Controlled synthesis of Bi₂O₃/TiO₂ catalysts with mixed alcohols for the photocatalytic oxidation of HCHO

ABSTRACT

Bi₂O₃/TiO₂ photocatalysts were prepared by a hydrothermal method. The photocatalysts were applied to the catalytic oxidation of indoor formaldehyde vapors under irradiation by an light-emitting diode energy-saving lamp. The characterization methods including Brunauer-Emmett-Teller, X-ay diffraction, UV-vis spectra, scanning electron microscopy, Transmission electron microscopy and X-ray photoelectron spectroscopy analysis were used to investigate the crystalline structure, morphology, specific surface area and porosity. The effects of the preparation conditions, including the type of alcohols, molar ratio and calcination temperature, on the morphology, structure and crystalline phase of the catalyst were also investigated. The results reveal that the morphology could be controlled by using different types of alcohols, especially mixed alcohols. The morphology played a key role in determining the photodegradation efficiency of formaldehyde. According to the experimental results, the Bi₂O₃/TiO₂ catalysts with amorphous particles showed the highest activity. The presence of anatase TiO₂ and Bi₄(TiO₄)₃ with a heterojunction structure was the main reason for the high activity, and they were beneficial for increasing the separation of the photogenerated electrons and holes and decreasing their recombination through electron transformations.

KEYWORDS:

• Photocatalytic oxidation
• heterojunction structure
• TiO₂
• Bi₂O₃
• HCHO

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was financially supported by the Natural Science Foundation of Jiangsu Province [grant number BK20170954] and the National Natural Science Foundation of China [grant numbers 21272118, 21577065 and 21501097]. This work was also supported by A Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD), the Top-notch Academic Programs Project of Jiangsu Higher Education Institutions [grant number PPZY2015C222], the Jiangsu Joint Laboratory of Atmospheric Pollution Control, and the Jiangsu Engineering Technology Research Centre of Environmental Cleaning Materials.