Supported MOCVD TiO₂ Thin Films Grown on Modified Stainless Steel Mesh for Sensing Applications

Area of Science:

• Materials Science
• Environmental Sensing
• Nanotechnology

Background:

• Semiconductor metal oxides, particularly titanium dioxide (TiO2), are vital sensing materials.
• TiO2 thin films offer stability, non-toxicity, and photocatalytic properties for sensor applications.
• Chemical oxygen demand (COD) sensors utilize TiO2's photocatalysis to oxidize organic pollutants.

Purpose of the Study:

• To develop nanostructured TiO2 thin films on metallic mesh for enhanced COD sensing.
• To optimize inorganic acid-based etching protocols for increased surface area.
• To evaluate the photocatalytic activity of the developed TiO2 thin films as COD sensors.

Main Methods:

• Low-pressure metal organic chemical vapor deposition (MOCVD) for TiO2 film growth on AISI 316 mesh.
• Development and testing of inorganic acid-based chemical etching protocols (HCl/H2SO4 at 55 °C).
• Characterization using SEM, XRD, EDX, and XPS; photocatalytic testing with model pollutants (ISO 10678:2010).

Main Results:

• Optimized HCl/H2SO4 etching at 55 °C yielded the most suitable surface morphology for increased surface area.
• MOCVD-grown TiO2 films on etched mesh demonstrated significantly enhanced photocatalytic activity.
• The best performing sensor showed a 60% increase in activity, degrading 66 µmol of MB per square meter per hour.

Conclusions:

• Nanostructured TiO2 thin films on optimized etched metallic mesh represent a promising advancement in COD sensor technology.
• The developed fabrication method enhances surface area and photocatalytic efficiency.
• This approach offers a viable pathway for creating high-performance environmental sensors.