Cobalt quantum dots as electron collectors in ultra-narrow bandgap dioxin linked covalent organic frameworks for boosting photocatalytic solar-to-fuel conversion

Abstract

Photocatalysis offers a sustainable paradigm for solar-to-fuel conversion because it conflates the merits of renewable solar energy and reusable catalysts. However, the seek for robust photocatalysts that can utilize the full visible light spectrum remains challenging. Herein, cobalt quantum dots (Co QDs) were integrated into ultra-narrow bandgap dioxin linked covalent organic frameworks (COF-318) for photocatalytic solar-to-fuel conversion under full spectrum of visible light irradiation. The optimal Co10-COF exhibited superior photocatalytic CO2 reduction performance, affording a CO yield of 4232 µmol∙g−1∙h−1 and H2 evolution of 6611 µmol∙g−1∙h−1. Specifically, Co QDs played a crucial role in boosting the photocatalytic performance, which acted as electron collectors to capture the photoinduced electrons and then conveyed them to CO2 molecules. Moreover, the Co QDs modification significantly improved the CO2 adsorption and activation capacity, as well as prolonging the lifetime of photogenerated carriers. This work reveals an operable pathway for fabricating promising photocatalyst for visible-light-driven solar-to-fuel generation and provides insight into the impact of the integration of Co QDs on COF-based photocatalysts.