Effect of Coupled Semiconductor System Treating Aqueous 4-Nitrophenol

Abstract

This article describes a method for treating aqueous 4-nitrophenol by mixing with TiO₂-SnO₂ coupled particles. The reactivity of single photocatalysis (TiO₂ and SnO₂ all as 1.2 g/L) is compared with that of mixing TiO₂-SnO₂ (0.6 g/L + 0.6 g/L) coupled particles. Aqueous 4-nitrophenol was treated by single photocatalysis or coupled semiconducting particles in a double-layer glass batch reactor using a 15W UV fluorescent tube at 25°C and 300 rpm for mixing. The results demonstrated that pH and the concentration of TiO₂ were the factors that most influenced the degradation characteristics, and that the system of TiO₂-SnO₂ coupled particles improved the efficiency of removal of refractory organic pollutants by 15%, by the inter-particle electron transfer (IPET) effect. The results showed that the degradation of aqueous 4-nitrophenol was 75% when coupled particles were used—better than the 60% obtained using single photocatalysis—with a reaction time of 120 min.

Keywords:

• 4-Nitrophenol
• Coupled semiconductor
• Interparticle electron transfer (IPET)

Acknowledgments

The authors would like to thank the Ministry of Economic Affairs of the Republic of China for financially supporting this research under Contract No. 91-EC-17-A-10-S1-0007.