Surface Morphology-Dependent Functionality of Titanium Dioxide-Nickel Oxide Nanocomposite Semiconductors

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Heterostructures offer tunable properties for various applications.
• Controlling nanostructure morphology is crucial for optimizing material performance.
• Titanium dioxide (TiO₂) and nickel oxide (NiO) are widely studied semiconductors.

Purpose of the Study:

• To synthesize TiO₂-NiO heterostructures with controlled surface morphologies.
• To investigate the influence of annealing temperature on TiO₂-NiO nanostructure formation.
• To evaluate the photodegradation and gas-sensing properties of the synthesized materials.

Main Methods:

• Hydrothermal synthesis combined with chemical bath deposition.
• Post-annealing treatment at varying temperatures (350 °C and 500 °C).
• Characterization of structural features and evaluation of methylene blue photodegradation and acetone gas sensing.

Main Results:

• Two distinct TiO₂-NiO heterostructures were formed: NiO-nanosheet-decorated TiO₂ (NST) and NiO-nanoparticle-decorated TiO₂ (NPT).
• NPT demonstrated higher methylene blue photodegradation efficiency due to enhanced adsorption and light-harvesting.
• NST exhibited superior acetone gas-sensing response attributed to increased oxygen-deficient regions and surface-chemisorbed oxygen.

Conclusions:

• Annealing temperature significantly impacts the morphology of TiO₂-NiO heterostructures, leading to different functional properties.
• NPT are effective for dye degradation, while NST show promise for gas sensing applications.
• Tailoring nanostructure morphology is key to optimizing semiconductor heterostructures for specific environmental applications.