Functional nanostructured materials: Aerosol, aerogel, and de novo synthesis to emerging energy and environmental applications

Abstract In this review, we introduce advanced synthetic methods for functional nanostructured materials (in powder form) bridging to the development in emerging energy and environmental applications. Three types of synthetic methods (aerosol-based, aerogel-based, and de novo methods) are introduced, all of which have shown to be extensively investigated as novel routes to create nanostructured materials with designed material properties (i.e., controlled size, shape, porosity, and chemical composition are to be achievable). The typical experimental setup and the general experimental procedure for material preparation via the above three synthesis routes are discussed. Complementary characterization approaches are employed to study material properties of the synthesized nanostructured materials via the three synthesis routes. Here we investigate: (1) CuxO-CeO2, Ni-CeO2, and CuxO nanoparticle-encapsulating metal–organic framework (MOF) hybrid nanoparticles synthesized via the aerosol-based method; (2) Cr-encapsulating MOF (Cr-MOF-199), Au-encapsulating MOF (Au@ZIF-8), and MOF-derived nanocomposites (CuO/CuCr2O4) produced via the de novo route; (3) a variety of aerogels (carbon, metal oxide, polymer) with high porosity created by the aerogel-based approach. Finally, several examples of emerging energy and environmental applications are introduced using these functional nanostructured materials, including (1) catalytic transformation to chemicals by using precious metal nanoparticles-embedded MOFs and the MOF-derived nanocomposites as the catalysts; (2) methane combustion using CuxO-CeO2 hybrid nanoparticles as catalyst, (3) methane dry reforming with CO2 using Ni-CeO2 hybrid nanoparticles as catalyst; (4) CO2 capture by fluoroalkyl silane-modified mesoporous silica and polymethylsilsesquioxane (PMSQ) aerogel membranes; (5) adsorption of organic solvent, dye, and oil by cetyltrimethylammonium bromide-modified PMSQ aerogel.