Hierarchical hollow WO3 microspheres with tailored surface oxygen vacancies for boosting photocatalytic selective conversion of biomass-derived alcohols

Abstract

Selective conversion of biomass-derived alcohols into carbonyl compounds via visible-light photocatalysis is realized over hierarchical hollow WO3 microspheres with tailored surface oxygen vacancies, which presents the remarkably boosted photoactivity in terms of selectivity and activity, intrinsically attributing to the strong synergetic effect of hierarchical spherical cavity and surface oxygen vacancies simultaneously. The hierarchical spherical cavity, substantially constructed by the self-interconnected nanosheets, enhances the light-harvesting ability via multiple light reflections not only in spherical cavity but also among the self-interconnected nanosheets. Surface oxygen vacancies favor the energy band gap narrowing via forming a miniband just below the conduction band and then extend the photoresponse region, further boosting the light-harvesting ability. Importantly, surface oxygen vacancies function as the electron sinks to capture photoelectrons and thus restrict their recombination probability with holes, finally improving the photoelectron-hole separation efficiency. Meanwhile, this photocatalyst presents excellent reusability, showing its promising potential in practical applications. This work sheds light on a new application of hierarchical WO3 microspheres with tailored surface oxygen vacancies and its strong synergetic effect of hierarchical structures and surface oxygen vacancies on photocatalytic performance, delivering new insights for rationally designing highly active photocatalysts applied in future green and sustainable organic transformation reactions.