Micro- and nano-structure evolution of soot from isooctane and 2,5-dimethylfuran flames in photocatalytic degradation

Abstract

Soot is a sort of critical pollutants from incomplete combustion of carbonaceous fuel. Photocatalytic decomposition of soot from the isooctane and 2,5-dimethylfuran (DMF) flames was carried out under vacuum ultraviolet irradiation. The change of PEG addition led to different morphology of titanium dioxide films as the photocatalysts, which might affect photocatalytic soot decomposition. The photodegradation process of soot was analyzed by digital cameras, the field emission scanning electron microscope (FESEM) analysis, and the higher resolution transmission electron microscope (HRTEM) analysis. The photocatalytic degradation time of soot from DMF flames is far fewer than that of soot from isooctane flames. Loose deposition of DMF soot is beneficial for the photocatalytic decomposition process due to the blocking to incident light reducing. Nanostructures of soot particles from different flames were obtained and analyzed by HRTEM. Soot samples that were collected by DMF flames exhibited higher oxidation reactivity and more surface oxygen than that from isooctane flames. The above factors which might affect the photocatalytic degradation time of soot were analyzed to compare differences.