High-rate CH 4 -to-C 2 H 6 photoconversion enabled by Au/ZnO porous nanosheets under oxygen-free system

Photocatalytic CH 4 coupling into high-valued C 2 H 6 is highly attractive, whereas the photosynthetic rate, especially under oxygen-free system, is still unsatisfying. Here, we designed the negatively charged metal supported on metal oxide nanosheets to activate the inert C–H bond in CH 4 and hence accelerate CH 4 coupling performance. As an example, the synthetic Au/ZnO porous nanosheets exhibit the C 2 H 6 photosynthetic rate of 1,121.6 µmol g cat −1 h −1 and the CH 4 conversion rate of 2,374.6 µmol g cat −1 h −1 under oxygen-free system, 2 orders of magnitude higher than those of previously reported photocatalysts. By virtue of several in situ spectroscopic techniques, it is established that the generated Au δ− and O − species together polarized the C–H bond, while the Au δ− and O − species jointly stabilized the CH 3 intermediates, which favored the coupling of CH 3 intermediate to photosynthesize C 2 H 6 instead of overoxidation into CO x . Thus, the design of dual active species is beneficial for achieving high-efficient CH 4 -to-C 2 H 6 photoconversion.