Bromo- and iodo-bridged building units in metal-organic frameworks for enhanced carrier transport and CO2 photoreduction by water vapor

Abstract

Organolead halide hybrids have many promising attributes for photocatalysis, e.g. tunable bandgaps and excellent carrier transport, but their instability constraints render them vulnerable to polar molecules and limit their photocatalysis in moisture. Herein, we report the construction of metal–organic frameworks based on [Pb2X]3+ (X = Br–/I–) chains as secondary building units and 2-amino-terephthalate as organic linkers, and extend their applications in photocatalytic CO2 reduction with water vapor as the reductant. Hall effect measurement and ultrafast transient absorption spectroscopy demonstrate the bromo/iodo-bridged frameworks have substantially enhanced photocarrier transport, which results in photocatalytic performances superior to conventional metal-oxo metal-organic frameworks. Moreover, in contrast to lead perovskites, the [Pb2X]3+-based frameworks have accessible porosity and high moisture stability for gas-phase photocatalytic reaction between CO2 and H2O. This work significantly advances the excellent carrier transport of lead perovskites into the field of metal-organic frameworks.

Organolead Halide-Based Coordination Polymers: Intrinsic Stability and Photophysical Applications

“…The vast majority of conventional organolead halide structures occupy corner- or edge-sharing PbX 6 octahedra, rendering negatively charged Pb-X-Pb connectivity that is charge-balanced by extraframework organoammonium cations. , However, in our organolead halide coordination polymers, the coordination sphere of the Pb 2+ centers include both halide species and the carboxylate oxygens of the organic linkers, therefore often presenting irregular seven- , or eight-coordinate ,,, geometry. Meanwhile, the deprotonation of structure-directing organic moieties affords the cationic haloplumbate-based building units, which are the excellent additions to the traditional anionic lead halide sublattices of organolead halide perovskites.…”

“…Commun. 2022, 13, 4592 2. This study reports a porous lead halide MOF-type architecture for gas-phase photocatalytic reaction between CO 2 and water vapor, showing higher carrier transport characteristics over conventional metal-oxo MOFs.• Peng, C.; Song, X.; Yin, J.; Zhang, G.; Fei, H.…”

Polarization engineering of porous organic polymers for superior photocatalytic synthesis of disulfides and CO2reduction

“…7a and S18 and S19,† CO 2 at the OBCP interface is initially activated to generate adsorbed *CO 2 , which is subsequently converted into *COOH and *CO by the energy upslope. 51 Afterwards, the transition from *CO to *CHO is thermodynamically favorable, absorbing an energy of 5.56 eV, whereas the desorption of CO requires an energy of 5.6 eV. Therefore, *CO can be further converted into *CHO.…”

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

“…H 2 O 2 was generated as the product in the oxidation reaction consuming holes left from CO 2 reduction. Although the observation of H 2 O 2 was rare in photocatalytic overall CO 2 conversion, − keeping the oxidation product out from the gas phase favored the separation and collection of gaseous reduction products, CO and CH 4 . It is worth noting that the ratio of the total consumed holes to electrons is nearly stoichiometric in the overall redox reaction, demonstrating excellent charge separation.…”