Chemically binding carboxylic acids onto TiO2 nanoparticles with adjustable coverage by solvothermal strategy

Area of Science:

• Materials Science
• Nanotechnology
• Surface Chemistry

Background:

• Titanium dioxide (TiO2) nanoparticles are crucial in various applications.
• Chemical modification enhances TiO2 properties.
• Conventional modification methods have limitations in efficiency.

Purpose of the Study:

• To develop an efficient solvothermal strategy for chemical modification of TiO2 nanoparticles with carboxylic acids.
• To investigate the binding mechanism and surface coverage of modifier molecules.
• To evaluate the impact of modification on TiO2 nanoparticle properties, including photovoltaic performance.

Main Methods:

• Solvothermal reaction of TiO2 nanoparticles with carboxylic acids in an autoclave at 100°C.
• Characterization using powder X-ray diffraction, scanning electron microscopy, absorption spectra, Fourier transform infrared spectra, and thermogravimetric analysis.
• Tuning surface coverage by adjusting the modifier/TiO2 weight ratio.

Main Results:

• The solvothermal method achieved significantly higher modification efficiency than the immersion method.
• Carboxylic acid molecules bind to the TiO2 surface via a bidentate chelating mode.
• The crystalline phase, morphology, and surface coverage were controllable.
• Solvothermal modification improved the photovoltaic performance of TiO2 nanoparticles.

Conclusions:

• The solvothermal strategy offers a highly efficient route for TiO2 nanoparticle modification.
• The binding mechanism involves hydrogen bonding and dehydration-driven coordination.
• This method provides control over surface coverage and enhances functional properties, particularly for photovoltaic applications.