This study deals with aerosol synthesis of carbon nano onions (CNOs) containing TiO₂ with oxygen vacancies and investigation of their morphological and optical and photocatalytic features. The CNO composites were synthesized employing closed flame spray process and as obtained material was investigated using TEM, Raman spectroscopy, FTIR, Thermal optical carbon analyser, TGA and UV Vis absorption analysis. Results show that that CNOs exhibit concentric graphitic layered structures containing mixed phases TiO₂ with oxygen vacancies. Incorporation of TiO₂ leads to defects induced structure in CNOs and results in extended absorption in visible region, rendering promising material for photocatalytic and photochemical applications.

Flame spray pyrolysis (FSP) systems are getting an increasing level of attention because of their capacity to produce nanoparticles with well-defined characteristics for the production of innovative materials. To achieve good control of nanoparticles characteristics, a deep understanding of the processes governing their production in the flame is required. To this end, we have developed an experimental setup enabling us to study of TiO₂ synthesis in a laminar H₂/TTIP/air diffusion co-flow pre-vaporized flame. In this contribution, we will illustrate how to combine in-situ optical diagnostic, ex-situ measurements and detailed computational fluid dynamics to obtain new fundamental insights on flame synthesis.

Molecular dynamics (MD) simulations of air molecules accounting for their shape and force fields revealed recently that inelastic collisions are abundant. Here, fully atomistic MD simulations are conducted to assess the diffusivity of silica nanoparticles (NPs) in air. As NP size approaches that of air, NP diffusivity is increasingly affected by inelastic collisions, resulting in various collision patterns like grazing, head-on, and orbiting. The MD-derived diffusivities for sub-5 nm NPs were 50-60% smaller than those predicted by the Stokes-Cunningham-Millikan (SCM) equation. Additional simulations treating NPs and air as hard spheres yielded diffusivities that matched with the SCM equation.

We design a novel monolithic wall-flow reactor with optimized structure that can accommodate an unprecedented O(10) higher amount of catalytic particles (loaded via an aerosol process) vs washcoated technology and exhibit much lower overall flow resistance than a similar packed bed reactor. Prototype reactors loaded with catalytic powders are evaluated with respect to their flow resistance confirming their high potential. Employing rational approximations we obtain an analytical solution for the flow through the monolithic reactor and the dependance of the pressure drop on the parameters of the problem, which is shown to be in excellent agreement with the data.