Improving photocatalytic oxidation of semiconductor (TiO2, SnO2, ZnO)/CNTs for NOx removal

Traditional semiconductors, i.e., SnO2, ZnO, and TiO2 have a good photocatalytic activity but still many disadvantages to applying in industry. In this study, these semiconductors are combined by commercial CNTs to form heterojunctions by a ball-milling route. The physical-chemical analyses include X-ray diffraction pattern (XRD), diffused reflectance spectra (UV-Vis DRS), Fourier transform infrared spectrum (FTIR), Mott-Schottky analysis, high-resolution transmission electron microscopy (HRTEM), and selected area electron diffraction (SAED) are run to characterize the as-prepared materials. The total photocatalytic NOxefficiency of SnO2/CNTs, ZnO/CNTs, and TiO2/CNTs composites generate green products, i.e., NO3-, HNO3, etc. with 10%, 10.1%, and 41.25% after 30 min under visible light illumination, respectively. We also found that ZnO/CNTs easily inactivated the photocatalytic ability and converted NO gas to a more toxic product. Meanwhile, the highest selectivity of green products conversion belongs to SnO2/CNTs nanocomposite. Our findings will design and select an excellent photocatalytic oxidation system for NOxremoval towards a flue gas treatment established.(c) 2023 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Automated summary

In this study, traditional semiconductors are combined with carbon nanotubes to form composites with high photocatalytic oxidation performance, which shows great potential for NOx removal and flue gas treatment.