Microwave-Assisted Synthesis of SrTiO₃ Nanocuboids without TiCl₄

Area of Science:

• Materials Science
• Nanotechnology
• Catalysis

Background:

• Strontium titanate (STO) nanocuboids are promising supports for platinum nanoparticle (Pt/STO) catalysts.
• Commercialization requires scalable, sustainable, and cost-effective synthesis methods for STO nanocuboids.

Purpose of the Study:

• To investigate the synthesis of STO nanocuboids.
• To clarify how precursor mixture composition and heating methods influence STO nanoparticle morphology.
• To develop optimized synthesis routes for STO nanocuboids.

Main Methods:

• Synthesis of Sr-Ti-OH precursor mixtures using various Sr2+ and Ti4+ reagents.
• Hydrothermal treatment of precursor mixtures via convection- and microwave-assisted heating.
• Characterization of resulting STO nanoparticles to determine phase composition and morphology.

Main Results:

• STO phase stability in precursor mixtures depends on the Ti4+ source (TiCl4 vs. sol-gels).
• Convection heating yields STO nanocrystals, with nanocuboids forming only if STO precipitates beforehand.
• Microwave-assisted hydrothermal treatment rapidly heats precursors, enabling STO nanocuboid formation from diverse mixtures.
• Two successful microwave syntheses using TiCl4 and a water-stable Ti4+ complex are reported.

Conclusions:

• The choice of Ti4+ precursor and heating method significantly impacts STO nanoparticle morphology.
• Microwave-assisted hydrothermal synthesis offers a versatile and rapid route to STO nanocuboids.
• This work advances the development of scalable and sustainable synthesis for STO nanocuboid catalyst supports.