Ag负载对N掺杂TiO_2薄膜光催化性能的影响

Effect of Silver Deposition on Photocatalytic Performance of N-Doped TiO_2 Thin Film

采用电泳沉积法在Ti片上制备TiN薄膜,在450℃下保温60min制备N掺杂TiO_2薄膜(N-TiO_2薄膜),然后在不同浓度的AgNO3溶液中利用光还原沉积法制备负载Ag的N-TiO_2薄膜。利用X射线衍射(XRD)、扫描电子显微镜(SEM)和紫外-可见吸收光谱(UV-Vis)对薄膜进行表征,通过测试瞬态光电流密度研究薄膜的光电性能,并以罗丹明B为降解目标物评价薄膜的光催化活性,重点研究了负载Ag对N-TiO_2薄膜光电和光催化性能的影响规律。结果表明:AgNO_3溶液浓度为0.05mol·L-1时,Ag的负载量最为适宜,N-TiO_2薄膜的光电及光催化性能最佳;负载Ag的N-TiO_2薄膜在可见光下的瞬态光电流密度约为N-TiO_2薄膜的5.4倍;负载Ag显著提高了N-TiO_2薄膜的光催化性能,经过可见光照射180min后,薄膜对罗丹明B的降解率达到98%。

Titanium nitride（TiN）thin film was prepared by electrophoreic deposition process on Ti substrate in an aqueous suspension of nanosized TiN powder,and then nitrogen-doped titanium dioxide（N-TiO_2）thin film was fabricated by heating the TiN film at 450 ℃for 1hin air.Ag nanoparticles were deposited on the surface of N-TiO_2 thin film in different concentration of AgNO3 solution by photo-reduction deposition.The samples were characterized by X-ray diffraction,scanning electron microscopy and UV-visible spectroscopy.Photoelectric properties and photocatalytic activities were investigated via the measurement of transient photocurrent density and the photocatalytic degradation of Rhodamine B under visible light,respectively.Effect of silver deposition on photoelectric and photocatalytic performance of N-TiO_2 thin film was emphatically studied.The results show that moderate deposition of Ag particles significantly improved the photoelectric and photocatalytic performance of N-TiO_2 thin film,and the optimal concentration of AgNO_3 solution for Ag deposition was 0.05mol·L^（-1）.Under visible light,the transient photocurrent density of Ag deposited N-TiO_2 thin film was approximately 5.4times that of N-TiO_2 thin film,and for Ag deposited N-TiO_2 thin film,the degradation rate of Rhodamine B for 3hours was 98%,improved a lot when compared with that of N-TiO_2 thin film.