Synthesis, microstructure, and photocatalysis of In2O3 hollow particles

Indium oxide (In2O3) microspheres with hollow interiors have been prepared by a facile implantation route which enables indium ions released from indium-chloride precursors to implant into nonporous polymeric templates in C2Cl4 solvent. The templates are then removed upon calcination at 500 °C in air atmosphere, forming hollow In2O3 particles. Specific surface area (0.5–260 m2 g−1) and differential pore volume (7 × 10−9 to 3.8 × 10−4 m3 g−1 Å−1) of the hollow particles can be tailored by adjusting the precursor concentration. For the hollow In2O3 particles with high surface area (260 m2 g−1), an enhanced photocatalytic efficiency (up to ∼one-fold increase) against methylene blue (MB) dye is obtained under UV exposure for the aqueous In2O3 colloids with a dilute solids concentration of 0.02 wt.%.