Materials Today Energy
Volume 30, December 2022, 101178
Journal home page for Materials Today Energy

Metal-organic aerogels based on titanium(IV) for visible-light conducted CO2 photoreduction to alcohols

https://doi.org/10.1016/j.mtener.2022.101178Get rights and content
Under a Creative Commons license
open access

Highlights

  • Novel metal-organic aerogels based on titanium(IV) are presented.

  • These materials photocatalyze CO2 conversion under visible-light illumination.

  • The methanol production rates surpass up-to-date reported photocatalysts.

Abstract

Metal-organic frameworks (MOFs) imply an appealing source of photocatalysts as they combine porosity with tailorable electronic properties and surface chemistry. Herein, we report a series of unprecedented metal-organic aerogels (MOAs) comprised by Ti(IV) oxo-clusters and aromatic dicarboxylic linkers as an alternative to microporous MIL-125 and MIL-125-NH2 MOFs. Discrete titanium oxo-clusters polymerized upon the addition of the dicarboxylic linkers to give rise to a metal-organic gel. Their supercritical drying led to aerogels comprised by nanoscopic particles (ca. 5–10 nm) cross-linked into a meso/macroporous microstructure with surface area ranging from 453 to 617 m2·g−1, which are comparatively lower than the surface area of the microporous counterparts (1336 and 1145 m2·g−1, respectively). However, the meso/macroporous microstructure of MOAs can provide a more fluent diffusion of reagents and products than the intrinsic porosity of MOFs, whose narrower channels are expected to imply a more sluggish mass transport. In fact, the assessment of the continuous visible-light-driven photocatalytic CO2 reduction into methanol shows that MOAs (221–786 μmol·g−1·h−1) far exceed not only the performance of their microporous counterparts (49–65 μmol·g−1·h−1) but also surpass the production rates provided by up-to-date reported photocatalysts.

Keywords

Metal-organic framework
Aerogel
CO2 conversion
Photocatalysis
Goup 4 metal

Data availability

Data will be made available on request.

Cited by (0)