Ag-Mg tandem sites co-modified ultrathin ZnO achieving adsorption and activation synergistic effects for light–driven methane selective conversion

Direct light-driven methane selective conversion into useful chemicals remains a major challenge due to the need for photocatalysts with high photoactivity and selectivity in activating inert C-H bonds. In this study, we have developed highly photoactivity and selective photocatalytic CH 4 oxidation into C 2 H 6 using Ag-Mg tandem sites co-modified ultrathin ZnO hybrid photocatalysts in a flow reactor. Our system achieves an C 2 H 6 production rate of over 1860  μmol/g/h with 93 % selectivity, which is significantly higher than the efficiency of state-of-the-art photocatalytic systems. Various in-situ characterizations and theoretical studies reveal that the Ag-Mg tandem sites co-modified leads to enhanced photogenerated charge separation efficiency, while maintaining high ethane production rate owing to the strong selective adsorption capacity for methane and oxygen of the doped Mg sites and oxygen vacancy. Furthermore, the Ag nanoparticles cocatalyst can facilitate the removal of activated CH 4 in the form of methyl radicals in the gas phase, thereby promoting C 2 H 6 formation and inhibiting CH 4 overoxidation to produce CO 2 . Overall, these findings provide novel insights into the photocatalytic conversion of CH 4 on Ag/Mg-ZnO. These results offer valuable possibilities for developing more effective catalysts for the conversion of CH 4 to higher value-added products.