Ag-AgCl biphasic composite as efficient co-catalyst for photocatalytic oxidation of CH4

Photocatalytic oxidation of methane (CH 4 ) to value-added chemicals offers a sustainable and promising approach for chemical synthesis, however, efficient catalysts for the activation of inert C H bonds remain challenging. Herein, a novel Ag-AgCl biphasic composite was used as co-catalysts to modify ZnO semiconductor (Ag-AgCl/ZnO-z). Structure properties and catalytic performance in photocatalytic oxidation of CH 4 of the sample were systematically investigated, together with comparison with pure ZnO (ZnO-z) and a single Ag modified counterpart (Ag/ZnO-z). It was found that Ag-AgCl/ZnO-z was enriched with heterogeneous interfaces, which facilitated ultrafast carrier transport and their prolonged separation. Interestingly, AgCl acted as a hole acceptor, and the lattice Cl can be directly activated to •Cl, which is then responsible for forming a new •CH 3 formation pathway via a hydrogen atom transfer (HAT) mechanism. Moreover, a Cl-looping process can be established so that the catalyst remained stable during cyclic reactions. Under the optimum conditions, an excellent liquid oxygenates productivity of 12,731 μmol·g −1 ·h −1 was achieved. This work presents a prototype for designing biphasic composite co-catalysts, thereby offering valuable insights into introducing multiple CH 4 activation pathways.