Cobalt-Doped MoS₂-Integrated Hollow Structured Covalent Organic Framework Nanospheres for the Effective Photoreduction of CO₂ under Visible Light

Photocatalytic conversion of CO 2 into beneficial raw chemicals has gained a great deal of attention for well over the recent decade due to its prospect for alleviating energy scarcity and global warming. Even though photocatalytic CO 2 reduction technique has shown great promise, the successful conversion of CO 2 to the intended outputs has remained a key barrier. Here, we present the design synthesis of a hollow nanospherical keto-enamine TpPa-1 covalent organic framework (COF) integrated single-atom Co-1T-MoS 2 (TpPa-1/Co-1T-MoS 2 ) composite with the appropriate band edge potential and an enhanced charge separation to improve its CO 2 photoreduction efficiency under visible light irradiation. With a selectivity of 93%, the developed TpPa-1/Co-1T-MoS 2 nanocomposite exhibits impressive photocatalytic CO 2 reduction efficiency of up to ∼196 μmol g –1 h –1 of CO. Bare TpPa-1 and Co-1T-MoS 2 both had around 1.23 and 1.6 times lower CO than TpPa-1/Co-1T-MoS 2 . Parametric analyses show that the TpPa-1 and Co-1T-MoS 2 counterparts have a remarkable cumulative influence on the specificity and efficacy of photoreduction of CO 2 to CO. TpPa-1/Co-1T-MoS 2 composite is one of the handful of notable values cited in the literature, with an apparent quantum yield of 0.7% at 420 nm under ideal conditions. 13 C labeling confirms that the selective conversion of CO 2 to CO was facilitated by couplings between TpPa-1 and Co-1T-MoS 2, which enhanced charge separation and migration to the surface. The findings show that COFs and their single-atom-based composites can be developed for next-generation photocatalytic systems and that this technology may also be interesting for other energy conversion applications.