Applying both kinetic and thermodynamic measures to promote solar-driven photocatalytic ozonation on defect-engineered porous tungsten oxide

Abstract

Mass transfer of ozone within the inner structure of a catalyst and utilization efficiency of the photo-generated electrons are two decisive factors governing the production of hydroxyl radicals (•OH) in photocatalytic ozonation process from kinetic and thermodynamic perspectives, respectively. For achieving precise dual-control, defect-engineered tungsten oxide with a periodic porous architecture (p-WO3-OV) is synthesized. Compared with pristine WO3, p-WO3-OV achieves a 7.6-fold increase in the reaction rate of solar photocatalytic ozonation, accompanied by a 2.3-fold enhancement in the ozone utilization efficiency. The constructed periodic porous structure shortens the migration path of charge carriers and promotes the fluidity of the reactants. The rich oxygen vacancies in WO3 enhance the generation of charge carriers and promote O3 interactions. This work provides mechanistic insights into both the kinetic boost endowed by porous nanoarchitecture, and the thermodynamic modulation enabled by defect engineering to achieve the synergy in solar-driven photocatalytic ozonation.