稀土掺杂TiO_2光催化还原CO_2

Rare earth doped TiO_2 catalysts for CO_2 photocatalytic reduction

采用溶胶-凝胶法制备了稀土掺杂TiO2纳米光催化剂,并应用于光催化还原CO2/H2O体系中。通过XRD对光催化性能进行表征,研究稀土离子掺杂和焙烧温度对光催化性能的影响。结果表明,稀土La和Ce的加入可以抑制TiO2的晶相转变,提高光催化性能。催化剂800℃焙烧可达到最好的光催化活性,在反应时间7 h、CO2流量200 mL·min-1和反应液中NaOH与Na2SO3浓度均为0.10 mol·L-1条件下,甲醇产率高达315.49μmol.g-1。并对稀土掺杂TiO2催化剂光催化还原CO2的机理进行了探究。

TiO2 nanometer photocatalysts doped with rare earth were prepared by sol-gel method and were used for the photocatalytic reduction of CO2 in water. The catalysts were characterized by XRD technology. The effects of rare earth ion doping and calcination temperature on photocatalytic activity of the catalysts were investigated. The results showed that the addition of rare earth La and Ce could effectively inhibit phase transformation of TiO2 and enhanced the photocatalytic performance ; the catalyst calcined at 800 ℃ exhibited the best catalytic activity. Methanol yield of 315.49 p.mol · g-1 was attained under the optimal reaction condition as follows：reaction time 7 h, CO2 flow rate 200 mL ·min- 1, and both concentration of NaOH and NaESO3 0.10 mol · L-1. The mechanism of CO2 photoeatalytic reduction on TiO2 catalyst doped with rare earth was put forward.