Photocatalytic Properties Of Graphene/Graphene Oxide Based Hybrid Nanomaterials

As a2-dimensional(2D) macromolecular sheet of carbon atoms material, apartfrom its2D large surface area, there are still several other excellent aspects ofgraphene such as great electronic properties and high transparency resulting from itsone atom thickness structure. Because of all these unique properties, graphene isdeemed as one of the most important materials in the world. Additionally, the hybridsbetween graphene/graphene oxide and semiconductor materials attract more and morescientific interests and show great potential applications. The synthesis of the hybridsbetween graphene/graphene oxide based semiconductor materials mainly includesmicro-mechanical exfoliation method, epitaxial growth method, chemical andelectro-chemical reduction of graphite oxide method and bottom-up organic synthesismethod.In this work, we used chemical reduction of graphite oxide method to synthesizereduced grapheme oxide (rGO), and as-synthesized material was proved by TEM. Wetchemical method was employed to obtain different ratios of ZnO-rGO composites andZnO-GO-Pd composites. The efficiency of as-prepared photocatalysts was tested, andthe factors that affect the efficiency of photocatalysts were also studied. Our resultsshow:1. Rather than directly participating in the photodegradation of dyes, the rGO orGO in photocatalysts preferentially accepts the photo-generated electrons as anelectron reservoir, significantly reduces the chances of the recombination, and effectively prolongs the lifetime of holes in ZnO nanoparticles(NPs), therefore greatlyenhancing the efficiency of hole-induced decomposition of dyes. Thephotodegradation process induced by ZnO-rGO photocatalyst still mainly occurs onthe surface of ZnONPs instead of rGO.2. When the weight ratio of ZnO and GO reached to0.85:0.15, the as synthesizedZnO-GO and ZnO-GO-Pd photocatalyst exhibit the optimum photocatalyticefficiency.3. With the assistance of noble metal Pd NPs, such kind of ZnO-GO-Pdnanocomposite exhibits even higher photocatalytic activity as compared to ZnO-GOcatalysts.