Degradation of formaldehyde aqueous solution by Bi based catalyst and its activity evaluation

Area of Science:

• Materials Science
• Environmental Chemistry
• Catalysis

Background:

• Bismuth-based catalysts are recognized for their photochemical properties and use in environmental remediation.
• Photocatalytic degradation is a key technology for treating pollutants like formaldehyde.

Purpose of the Study:

• To synthesize and evaluate bismuth-based catalysts for formaldehyde degradation.
• To investigate the photocatalytic performance of BiVO4 and Bi2WO6 under different light sources.
• To elucidate the electronic structure contributing to catalyst activity using DFT.

Main Methods:

• Synthesis via calcination and hydrothermal methods.
• Photocatalytic degradation experiments using mercury and xenon lamps.
• Characterization using Photoluminescence (PL), UV-Vis spectroscopy, and Electrochemical Impedance Spectroscopy (EIS).
• Density Functional Theory (DFT) calculations for electronic structure analysis.

Main Results:

• BiVO4 and Bi2WO6 exhibited excellent photocatalytic activity for formaldehyde degradation under UV and visible light.
• PL, UV-Vis, and EIS tests confirmed the high activity of the synthesized catalysts.
• DFT calculations showed that the d orbitals of V and W significantly influence the energy band structure and electrochemical properties.

Conclusions:

• BiVO4 and Bi2WO6 are effective bismuth-based photocatalysts for formaldehyde removal.
• The electronic structure, particularly the influence of V and W d orbitals, is crucial for their high photocatalytic and electrochemical performance.