Visible-light-enhanced photothermocatalytic activity of ABO3-type perovskites for the decontamination of gaseous styrene

Abstract

ABO3-type perovskites (A=La, Ce, Sm; B=Cr, Mn, Fe, Co, Ni) were systematically fabricated via a facile soft-templated sol-gel with post-calcination method through a complexation-carbonation-oxidation process, which were successfully applied in the visible-light-driven photothermocatalytic degradation of volatile organic compounds (VOCs) for the first time. Preliminary characterization results revealed the lower impact to the oxidative performance and visible-light-absorption properties of ANiO3 than LaBO3, while the latter ones should present more attractive promotion of catalytic performance toward VOC degradation. Subsequently catalytic degradation of VOCs using gaseous styrene as model compound confirmed that all LaBO3-type perovskites possessed both high visible-light-driven photocatalytic and temperature-induced thermocatalytic activities. Meanwhile, synergetic effect between photocatalysis and thermocatalysis activities of different position B substituted LaBO3 resulted in different enhancement of their photothermocatalytic activities, where the highest synergistic factor (3.53) was obtained for LaMnO3 at 140°C. Besides, the synergetic effect could also effectively preserve the activity of the perovskite catalysts (eg. LaMnO3) that almost the same removal efficiency (ca. 96.6% within 40min) was obtained to styrene (initial concentration of 40ppmv) after five continuous cycling tests. The highly and stably photothermocatalytic activity of these perovskites were attributed to the coefficient effect of the small crystal size and narrower bandgap as well as high visible light absorption and reducibility. This work could provide an efficient and practical way to utilize the total energy of sun for the remediation of atmospheric environment pollutions.