Visual light-driven valorization of biomass-based 5-hydroxymethylfurfural over ZnS/ZnIn2S4 heterostructures as hollow nanoreactors

Hollow heterostructured nanoreactors have been used as one of the top choices for photocatalytic valorization conversion of biomass platform molecules due to their superior light-absorbing ability, high efficiency of photogenerated carrier separation and migration, ability to add a large number of reaction sites to the reaction, and good stability. In this paper, an ortho-dodecahedral hollow core-shell ZnS/ZnIn2S4 heterostructured catalyst was developed for value-added biomass conversion. The catalyst photocatalytically oxidized 5-hydroxymethylfurfural to 2,5-dicarbonylfuran in 70.9% yield under mild oxygen and visible light conditions without the addition of other auxiliary substances. Based on the characterization results and theoretical derivations, S- scheme heterojunctions with high photogenerated carrier separation-migration efficiencies are proposed. The main reactive radicals for the photocatalytic conversion of 5-hydroxymethylfurfural to 2,5-dicarbonylfuran were identified as hole radicals and superoxide radicals by electron paramagnetic resonance spectroscopy and trap experiments, and the catalysts had a good universality of oxidising biomass.