Photothermocatalytic performance of ACo(2)O(4) type spinel with light-enhanced mobilizable active oxygen species for toluene oxidation |
Chen, X (Chen, Xi); Cai, SC (Cai, Songcai); Yu, EQ (Yu, Enqi); Li, JJ (Li, Juanjuan); Chen, J (Chen, Jing); Jia, HP* (Jia, Hongpeng) |
Recently, photo-thermocatalysis has been intensively motivated since it is beneficial for both relieving energy consumption and using the full solar spectrum energy. In this work, efficient photo-promoted thermocatalytic removal of VOCs has been investigated on ACo2O4 (A = Ni, Cu, Fe, Mn) spinel by harvesting inexhaustible solar energy to provide thermal energy. ACo2O4 was synthesized by co-precipitation method, which exhibits strong light absorption in the entire solar spectrum (200–2500 nm) and high solar heating effect, providing enough thermal energy for catalytic degradation of toluene. The photo-thermocatalytic performance of ACo2O4 catalysts follows the sequence: NiCo2O4 > CuCo2O4 > FeCo2O4 > MnCo2O4, in which NiCo2O4 exhibits the highest photo-thermocatalytic activity (93% for toluene conversion and 80% for CO2 yield) and good stability (at least for 20 h) for toluene oxidation under irradiation. And such excellent light-driven catalytic performance over NiCo2O4 can be mainly explained by its strong light absorption, high photo-thermal conversion, more active oxygen species, enlarged surface area and the better OCS. Besides, a novel light-enhanced effect is revealed to considerably increase the photo-thermocatalytic activity for toluene oxidation, which is quite different from the traditional photocatalysis. By combining CO temperature-programmed reduction (CO-TPR) and in situ diffuse reflectance infrared Fourier transform spectroscopy (in situ DRIFTS), it is revealed that the irradiation is able to enhance the mobility of active oxygen species, resulting in a significant improvement of photo-thermocatalytic activity over NiCo2O4.
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Key words:Spinel; VOCs; Defects; Photo-thermocatalysis; Light-enhanced effect |
Volume:484 Page:479-488 Journal:APPLIED SURFACE SCIENCE |
https://doi.org/10.1016/j.apsusc.2019.04.093
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