Unveiling mechanistic insight into boosting oxygen species activation over CeO/MnO p-n heterojunction for efficient photothermal mineralization of toluene.

The activation mechanism of oxygen species activation (including lattice oxygen and gaseous oxygen) in the photothermal catalytic reaction process is important for boosting the efficient removal of VOCs. Herein, we have successfully synthesized a p-n heterojunction photothermal catalyst CeO/MnO for exploring the activation of molecular oxygen and lattice oxygen in toluene catalytic reaction under full spectrum conditions. Various characterization tests and theoretical calculations showed that the formed composite has enhanced light absorption ability, oxygen species migration and transformation ability as well as nice redox cycles, which is conducive to the fast replenishment of surface lattice oxygen and continuous capture and activation of molecular oxygen. Meanwhile, the results of in-situ DRIFTS tests not only confirmed the enhanced activation process of surface lattice oxygen and molecular oxygen under the synergistic effect of light and heat, but also revealed the pathway and mechanism of photothermal catalytic toluene over CeO/MnO.