is the need ofusing an ultraviolet (UV) light as excitation source due to its wide band-gap. Therefore,it can only capture less than5%of the solar irradiance at the Earth’s surface. In addition,the photogenerated electron-hole pair recombines easily resulting in poor photocatalyticactivity; In the course of actual use, the nano TiO2occur aggregation problem easily andit is difficult to be recycled. Therefore, it is significant to improve its photocatalyticperformance and solve the problem of aggregation and difficult recycle. In this article,we provide a novel vesicle template method to synthesize TiO2hollow microsphereswhich are self-assembled with uniform1-D TiO2nanorods. We studied the factors ofpreparation, structure, adsorptive and photocatalytic performance.In this work, TiO2hollow microspheres were successfully prepared by a novelvesicle template method. The study shows that TiO2hollow microspheres are crosswiseself-assembled with uniform1-D TiO2nanorods and the diameter of microspheres isabout1~2μm. Moreover, TiO2hollow microspheres possess mesoporous surface andtheir specific surface area is about242m2/g. We studied the influential factors of hotpressing temperature, hot pressing time and template agent. The results indicate that thecomplete nanorods surface is formed when hot pressing temperature is controlled at180°C and hot pressing time is at24h. Polyethylene glycol (PEG) is the key of theformation of TiO2nanorods. Tween and PEG jointly formed vesicle template to formhollow structure of the microspheres.In this paper, the adsorption performance of TiO2hollow microspheres was studiedby adsorption isotherms model and adsorption kinetics model. Results shows that TiO2hollow microspheres have higher adsorption capacity and faster adsorption rate compared with TiO2solid microspheres. The maximum adsorption capacity is up to196.83mg/g. In addition, the adsorption process and mechanism of TiO2hollowmicrospheres was investigated.In this article, comparing with the commercial TiO2(P25), the photocatalyticproperties and photocatalytic stability of TiO2hollow microspheres on methylene bluewas studied. It was found that TiO2hollow microspheres showed a good photocatalyticperformance and photocatalytic stability. In addition, we make a preliminary study onthe adsorptive and photocatalytic collaborative applications of TiO2hollowmicrospheres, which can be a good reference for TiO2recycle.