Dual-function ZnO/CeO₂ photocatalyst for simultaneous methane decomposition and CO₂ adsorption at room temperature

Climate change mitigation urgently requires innovative approaches to address multiple greenhouse gases simultaneously. This study introduces a novel ZnO/CeO₂ composite photocatalyst that demonstrates high efficiency in methane decomposition under ambient conditions, while also exhibiting CO₂ capture capabilities. Synthesized via an oxalate-based co-precipitation method, the ZnO/CeO₂ composite achieved near-complete methane decomposition (from 100 to 4 ppm) within 180 min of UV irradiation at room temperature and ambient pressure. Notably, the ZnO/CeO₂ composite showed significantly enhanced methane adsorption capacity compared to pure ZnO or CeO₂, which directly contributed to its superior methane decomposition performance. This increased adsorption ability, combined with efficient charge separation at the ZnO/CeO₂ interface, facilitates the rapid and effective decomposition of methane molecules. Furthermore, the composite exhibited simultaneous CO₂ adsorption capacity. The CO₂ generated from the methane decomposition was largely adsorbed by the ZnO/CeO₂ composite, as evidenced by the low detection of CO₂ in the gas phase during the reaction. This dual functionality of enhanced methane decomposition and subsequent CO₂ capture represents an integrated approach for greenhouse gas reduction. This work not only advances the field of greenhouse gas mitigation but also introduces a new paradigm for designing multifunctional environmental remediation materials.