活性炭负载Cu离子掺杂纳米TiO_2颗粒的制备及光催化性能

Preparation and Photocatalytic Properties of Activated Carbon Supported TiO_2 Nanoparticles with Cu Ions Doping

采用溶胶-凝胶法在活性炭(AC)表面负载掺杂Cu离子的TiO2纳米颗粒,制备负载型掺杂Cu2+-TiO2/AC复合光催化剂,采用XRD,ESR,FS,UV-Vis和BET等手段对其进行了表征,通过罗丹明B的光催化降解试验,分析活性炭载体的比表面积和Cu离子掺杂量对负载型掺杂催化剂光催化活性的影响.结果表明,Cu以+2价存在,Ti以少量的+3价存在;TiO2纳米颗粒具有量子尺寸效应,吸光阈值显著蓝移,并使光谱相应范围向可见光区拓展;另外,适量Cu离子的掺杂降低了负载型TiO2/AC的荧光强度.负载和高温处理没有改变活性炭载体的微观结构.以AC3为载体和质量分数为3%的Cu离子掺杂所制备的3%Cu2+-TiO2/AC催化剂的活性最高,并且该催化剂便于回收,在重复使用中也表现出很高的光催化活性.

Composite photocatalysts（ Cu^2＋-TiO2/AC） were prepared via a sol-gel method by means of activated carbon（AC） supported TiO2 nanoparticles with copper ions doping. The photocatalysts were characterized by XRD, ESR, FS, UV-Vis and BET analysis. The effects of specific surface area of AC and amount of Cu ions doping on the photoactivity of the as-prepared samples were analyzed by photodegradation of Rhodamine B （RB）. The results show that Cu ions exist in a form of the Cu^2＋ ions and there are a few of Ti^3＋ ions state in titanium dioxide. The TiO2 nanoparticles show the quantum size efficiency, the notablely blue shifting of absorption threshold and the optic response range expanding to visual light. Additionally, the FS intensity of TiO2/AC decreases via proper amount of Cu ions doping. The microcosmic structure of AC is changed by coating and heat treatment at a high temperature. Photocatalysts（3% Cu^2＋ -TiO2/ACa ） show the highest photoac- tivity by using AC3 as the carrier with 3% Cu^2＋ ions doping, meanwhile, they can be easily recovered from the reaction solution and reused with a high photoactivity.