Molecular Compartments Created in Metal–Organic Frameworks for Efficient Visible-Light-Driven CO₂ Overall Conversion

Abstract

We report the construction of molecular compartments by the growth of narrow-band semiconductor nanoparticles, tungsten oxide and its hydrate, in the mesopores of a metal–organic framework (MOF), MIL-100-Fe. The location of these nanoparticles in pores and their spatial arrangement across the MOF crystal are unveiled by powder X-ray diffraction and small-angle neutron scattering, respectively. Such a composition with pore-level precision leads to efficient overall conversion of gas-phase CO2 and H2O to CO, CH4, and H2O2 under visible light. When WO3·H2O nanoparticles are positioned in 2.5 nm mesopores with 24 wt %, the resulting composite, namely, 24%-WO3·H2O-in-MIL-100-Fe, exhibits a CO2 reduction rate of 0.49 mmol·g–1·h–1 beyond 420 nm and an apparent quantum efficiency of 1.5% at 420 nm. These performances stand as new benchmarks for visible-light-driven CO2 overall conversion. In addition to the size and location of semiconductor nanoparticles, the coordinated water species in the crystal are found critical for high catalytic activity, an aspect usually overlooked.

Integrating Sub‐Nano Catalysts into Metal‐Organic Framework toward Pore‐Confined Polysulfides Conversion in Lithium‐Sulfur Batteries

“…Thus the increment of the intensity of 111 reflections of MOF-TOC suggests the accommodation of TOCs in MOF pores. [39,40] The valence and chemical composition of MOF-TOC were first analyzed by X-ray photoelectron spectroscopy (XPS) tests. In the Ti 2p spectrum (Figure S4, Supporting Information), Ti 2p 3/2 and Ti 2p 1/2 corresponding to the Ti 4+ -O bond appear at 458.8 and 464.6 eV, respectively.…”

Precise Regulation of the Coordination Environment of Single Co(II) Sites in a Metal–Organic Framework for Boosting CO2 Photoreduction

“…Metal–organic frameworks (MOFs), a class of crystalline porous materials assembled by metal ions/clusters with organic ligands, − possess well-defined and tailorable structures, which provide an ideal platform for structural design and accurate modification on the atomic level, bridging the heterogeneous and homogeneous catalysts. − In recent years, MOFs have been recognized to be very promising in CO 2 photoreduction. − Typically, different functional groups with chelating ability can be handily grafted onto MOF pore walls via mixed-ligand or post-synthetic modulation (PSM) strategies. − These chelating sites can immobilize different metal centers and allow further modification. − With the above thoughts in mind, MOFs might be the perfect candidates to precisely regulate the coordination environment around the catalytic metal sites for excellent performance in photocatalytic CO 2 reduction.…”

Hollow Mesoporous Metal Organic Framework Single Crystals Enabled by Growth Kinetics Control for Enhanced Photocatalysis

“…[1][2][3][4] Benefit from the complex topological structure, high specific surface area, adjustable pore size, and morphology, they hold great promise in a variety of potential applications including gas adsorption and separation, drug delivery, catalysis, and so on. [5][6][7][8] However, the inherent micropores bring about the hindrance to mass transfer and limit the accessibility of macromolecules, resulting in poor performance. In this regard, mesoporous engineering provides one promising way to address the above issues, and thus mesoporous MOFs with various microstructures have been designed.…”