A New Green Method for the Preparation of Titanium dioxide-Graphene Composite Using Cyclodextrin as a Linker with Enhanced Photoexcited Electron Transfer and Photocatalytic Properties

摘要

In this article, we report a titanium dioxide-graphene (TiO_2-CD-GN) composite from TiO_2 and reduced graphene oxide (rGO) using a new green method. TiO_2 nanoparticles are anchored onto graphene nanosheets (GNs) through β-cyclodextrin (CD) molecules using sun light irradiation. In this method, graphene is directly incorporated as rGO rather than GO into the composite. The prepared TiO_2-CD-GNs exhibits reduced charge recombination compared to that of the bare TiO_2, indicating effective charge separation. The composite with 0.5% of rGO (TiO_2-CD-GNs0.5) shows ～3 times higher activity to that of the bare TiO_2 for the photode-gradation of methylene blue. The TiO_2-CD-GNs0.5 displays enhanced electron transfer. In the visible light photodegrada-tion of 4-chlorophenol, TiO_2-CD-GNsl exhibits the highest photocatalytic activity compared to that of the composites and bare TiO_2. Catalytic activity of the reused catalyst remains the same (62% of the initial value) from the second cycle to the next 7 cycles studied.