Experimental data reveal that the incorporation of carbonyl groups into polymer matrix can significantly enhance singlet oxygen ((1) O2 ) generation and suppress production of other reactive oxygen species. Excitonic processes investigated by phosphorescence spectroscopy reveal enhanced triplet-exciton generation in the modified g-C3 N4 , which facilitate (1) O2 generation through an energy transfer process. Benefiting from this, the modified g-C3 N4 shows excellent conversion and selectivity in organic synthesis.
Excitonic effects, arising from the Coulomb interactions between photogenerated electrons and holes, dominate the optical excitation properties of semiconductors, whereas their influences on photocatalytic processes have seldom been discussed. In view of the competitive generation of excitons and hot carriers, exciton dissociation is proposed as an alternative strategy for hot-carrier harvesting in photocatalysts. Herein, by taking heptazine-based melon as an example, we verified that enhanced hot-carrier generation could be obtained in semicrystalline polymeric photocatalysts, which is ascribed to the accelerated exciton dissociation at the abundant order-disorder interfaces. Moreover, driven by the accompanying electron injection toward ordered chains and hole blocking in disordered chains, semicrystalline heptazine-based melon showed an ∼7-fold promotion in electron concentration with respect to its pristine counterpart. Benefiting from these, the semicrystalline sample exhibited dramatic enhancements in electron-involved photocatalytic processes, such as superoxide radical production and selective alcohol oxidation. This work brightens excitonic aspects for the design of advanced photocatalysts.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.