Ti(SO_4)_2水热法制纳米SO_4^(2-)/TiO_2光催化剂的光谱研究

Spectral Studies on Nano-sized SO_4^(2-)/TiO_2 Photocat alyst Prepared by Hydrothermal Heating the Solution of Ti(SO_4)_2

以Ti(SO4) 2 水溶液为前驱物 ,尿素为沉淀剂 ,采用水热沉淀 加热分解 浸渍烧结法制备纳米SO2 -4/TiO2 固体超强酸光催化剂 ,并用XRD ,BET ,FTIR ,DRS和FS等对中间态粒子和产物进行表征 ,以光催化降解罗丹明B为模型反应 ,筛选制备SO2 -4/TiO2 光催化剂的优化条件。结果表明 ,用Ti(SO4) 2 为前驱物 ,水热法能在较低的温度、弱碱性介质中 ,得到纳米锐钛矿型TiO2 晶体 ;在 30 0℃下控制焙烧 4h ,基本能使水热反应副产物 (NH4) 2 SO4等分解 ,又避免H2 SO4大量的流失 ;SO2 -4负载量和烧结时间是影响SO2 -4/TiO2 光催化活性的主要因素 ,当SO2 -4负载量 11%、烧结温度 4 5 0℃时 ,制备的SO2 -4/TiO2 光催化剂活性较高 ,达P 2

In this paper,the nano-sized SO^2- -4/ Ti O_2 solid superacid photocatalysts have been prepared by the method of hydrothe rmal heating the mixed solution of Ti(SO_4)_2 and urea,heating-decomposing, wet impregnating-calcining. The middle products and the ultimate produc ts have been characterized by XRD,BET,FTIR,DRS and FS. The degradation of rhodamine B by photocatalyst was regarded as a model reaction. The optimum condition of pre paring SO^2- _4/ TiO_2 photocatalysts has been chosen. The results show t h at hydrothermal treating the solution of Ti(SO_4)_2 can get the anatase nano- sized TiO_2 in the weak alkalinity medium;at 300℃ by-products of hydroth erma l reaction,such as (NH_4)_2SO_4 and so on,can be decomposed by calcining fo r 4 hours,avoiding much loss of H_2SO_4;the most important factors that imfl uence the photocatalystic activities of SO^2- _4/ TiO_2 are the concentra t ion of SO^2- _4 on TiO_2 and the calcination time. SO^2- _4/ TiO_2 p hotocatalysts have the best photocatalystic activities,up to the level of P-25 photocatalyst,when the concentration of SO^2- _4 on TiO_2 is 11% and the calcination temperature is 450℃.