Bandgap modulation of graphene oxide and its application in the photocatalytic deposition of metallic nanoparticles
Assoc. Prof. Dr. Selmiye Alkan Gürsel (Thesis advisor)
Assoc. Prof. Dr. Önder Metin
Assist. Prof. Dr. Alp Yürüm
Date & Time: 31 July 2017 – 11.00 A.M.
Place: FENS G029
Keywords: Partially reduced graphene oxide, Platinum, Palladium, Gold, Silver, Metallic nanoparticles, Nanoclusters, Photocatalytic deposition, Partial reduction, Bandgap modulation.
In this project, a novel photocatalytic system for deposition of nano- and sub nano-sized metallic (platinum, palladium, gold and silver) particles on reduced graphene oxide has been developed. Partially reduced graphene oxide, a bandgap engineered form of graphene, has been used as the deposition platform and its chemical stability and bandgap modulation process has been discussed in great details. For the partial reduction, graphene oxide has been treated with highly concentrated sodium hydroxide solution and the reduction process has been continued (and monitored) until obtaining a stable product. We have also shown that graphene oxide which also exhibits semiconducting properties, isn’t a suitable photocatalyst materials mainly because of its chemical instability and considerable photocorrosion. An innovative reactor for pulsed UV illumination and continuous treatment of the reaction suspensions has been designed and fabricated during this thesis work which enables us to have precise control on the number of photoexcited electrons and consequently on the photodeposition of the metallic nanoparticles.