Boron nitride quantum dots modified carbon-defects ultra-thin porous carbon nitride: double channels and quantum size effects facilitate photogenerated carrier migration and exciton dissociation

Abstract

Graphite carbon nitride possesses great promise for visible photocatalysis, but the bulk carbon nitride prepared from nitrogen-rich precursors such as melamine has inherent drawbacks such as retarded photogenerated carrier migration and exciton effects, which limit its application. Herein, we constructed a novel Boron nitride quantum dots modified carbon-defects ultra-thin porous carbon nitride (BNQDs/Vc-UPCN). The double channels were constructed by carbon-defects structure and Boron nitride quantum effect to overcome its inherent drawbacks and applied to the photodegradation of common persistent organic pollutants (methylene blue). The structure, porosity, elemental composition, optical properties, photoelectrochemical properties, and photocatalytic properties of the prepared BNQDs/Vc-UPCN composites were investigated using various characterization methods. Meanwhile, the results of radical trapping experiments and electron spin resonance characterization demonstrated that BNQDs/Vc-UPCN promote molecular oxygen activation more than Vc-UPCN did. In terms of degradation effect, the best sample (BC-1) is 10 times more effective than the initial sample (BCN). This study proposes an effective mechanism for constructing novel visible-light-driven photocatalysts using carbon-defects ultra-thin structures and quantum dots, which can be used for the treatment of organic pollutants.