摘要
采用沉淀法和溶胶 -凝胶法制备了 Zn O和 Ti O2 及掺 Zn2 + 的 Ti O2 纳米粒子 ,用 XRD和荧光光谱 (FS)等手段对样品进行了表征 ,重点探讨了样品光致发光机制及与光催化活性的关系 .结果表明 ,Zn O和 Ti O2样品在大于带隙能的光激发下均表现出明显的 FS信号 ,热处理温度升高 ,FS信号强度下降 ,并且二者的FS信号类似 ,这可能与二者具有类似的电子能带结构有关 ,同时也说明 FS信号主要源于表面氧空位以及吸附氧物种等引起的激子或表面态能级 .掺杂 Zn2 +使 Ti O2 纳米粒子 FS信号增强 ,这主要与表面氧空位和缺陷等量增加有关 ;此外 ,在光催化氧化苯酚实验中 ,样品光催化活性与其 FS信号强度顺序一致 ,即 FS信号越强 ,活性越高 .这是由于在光致发光过程中 ,FS信号主要源于表面氧空位 ,而在光催化反应中 ,表面氧空位有利于氧化反应进行 .
In this paper, ZnO, TiO 2 and Zn 2+ doped TiO 2 nanoparticles were prepared by chemical precipitation and sol-gel method, respectively, and characterized by means of XRD and FS spectra. We mainly investigated the relationships between the photoluminescence performance and photocatalytic activity of the as-prepared samples as well as the photoluminescence mechanism. The results show that ZnO and TiO 2 nanoparticles exhibit obvious FS signals by excitation with the light of higher energy than band-gap energy, and the intensity of FS signals decreased with increasing the temperature of thermal treatment. It should be pointed that the FS signal structure of ZnO and TiO 2 samples are similar, which was possibly related to their similar structure of electronic energy band. It could be demonstrated that FS signals are mainly originated from the energy level of exciton and surface states resulting mainly from surface oxygen vacancies and adsorbed oxygen species. Zn 2+ dopant made the FS intensity of TiO 2 nanoparticle increase, due to the increase in the content of surface oxygen vacancies and defects. In addition, during the experiment of photocatalytic oxidation of phenol, the orders of the photocatalytic activity of as-prepared samples were the same as that of the FS intensity, namely, the stronger the FS intensity, the higher the activity. This was the reason that FS spectra mainly resulted from the surface oxygen vacancies during the photoluminescence process, while surface oxygen vacancies were favourable for the photocatalytic oxidation reaction.
出处
《高等学校化学学报》
SCIE
EI
CAS
CSCD
北大核心
2005年第1期111-115,共5页
Chemical Journal of Chinese Universities
基金
国家自然科学基金(批准号:20171016
20301006
20431030)
黑龙江省自然科学基金(批准号:B0305)
黑龙江省普通高等学校骨干教师创新能力资助计划(批准号:1054G035)
中国博士后科学基金(批准号:20040350168)
黑龙江省2002年度杰出青年基金
黑龙江大学2003年度杰出
