摘要
采用直流电压法将P25型TiO2粉末负载于FTO导电玻璃制成半导体矿物电极,研究其在不同小分子有机物(甲酸、甲醇、乙酸、乙醇)、不同浓度(0、20、40、60、80、100mmol/L)甲酸作为空穴捕获剂下对U(Ⅵ)的光催化还原。研究结果表明,由于电离能力的强弱不同,酸类小分子有机物对空穴的捕获能力强于醇类小分子有机物,添加的小分子有机物均能提高U(Ⅵ)的还原率且甲酸效果最好,添加60mmol甲酸光催化反应4h后,U(Ⅵ)的还原率能达到90.26%。扫描电镜(SEM)及能谱(EDS)分析表明,反应后电极表面有大颗粒方块状U(Ⅳ)的矿物生成,占据反应活性位点。电化学阻抗分析显示,反应后电极传递电子的阻力增大,电子传输能力减弱,催化活性降低。
The TiO2（P25）semiconductor mineral electrode was used to study the photocatalytic reduction of U（Ⅵ）with low-molecular-weight organics（formic acid,methanol,acetic acid,ethanol）and formic acid at different concentrations（0,20,40,60,80,100mmol/L）as hole scavengers,respectively.The results indicate that due to the higher ionizing ability,the hole scavenging capacity of low-molecular-weight organic acid is stronger than that of low-molecular-weight alcohol.In addition,all hole scavengers studied in this paper can improve the reduction rate of U（Ⅵ）and formic acid is best with the reduction rate as high as90.26% at 60mmol/L.SEM and EDS results show that some squares of uranium minerals were formed after photocatalytic reaction,which were adsorbed on the electrode surface and occupied active sites of TiO2.Electrochemical impedance spectroscopy（EIS）analysis indicates that mineral semiconductor electrode exhibits a higher electron transport resistance ability after photocatalytic reaction.
出处
《核化学与放射化学》
CAS
CSCD
北大核心
2017年第1期30-35,共6页
Journal of Nuclear and Radiochemistry
基金
国家重点基础研究发展计划资助项目(973计划
2014CB846003)
西南科技大学研究生创新基金资助项目(16ycx043)
关键词
小分子有机物
P25
U(Ⅵ)
电化学阻抗
空穴捕获剂
low-molecular-mass organics
P25
U（Ⅵ）
electrochemical impedance spectros copy
hole scavenge
