Enhanced photocatalytic properties of CeO2/TiO2 heterostructures for phenol degradation

Herein, CeO2/TiO2 heterostructures are synthesized adopt a simple and profitable sol-gel technique. The nanostructures comprised of ultrafine and well-distributed CeO2 nanoparticles on the TiO2 surface. The obtained catalysts were characterized via X-ray diffraction, nitrogen adsorption, Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, photoluminescence spectroscopy, and ultraviolet (UV)-visible spectroscopy tests. The as-prepared heterostructures exhibited a visibly enhanced photodegradation performance using phenol(38 ppm) as the model of organic pollutants. The achieved degradation efficiency was 99.1% under UV-light irradiation for 120 min and the TOC removal was 81.31% when using CeO2/TiO2 as catalyst with the CeO2 loading of 0.5%. The enhanced property was ascribed to the formation of a heterojunction after coupling CeO2 with TiO2, which could capture the phenol molecules and improve the adsorption properties of the materials. Meanwhile, the heterostructures inhibited photogenic carriers recombination, thereby extending the optical response range. Furthermore, the as-prepared catalysts possessed favorable cycle performances and were reutilized for four cycles with insignificantly reduced property, the degradation rate were decreased slightly to 94.0% with a inappreciable decline in Ce and Ti leaching, suggesting it's preeminent stability and recyclability in the process of photocatalytic.

Automated summary

CeO2/TiO2 heterostructures were synthesized using a sol-gel technique, showing enhanced photodegradation performance and good stability for removing organic pollutants such as phenol in water. The heterojunction formed after coupling CeO2 with TiO2 improves adsorption properties, inhibits photogenic carriers recombination, and extends the optical response range, resulting in high degradation efficiency under UV-light irradiation. The catalysts also exhibited favorable cycle performances and recyclability with minimal decrease in degradation rate and leaching of Ce and Ti.