The Composite TiO₂-CuO_x Layers Formed by Electrophoretic Method for CO₂ Gas Photoreduction

Area of Science:

• Materials Science
• Nanotechnology
• Photocatalysis

Background:

• Titanium dioxide (TiO2) is a widely studied photocatalyst.
• Enhancing TiO2 photocatalytic activity and expanding its spectral response are key research goals.
• Composite materials offer a route to tune semiconductor properties.

Purpose of the Study:

• To control the properties of TiO2-CuOx composite layers for photocatalytic applications.
• To investigate the effect of varying CuOx content on material characteristics and performance.
• To demonstrate a simple method for fabricating tailored photocatalytic materials.

Main Methods:

• Electrophoretic deposition from an isopropanol-based suspension.
• Use of sodium lauryl sulfate surfactant to control layer uniformity and morphology.
• Characterization of optical band gap using UV-VIS-NIR diffuse reflectance spectra.
• Analysis of charge carrier ratios via open-circuit potential measurements.

Main Results:

• Uniform TiO2-CuOx composite layers with controlled CuO_x content (1.5, 5.5, 11 wt.%) were successfully fabricated.
• Addition of CuO_x broadened the photosensitivity range of TiO2 by introducing a second absorption edge.
• The ratio of free charge carriers (n and p) could be tuned by adjusting the CuO_x content.
• Photocatalytic activity for CO2 photoreduction to methanol increased with higher CuO_x loading.

Conclusions:

• Electrophoretic deposition is an effective method for producing TiO2-CuOx composite layers with tunable properties.
• The composite material exhibits enhanced photocatalytic performance compared to pure TiO2.
• Controlled CuOx content allows for optimization of charge carrier dynamics and catalytic efficiency.