Coverage Layer Phase Composition-Dependent Photoactivity of One-Dimensional TiO₂-Bi₂O₃ Composites

Area of Science:

• Materials Science
• Nanotechnology
• Photocatalysis

Background:

• Developing efficient photocatalysts is crucial for environmental remediation.
• Titanium dioxide (TiO2) is a widely studied photocatalyst, but its efficiency can be limited.
• Bismuth oxide (Bi2O3) has shown promise in enhancing photocatalytic performance.

Purpose of the Study:

• To synthesize TiO2-Bi2O3 composite rods with controlled Bi2O3 phases.
• To investigate the structural and morphological properties of the composite materials.
• To evaluate the photocatalytic activity of the synthesized TiO2-Bi2O3 composites for methyl orange degradation.

Main Methods:

• Hydrothermal growth of rutile TiO2 nanorod templates.
• Sputtering deposition of Bi2O3 thin films onto TiO2 templates.
• In situ radio-frequency magnetron sputtering and post-annealing for different Bi2O3 phases (beta-Bi2O3 and alpha/beta-Bi2O3 dual-phase).
• Characterization using X-ray diffraction (XRD) and scanning electron microscopy (SEM).
• Photocatalytic activity testing via methyl orange decomposition.

Main Results:

• Successfully synthesized TiO2-Bi2O3 composite rods with beta-Bi2O3 and alpha/beta-Bi2O3 phases.
• Morphological analysis revealed flat beta-Bi2O3 layers and sheet-like alpha/beta-Bi2O3 structures on TiO2 rods.
• The TiO2-alpha/beta-Bi2O3 composite with a sheet-like structure exhibited significantly enhanced photocatalytic activity.
• Improved photoinduced charge separation efficiency was observed in the TiO2-alpha/beta-Bi2O3 composites.

Conclusions:

• The synthesis method allows for controlled decoration of TiO2 nanorods with different Bi2O3 phases.
• The sheet-like alpha/beta-Bi2O3 morphology on TiO2 nanorods is key to enhanced photocatalytic performance.
• TiO2-alpha/beta-Bi2O3 composite rods show great potential as efficient photocatalysts and photoelectrodes.