CO2在TiO2-CuO修饰Cu电极上的光电化学还原  

Photoelectrochemical Reduction of CO_2 on TiO_2-CuO/Cu Composite Electrode

作　　者：徐冠华 吴新平 刘洪涛[2] 朱果逸[3] 

机构地区：[1]八一钢铁厂新冶华美科技有限公司,乌鲁木齐830022 [2]中南大学化学化工学院,长沙410083 [3]中国科学院长春应用化学研究所,长春

出　　处：《应用化学》2009年第4期475-478,共4页Chinese Journal of Applied Chemistry

摘　　要：制备了TiO2-CuO修饰Cu电极,并对CO2在该复合光电电极上的还原行为进行了研究。光电化学测试表明,TiO2有助于电极的光电转换,能注入更多的电子促进CO2还原。TiO2-CuO/Cu复合电极在光照条件下对CO2具有很好的光电催化还原活性,使还原电位正移约100 mV,同时有效地抑制了水的光电分解。Mott-Schottky曲线测定表明,TiO2-CuO/Cu复合电极具有n型半导体性质,其平带电位随光照时间的增加而负移。光谱及色质谱测试证明,CO2在TiO2-CuO/Cu复合电极上的光电化学还原产物为甲酸和甲醛,还有少量乙烯和甲烷。在-1.2 V条件下光照3 h,CO2的转化率可达32%。基于实验结果对CO2光电还原机理进行了推断。TiO2-CuO/Cu composite electrode was fabricated and used to investigate the photoelectrochemical reduction of CO2.The photoelectrochemical measurements show that TiO2 could effectively absorb light energy and release abundant electrons to enhance the reduction of CO2.The TiO2-CuO/Cu composite electrode has a good catalytic activity for reducing CO2 under light radiation.The onset reduction potential was shifted positively from-0.9 V to-0.8 V,and at the same time,the decomposition of water was greatly suppressed.The Mott-Schottky profiles showed the composite electrode was n-type semiconductor and the flat-band potential was shifted negatively as the radiation time increased.The FT-IR and GC-MS spectroscopies proved the reducted products were mainly HCOOH and HCHO,along with a small amount of CH4 and C2H4.At-1.2 V for 3 h under light radiation,the conversion rate for CO2 reached to 32%.Based on the experimental data,the free radical reduction mechanism was proposed.

关 键 词：复合电极 CO2 光电化学 还原机理 

分 类 号：O641[理学—物理化学]