A highly efficient and stable TiO2@NH2-MIL-125 material for enhanced photocatalytic conversion of CO2 and CH4
Yufei Huang, Wei Ding, Ziyi Li, Yu Mao, Yangqiang Huang, Bo Jin, Xiao Luo, Zhiwu Liang
Abstract
At present, there are many difficulties in accomplishing the effective and efficient chemical utilization of CO 2 , such as low catalyst stability, high energy consumption, limited conversion of CH 4 by reforming due to thermal reaction kinetics, high reaction temperature and high demand on reactor material. Here, a novel composite catalyst TiO 2 /NH 2 -MIL-125, prepared by three different methods, was applied to the photocatalytic conversion of CO 2 with CH 4 under visible-light irradiation. The experimental results showed that NH 2 -MIL-125@TiO 2 -40 catalyst prepared by ultrasonic impregnation method achieved rapid conversion of CO 2 and CH 4 at room temperature, and the yield of CO was up to 159 μ mol/g, which was 510% great than the catalytic performance of TiO 2 . In addition, the photocatalytic reduction efficiency of NH 2 -MIL-125@TiO 2 -40 material held stay at 93.7% after continuous operation for 28 h, showing excellent photocatalytic stability. Moreover, a series of characterization techniques were used to study the structure, morphology and photoelectric chemical properties of the photocatalyst. As well, the relationship between the physical and chemical properties of the material and the catalytic performance of CO 2 conversion is discussed. Based on the above studies, a possible catalytic mechanism for the photocatalytic conversion of CO 2 by NH 2 -MIL-125@TiO 2 hybrid materials is proposed.