摘要
介绍了一种将TiO2光催化剂担载在新型载体上的光催化电极.新型载体是用炭质材料和聚四氟乙烯制备的,它具有电合成H2O2的功能.在电流密度为15mA/cm2时,光催化电极不仅具有高达80%的电合成H2O2的电流效率,而且该电极的电位处在0.02V(SCE)左右,使载体表面的TiO2光催化剂获得了约+0.47V的阳极偏压(相对平带电势),对增加TiO2光催化反应效率十分有益.在具有新型光催化电极的光反应体系中,水中的有机分子受到来自溶液中大量·OH自由基(H2O2被紫外光分解的中间产物)的均相氧化(即光化学氧化),以及来自TiO2表面光生空穴的复相氧化(即光催化氧化).在光化学氧化和光催化氧化的联合作用下,有机分子的矿物化反应速度显著提高.
A photocatalytic electrode with TiO_2 immobillized on the new supporter was reported.The new supporter which was prepared using carbon and polytetrafluoroethylene (PTFE) has the function of electrogenerating H_2O_2.Under 15 mA/cm^2,the photocatalytic electrode not only had the current efficiency of synthesizing H_2O_2 of 82%,but its potential (about 0.02 V(SCE)) made a TiO_2 on the supporter obtain +0.47 V anodic bia (VS.flat band potential)which was very profitable for increasing efficiency of photocatalytic reaction.So,in a photo-reactor with the photocatalytic electrode,mineralization rate of the organic compounds was greatly enhanced due to joint effect of the homogeneous oxidation of the organic moleculars by ·OH from photodissociation of H_2O_2 in the solution(oxidation of photochemistry)and heterogeneous oxidation by holes at TiO_2 (Photocatalytic oxidation).
出处
《感光科学与光化学》
CSCD
北大核心
2004年第3期161-168,共8页
Photographic Science and Photochemistry
基金
国家自然科学基金(20071026).
关键词
光催化电极
TIO2
载体
降解
苯甲酸
photocatalytic electrode
TiO_2 supporter
degradation
benzoic acid
