Designing covalent organic frameworks with Co-O4 atomic sites for efficient CO2 photoreduction

Abstract

Cobalt coordinated covalent organic frameworks have attracted increasing interest in the field of CO2 photoreduction to CO, owing to their high electron affinity and predesigned structures. However, achieving high conversion efficiency is challenging since most Co related coordination environments facilitate fast recombination of photogenerated electron-hole pairs. Here, we design two kinds of Co-COF catalysts with oxygen coordinated Co atoms and find that after tuning of coordination environment, the reported Co framework catalyst with Co-O4 sites exhibits a high CO production rate of 18000 µmol g−1 h−1 with selectivity as high as 95.7% under visible light irradiation. From in/ex-situ spectral characterizations and theoretical calculations, it is revealed that the predesigned Co-O4 sites significantly facilitate the carrier migration in framework matrixes and inhibit the recombination of photogenerated electron-hole pairs in the photocatalytic process. This work opens a way for the design of high-performance catalysts for CO2 photoreduction.

An Overview of Metal Density Effects in Single-Atom Catalysts for Thermal Catalysis

“…Considerable interest has been generated in the conversion of carbon dioxide (CO 2 ) into fuels and industrial feedstocks, as it is regarded as a promising strategy for converting greenhouse gases into usable energy, such as CO, CH 4 , methanol, C 2+ products, and so on. ,,,− Zeng et al synthesized neighboring Pt monomers by increasing the Pt loading to 7.5% while still maintaining the atomic dispersion of Pt (Figure a). At low Pt loadings, the distances between the two nearest Pt atoms in 0.2% Pt/MoS 2 were more than 3 nm, in which case the Pt atoms were characterized as isolated Pt monomers (Figure b).…”

Construction and characterization of a magnetic nanoparticle-supported Cu complex: a stable and active nanocatalyst for synthesis of heteroaryl-aryl and di-heteroaryl sulfides

“…15 Stabilization of the desired catalyst on a solid substrate was considered as an ideal solution to prepare efficient and green catalysts. [16][17][18][19] In the new century, all eyes turned towards nanotechnology in catalyst science because nanoparticles have valuable properties. [20][21][22] In the last decade, the immobilization of transition metals on nanoparticles to prepare an environmentally friendly, separable and efficient catalyst has been used as a popular catalytic system.…”

Metallosalen covalent organic frameworks for heterogeneous catalysis

“…[15] To date, a minimum of 10 different types of M-COFs have been reported. [18][19][20][21][22][23][24][25][26] These include the well-known metallolinkers such as porphyrins, [18] phthalocyanines, [19] 4, 4ʹ-bipyridine, [20] and catechols. [25] However, the mentioned metallolinkers usually assemble into M-COFs with a single metal center with uniform coordination environment.…”

“…[18][19][20][21][22][23][24][25][26] These include the well-known metallolinkers such as porphyrins, [18] phthalocyanines, [19] 4, 4ʹ-bipyridine, [20] and catechols. [25] However, the mentioned metallolinkers usually assemble into M-COFs with a single metal center with uniform coordination environment. In contrast, M(salen)-COFs exhibit a wide range of central metal elements (74 different metal elements can be utilized to create M(salen) complexes so far), diverse coordination environments, and varying numbers of active metal centers, including single atom site, dual-atom site, and even trinuclear metal sites.…”