title: Rapid Formation of Metal-Organic Frameworks (MOFs) Based Nanocomposites in Microdroplets and Their Applications for CO2Photoreduction.
abstract: A copper-based metal-organic framework (MOF), [Cu3(TMA)2(H2O)3]n(also known as HKUST-1, where TMA stands for trimesic acid), and its TiO2nanocomposites were directly synthesized in micrometer-sized droplets via a rapid aerosol route for the first time. The effects of synthesis temperature and precursor component ratio on the physicochemical properties of the materials were systematically investigated. Theoretical calculations on the mass and heat transfer within the microdroplets revealed that the fast solvent evaporation and high heat transfer rates are the major driving forces. The fast droplet shrinkage because of evaporation induces the drastic increase in the supersaturation ratio of the precursor, and subsequently promotes the rapid nucleation and crystal growth of the materials. The HKUST-1-based nanomaterials synthesized via the aerosol route demonstrated good crystallinity, large surface area, and great photostability, comparable with those fabricated by wet-chemistry methods. With TiO2embedded in the HKUST-1 matrix, the surface area of the composite is largely maintained, which enables significant improvement in the CO2photoreduction efficiency, as compared with pristine TiO2. In situ diffuse reflectance infrared Fourier transform spectroscopy analysis suggests that the performance enhancement was due to the stable and high-capacity reactant adsorption by HKUST-1. The current work shows great promise in the aerosol route's capability to address the mass and heat transfer issues of MOFs formation at the microscale level, and ability to synthesize a series of MOFs-based nanomaterials in a rapid and scalable manner for energy and environmental applications.
authors.affiliation: Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University , Richmond, Virginia 23219, United States.
authors.forename: Xiang
authors.initials: X
authors.lastname: He
authors.affiliation: Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University , Richmond, Virginia 23219, United States.
authors.forename: Zhuoran
authors.initials: Z
authors.lastname: Gan
authors.affiliation: A.V. Luikov Heat & Mass Transfer Institute, National Academy of Sciences of Belarus , Minsk, 220072, Belarus.
authors.forename: Sergey
authors.initials: S
authors.lastname: Fisenko
authors.affiliation: Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University , Richmond, Virginia 23219, United States.
authors.forename: Dawei
authors.initials: D
authors.lastname: Wang
authors.affiliation: Department of Chemistry, Virginia Commonwealth University , Richmond, Virginia 23284, United States.
authors.forename: Hani M
authors.initials: HM
authors.lastname: El-Kaderi
authors.affiliation: Department of Mechanical and Nuclear Engineering, Virginia Commonwealth University , Richmond, Virginia 23219, United States.
authors.forename: Wei-Ning
authors.identifier: http://orcid.org/0000-0002-1935-6301
authors.initials: WN
authors.lastname: Wang
keywords: DRIFTS; HKUST-1; heat and mass transfer; photocatalysts; solvent evaporation; spray pyrolysis