Confining and Highly Dispersing Single Polyoxometalate Clusters in Covalent Organic Frameworks by Covalent Linkages for CO₂ Photoreduction

Abstract

Single clusters have attracted extensive research interest in the field of catalysis. However, achieving a highly uniform dispersion of a singlecluster catalyst is challenging. In this work, for the first time, we present a versatile strategy for uniformly dispersed polyoxometalates (POMs) in covalent organic frameworks (COFs) through confining POM cluster into the regular nanopores of COF by a covalent linkage. These COF-POM composites combine the properties of light absorption, electron transfer, and suitable catalytic active sites; as a result, they exhibit outstanding catalytic activity in artificial photosynthesis: that is, CO 2 photoreduction with H 2 O as the electron donor. Among them, TCOF-MnMo 6 achieved the highest CO yield (37.25 μmol g −1 h −1 with ca. 100% selectivity) in a gas−solid reaction system. Furthermore, a mechanism study based on density functional theory (DFT) calculations demonstrated that the photoinduced electron transfer (PET) process occurs from the COF to the POM, and then CO 2 reduction and H 2 O oxidation occur on the POM and COF, respectively. This work developed a method for a uniform dispersion of POM single clusters into a COF, which also shows the potential of using COF-POM functional materials in the field of photocatalysis.

Ni–Co Bimetallic Hydroxide Nanosheet Arrays Anchored on Graphene for Adsorption‐Induced Enhanced Photocatalytic CO2 Reduction

“…Moreover, Figure S4, Supporting Information, showed the morphology of the catalyst before and after the reaction did not change significantly. The above results indicate that the Ni x Co y –GR composite with a hierarchical nanosheet‐array structure has excellent catalytic durability and stability, [ 33 ] and it can be used as a potential photocatalyst with practical application value for the highly selective conversion of CO 2 into CO.…”

Covalent Organic Framework Based Functional Materials: Important Catalysts for Efficient CO2Utilization

“…Polyoxometalates (POMs), a class of special metal nanoclusters, have also received much attention in terms of the photocatalytic CO 2 RR. Recently, the Lan group proposed a general strategy for uniformly dispersing POMs in COFs by confining the POMs in the regular pores of the COFs through covalent bonds [26a] . The obtained COF‐POMs nanocomposites combined the merits of strong light absorption, fast electron transfer, and appropriate catalytic sites.…”

Polyoxometalate‐Based Metal Organic Frameworks: Recent Advances and Challenges

“…Therefore, finding a stable and size‐matched carrier is the key to solving the above problems. As a result, a large number of studies have emerged to load POMs onto different carriers to form various types of loaded catalysts, [6] such as POM@COF, [7] which is formed by combining with organic type carrier covalent organic framework, and POM@MOF, [8] which is combined with inorganic type carrier metal organic framework.…”