A Time-Interval Strategy to Prepare Porous SiO₂ Spheres with Adjustable Core-Shell Ratio for Multiple Guest Loading

Area of Science:

• Materials Science
• Nanotechnology
• Environmental Science

Background:

• Porous microspheres are crucial for adsorbing pollutants.
• Controlling pore size and distribution is key for efficient material loading.
• Existing methods often lack control over microsphere architecture.

Purpose of the Study:

• To develop a method for preparing multilevel porous silica (SiO2) microspheres with adjustable core-shell ratios.
• To investigate the relationship between preparation parameters and microsphere properties.
• To evaluate the potential of these microspheres for pollutant removal in wastewater.

Main Methods:

• Silica microsphere synthesis via a sol-gel process.
• Tuning core-shell ratio by controlling the time interval between hydrolysis and organic solvent addition.
• Characterization of specific surface area, pore size, and pore volume.
• Demonstration of co-loading platinum nanoparticles and dye molecules.

Main Results:

• Multilevel porous SiO2 microspheres with adjustable core-shell ratios were successfully synthesized.
• Specific surface area ranged from 543.2 to 992.9 m2 g-1.
• Average pore diameter varied from 2.3 to 5.7 nm with a high pore volume of 0.91 cm3 g-1.
• Hierarchical SiO2 microspheres were produced on a large scale.

Conclusions:

• The preparation method allows for precise control over SiO2 microsphere architecture.
• The tunable porous microspheres exhibit excellent performance for co-loading nanoparticles and dye molecules.
• These findings highlight the potential of SiO2 microspheres for treating pollutants in printing and dyeing wastewater.