LAUSR

Pickering emulsions provide an efficient platform for interfacial catalysis, but product separation and catalyst recycling rely on time- and energy-consuming centrifugation or filtration. Herein, three hexaniobate-based ionic liquids, [CnMIM]Nb6 (n = 12, 14 and 16), have been successfully synthesized by self-assembly of hexaniobate (Nb6) with long alkyl chain-modified imidazole cations (CnMIM). Interestingly, the surface wettability of [C16MIM]Nb6 can be regulated by redox reactions, and the rapid switch between emulsification and demulsification can be achieved by alternately adding oxidant (H2O2) and reductant (Na2SO3) agents. Furthermore, studies suggest that the redox-responsive behavior is related to the reversible transformation between [C16MIM]Nb6 and peroxohexaniobate [C16MIM]Nb6-O2, which leads to the rearrangement of hydrophobic long chains on imidazole cations around hydrophilic Nb6. Moreover, [C16MIM]Nb6 can effectively catalyze oxidative desulfurization (conversion > 99%), and the separation of clean model oil and the recycling of the interfacial catalyst were realized in a facile route.