Solar-driven efficient methane catalytic oxidation over epitaxial ZnO/La0.8Sr0.2CoO3 heterojunctions

Gas flaring in oil/gas drilling and gas leakage in natural gas power plant lead to significant energy loss and environmental burden. Here, solar-driven efficient methane oxidation was demonstrated under high velocity continuous flow over the ZnO/La0.8Sr0.2CoO3 (ZnO/LSCO) heterojunctions. The ZnO/LSCO heterojunctions enable a unique epitaxial hetero-interface, which effectively regulates the electron transfer between Zn 3d-O 2p hybrid orbital in ZnO and Co eg orbital in LSCO and promotes the rapid generation and refill of oxygen vacancy with unpaired electron (Vo), thus enhancing the activity and mobility of surface lattice oxygen in ZnO/LSCO. Under solar illumination, the synergy of photothermal and photocatalytic effect boosts the reversible electron transfer in the interface, which further activates surface lattice oxygen, resulting in a ∼2 times higher methane oxidation activity. Such a solar-driven system not only enables a promising pathway for emitted methane utilization, but also provides an advanced catalyst design concept of epitaxial interface construction.