Further studies of photodegradation and photocatalytic hydrogen production over Nafion-coated Pt/P25 sensitized by rhodamine B

Abstract

TiO2 is an excellent photocatalyst in photodegradation and hydrogen production. Herein, through simple modification of Pt/TiO2 (P25) by Nafion (Nf), photocatalyst Nf/Pt/P25 was prepared and characterized. Photodegradation of rhodamine B (RhB) and photocatalytic hydrogen production over the Nf/Pt/P25 were investigated and compared with those of Nf/P25, P25 and Pt/P25. The results showed the Nf coating caused remarkable improvements in RhB degradation and hydrogen production with RhB as sensitizer. Especially, for the first time, the influence of sacrificial reagent (SR) on hydrogen production performance was studied in detail and the results indicated replacing disodium ethylene-diamine tetraacetate (EDTA) used in literature with triethanolamine (TEOA) leads to a significant enhancement in activity. The H2-evolving rate of RhB-Nf/Pt/P25-TEOA system is up to 12 times that of RhB-Nf/Pt/P25-EDTA. Besides, other H2 evolution parameters were optimized and cycling H2 evolution tests over the Nf/Pt/P25 were conducted. The results confirmed that concurrent H2 evolution and RhB degradation can be achieved even with very few RhB. Finally, reasons for the enhanced H2 production performance were proposed. It addressed the importance of selecting a suitable SR and will be very helpful for further work on photocatalytic hydrogen production and photodegradation.