Engineering Commercial TiO₂ Powder into Tailored Beads for Efficient Water Purification

Area of Science:

• Materials Science
• Environmental Chemistry
• Nanotechnology

Background:

• Powdered photocatalysts face challenges in handling and reusability.
• Alginate biopolymer offers a matrix for stabilizing nanoparticles and metal chelation.
• Titanium dioxide (TiO2) is a well-established photocatalyst, but its application can be improved.

Purpose of the Study:

• To develop robust, easy-to-handle photocatalytic materials using alginate-encapsulated TiO2 nanoparticles.
• To enhance photocatalytic efficiency by incorporating copper nanoparticles (Cu) and utilizing pyrolytic carbon residuals.
• To evaluate the performance of the novel photocatalysts in degrading Methyl Orange (MO) in aqueous solutions.

Main Methods:

• Dispersion and stabilization of Degussa P25 TiO2 nanoparticles in alginate.
• Formation of ceramic beads via pyrolytic or calcination-sintering procedures with copper decoration.
• Characterization using N2 porosimetry, SEM, XRD, and batch experiments for MO degradation studies.

Main Results:

• Alginate-based ceramic beads exhibited enhanced mechanical properties and handling compared to powders.
• Pyrolytic carbon residuals improved TiO2 nanoparticle adhesion and MO adsorption capacity.
• Copper nanoparticle decoration and optimized synthesis led to ~50% MO removal and 80% overall rejection within 3 hours, with good reusability over four cycles.

Conclusions:

• Alginate-based ceramic beads incorporating TiO2 and Cu nanoparticles offer a promising solution for efficient water treatment.
• The synthesis and heat treatment conditions significantly influence the photocatalytic performance and material properties.
• The developed photocatalysts demonstrate high adsorption capacity, efficient degradation of organic pollutants, and good recyclability.