Hydrogenated Amorphous TiO_2-x and Its High Visible Light Photoactivity.

Area of Science:

• Materials Science
• Photocatalysis
• Environmental Chemistry

Background:

• Hydrogenated crystalline titanium dioxide (TiO2) with oxygen vacancies (OV) is well-studied.
• Hydrogenated amorphous TiO2-x for photocatalysis remains underexplored.

Purpose of the Study:

• To prepare hydrogenated amorphous TiO2-x (HA-TiO2-x) via liquid plasma hydrogenation.
• To investigate the relationship between OV concentration, electronic structure, and photocatalytic performance.
• To evaluate the visible-light photoactivity and wastewater purification capabilities of HA-TiO2-x.

Main Methods:

• Liquid plasma hydrogenation strategy for HA-TiO2-x synthesis.
• Density functional theory (DFT) calculations.
• Photocatalytic degradation experiments (rhodamine B, methylene blue, theophylline).
• Total organic carbon (TOC) analysis.

Main Results:

• HA-TiO2-x demonstrated high visible-light photoactivity.
• Narrower bandgap correlated with higher photocatalytic efficiency.
• Excellent degradation of rhodamine B (98.7%), methylene blue (99.85%), and theophylline (99.87%) within 2 hours.
• Significant TOC removal rates (55%-61.8%) indicating effective wastewater purification.
• Long-term stability of the photocatalyst.

Conclusions:

• Liquid plasma hydrogenation is an effective method for producing reduced amorphous TiO2-x.
• HA-TiO2-x shows great potential for environmental remediation applications.
• The study provides fundamental insights into OV engineering for enhanced photocatalysis.