Engineering Hierarchical Architecture of Metal‐Organic Frameworks for Highly Efficient Overall CO₂ Photoreduction

Abstract

Previous studies on syntheses of metal‐organic frameworks (MOFs) for photocatalytic CO2 reduction are mainly focused on the exquisite control over the net topology and the functionality of metal clusters/organic building blocks. This contribution demonstrates that the rational design of MOF‐based photocatalyst can be further extended to the hierarchical structure at micrometer scales well beyond the conventional MOF design at the molecular level. By taking advantage of the disparity of two selective MOFs in nucleation kinetics, a hierarchical core–shell MOF@MOF structure is successfully constructed through a simple one‐pot synthesis. Besides inheriting the high porosity, crystallinity, and robustness of parent MOFs, the obtained heterojunction exhibits extended photoresponse, optimized band alignment with large overpotential, and greatly enhanced photogenerated charge separation, which would be hardly realized by the merely molecular‐level assembly. As a result, the challenging overall CO2 photoreduction is achieved, which generates a record high HCOOH production (146.0 µmol/g/h) without using any sacrificial reagents. Moreover, the core–shell structure exhibits a more effective use of photogenerated electrons than the individual MOFs. This work shows that harnessing the hierarchical architecture of MOFs present a new and effective alternative to tuning the photocatalytic performance at a mesoscopic level.

Thermo-, Electro-, and Photocatalytic CO2 Conversion to Value-Added Products over Porous Metal/Covalent Organic Frameworks

“…With the tailored structure, precise active sites and photo absorption ability, MOFs and MOF composites emerge as promising platforms which can exhibit detailed information about the effective electron–hole separation and provide excellent performance in solar-driven CO 2 reduction . We paid particular attention to regulation of the coordination spheres in single MOF catalysts, fabrication of MOF heterojunctions, and construction of MOF films to boost electron–hole separation. ,− …”

“…Compared with a single MOF catalyst, the MOF heterojunctions can significantly enhance charge separation and photocatalytic activity because of their different energy levels and optimized energy bands. Accordingly, we fabricated a MOF heterojunction (PCN@UiO) based on PCN-222-Ni and UiO-67-NH 2 with a core–shell structure, making use of their difference in nucleation kinetics (Figure a,b) . Under solvothermal reaction settings, the homogeneous nucleation of PCN-222-Ni with a high nucleation rate first took place, and was followed by the nucleation growth of UiO-67-NH 2 around PCN-222-Ni.…”

“…For the CO 2 photocatalysis process, the electron–hole pair recombination should be suppressed to provide sufficient electrons for the reduction process. To address this problem, our group indicated how regulation of the coordination spheres, fabrication of the architecture of MOF heterojunctions, and film engineering of MOFs, focusing mainly on intensifying electron–hole separation, might boost photocatalytic CO 2 reduction. ,− …”

A critical review on emerging photocatalysts for syngas generation via CO2 reduction under aqueous media: a sustainable paradigm

“…A number of studies have manifested that CO 2 can be efficiently reduced into CH 4 and CO via MOF assisted photocatalysis. 183,184 However, in this section particularly we will discuss only photocatalytic CO production synergistically with H 2 production for syngas generation from the CO 2 -H 2 O mixture.…”

A {Zn4} cluster as a bi-functional luminescence sensor for highly sensitive detection of chloride ions and histidine in aqueous media

“…A variety of coordinated metal clusters with special structures can be obtained by designing organic ligands and changing the inorganic metal nodes, giving varied functions, 34–36 such as luminescence, magnetism, catalysis, etc. 37–58 Among them, LCMCs have been widely used in the detection of metal ions, nitro explosives and biomolecules because of their well-defined active sites, accurately tailorable structures and excellent luminescent properties, enabling mechanism-based luminescence sensing optimization. 59–65 According to literature studies, there are few reports using LCMCs as luminescence sensors for detecting halide ions or amino acids, especially no bifunctional sensors for halide ions and amino acid determination.…”