Synthesis of SnO2TiO2 nanocomposite photocatalysts by supercritical fluid combination technology

Acrylic acid, acrylic ester and their ramification have developed quickly in recent years. However, their pro duction process produces a mass of waste water, which when released into the aquatic ecosystem, becomes a source of dramatic disturbance of aquat…

Synthesis of SnO2/TiO2 nanocomposite photocatalysts by supercritical fluid combination technology

SnO₂/TiO₂ nanocomposite photocatalysts were prepared from TiCl₄ and SnCl₄·5H₂O by supercritical fluid combination technique (SCFCT). This novel SCFCT is a combination of supercritical fluid drying method and sol-gel method. The XRD, TEM and FTIR results show that a new kind of active particle (Ti, Sn)O₂ has formed and there is no sign of SnO₂ crystals observed in the range of the doping concentration studied. The samples’ photocatalytic activity was evaluated by the degradation of acrylic acid. The results indicate that the SnO₂/TiO₂ nanocomposite photocatalysts prepared through SCFCT show significant improvement in catalytic activity as compared to pure TiO₂ or SnO₂/TiO₂ catalysts prepared by traditional drying (TD). The effect of H₂O₂ (0.167 v%) on the photodegradation was also investigated. After the addition of H₂O₂, the chemical oxygen demand (COD) of acrylic acid, which had been treated with (15.1 mol%) SnO₂/TiO₂ nanocomposite photocatalysts for 3 h, was reduced from 400–500 to 20 mg/L.