The TiO2 nano particles were synthesized by using the similarmethod. Firstly, the precursor materials were prepared by usingelectrospray and the PVP amount used was 0.7 g; secondly, the sprayed materials were mixed with ethanol, water, and aceticacid to undergo a strong stirring for more than 2 h; thirdly, the sample was put in an autoclave for hydrothermal reaction at160◦C for 24 h.