Synergizing Multiple Active Sites for Boosting Activity and Inhibiting Overoxidation in Photocatalytic Methane Valorization

The pursuit of ecofriendly methane utilization has prompted the innovation of photocatalytic techniques to convert methane into profitable chemicals while achieving zero-waste output. However, the readily formed overoxidized products pose a significant challenge due to the oxidation by lattice oxygen in catalysts. To overcome this challenge, we have proposed a strategy of synergizing multiple active sites by integrating Ag nanoparticles and ZnIn₂S₄ nanosheets onto ultrathin Ti(HPO₄)₂. The formed Ti(HPO₄)₂/ZnIn₂S₄ heterojunction promotes the formation of active Ti³⁺ sites induced by photogenerated electrons, while the synergistic interaction between Ti³⁺ sites (methane adsorption centers), lattice oxygen (activation sites), and Ag nanoparticles (methyl desorption sites) boosts activity and inhibits overoxidation in methane conversion. The constructed photocatalyst demonstrates a remarkable 98% selectivity for ethane production at a rate of 280 μmol·g^–1·h^–1, accompanied by stoichiometric hydrogen production. This work highlights a strategy of synergizing multiple active sites for designing photocatalysts for methane valorization.