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

Abstract

Photocatalytic conversion of CO2 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 CO2 reduction technique has shown great promise, the successful conversion of CO2 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-MoS2 (TpPa-1/Co-1T-MoS2) composite with the appropriate band edge potential and an enhanced charge separation to improve its CO2 photoreduction efficiency under visible light irradiation. With a selectivity of 93%, the developed TpPa-1/Co-1T-MoS2 nanocomposite exhibits impressive photocatalytic CO2 reduction efficiency of up to ∼196 μmol g–1 h–1 of CO. Bare TpPa-1 and Co-1T-MoS2 both had around 1.23 and 1.6 times lower CO than TpPa-1/Co-1T-MoS2. Parametric analyses show that the TpPa-1 and Co-1T-MoS2 counterparts have a remarkable cumulative influence on the specificity and efficacy of photoreduction of CO2 to CO. TpPa-1/Co-1T-MoS2 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. 13C labeling confirms that the selective conversion of CO2 to CO was facilitated by couplings between TpPa-1 and Co-1T-MoS2, 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.

Nanoarchitectonics of Hollow Covalent Organic Frameworks: Synthesis and Applications

“…Recently, Do et al presented the synthesis of a hollow nanospherical TpPa-1 through a hard template method. 98 Then, the hollow COF was decorated with single-atom Co-1T-MoS 2 . Compared with bare TpPa-1 and Co-1T-MoS 2 , the resulting composite displayed a photocatalytic CO 2 reduction efficiency of up to ∼196 μmol g −1 h −1 of CO with a high selectivity of 93% under visible light irradiation.…”

“…Nanostructuring COFs, specifically those with hollow morphologies, such as spheres, ,, bowl, and capsule, have shown great potential in improving their photocatalytic performance. Notably, compared with those of bulk COFs, these hollow COFs have demonstrated enhanced photocatalytic activities in photocatalytic hydrogen evolution, ,,,, CO 2 conversion, ,− oxidation, and degradation of environmental contaminants. ,,,, …”

“…Because of the coexistence of Lewis acid sites from the Fe clusters in NH 2 –MIL-101­(Fe) and Brønsted base sites from the aminal groups in SNW-1, the resulting MOF/COF composite exhibited high activity in the photodegradation of various pollutants and photocatalytic hydrogen evolution. Recently, Do et al presented the synthesis of a hollow nanospherical TpPa-1 through a hard template method . Then, the hollow COF was decorated with single-atom Co-1T-MoS 2 .…”

Emerging Single-Atom Catalysts and Nanomaterials for Photoelectrochemical Reduction of Carbon Dioxide to Value-Added Products: A Review of the Current State-of-the-Art and Future Perspectives

“…61 Employing double perovskite nanomaterial (NMT) such as Cs 2 AgBiBr 6 encapsulated with TiO 2 to fabricate the TiO 2 /Cs 2 AgBiBr 6 hybrid composite revealed excellent PC activity resulting in the formation of CO and CH 4 amounting to 5.72 μmol g −1 h −1 and 8.46 μmol g −1 h −1 , respectively. 30 A hybrid composite consisting of keto-enamine covalent organic framework TpPa-1 combined with cobalt single atom Co-1T-MoS 2 to form a photocatalytic composite of TpPa-1/Co-1T-MoS 2 resulted in the formation of 196 μmol g −1 h −1 of CO. 62 In contrast to the PC technique, the PEC process involves the combined characteristics of the EC and PC techniques. Although several PEC reactor configurations have been employed, they can be classified broadly into two types.…”

MoS2-Based Nanocomposites for Photocatalytic Hydrogen Evolution and Carbon Dioxide Reduction

“…Primarily, such a journey started with the invention of graphene in 2004 by Andre Geim and Kostya Novoselov. , Their outstanding properties significantly influence energy-related fields, such as solar cells, photo and electrocatalysis, light-emitting diodes (LEDs), transistors, and photodetectors. − Like graphene, layered transition metal dichalcogenides (TMDCs) were introduced as another class of 2D materials with intriguing properties that could potentially replace noble metals in catalytic applications. Molybdenum disulfide (MoS 2 ) mainly shows wide applications in various energy-related fields. − Most importantly, MoS 2 -based nanocomposites have developed significantly in photocatalysis, such as pollutant degradation, , H 2 production, , and CO 2 reduction. , Therefore, we explore the advancement of nanocomposites based on MoS 2 in photocatalytic H 2 evolution and CO 2 reduction.…”