Synergistic effect of zinc oxide nanorods on the photocatalytic performance and the biological activity of graphene nano sheets

Abstract

In this work, decoration of the graphene surface with 5 wt. % ZnO nanorods (ZnO NRs), to ensure the potential photocatalytic performance of the formed nanocomposites, is demonstrated. Graphene oxide (GO) was synthesized with Hummer method followed by reduction to give reduced graphene oxide (RGO). The adjustable nanocompositing exhibited long-sought workability not only in in-situ incorporation of nanorods while reduction of graphene oxide (IZG) but also in ex-situ mixing of RGO or GO with the nanorods, (EZG) and (ZGO) respectively. The demineralization of synthetic wastewater has been evaluated by chemical oxygen demand and the obtained nanocomposites possess enhanced photocatalytic activities with 30 % and 35% over pure RGO and GO, respectively. This higher efficiency could be attributed to the synergistic effect between ZnO and the planner structure of graphene sheets which developed unprecedented polycrystalline structure. Also, the results proved that even the RGO or GO have played a dual function in photocatalysis, adsorption, and degradation. Also, the bactericidal effect of the prepared samples was studied against deleterious microorganisms. The findings of this work pave the way for the new generation of highly efficient photocatalysts based graphene with economic attraction and environmental impact.

Synthesis, Characterization, and Photocatalytic Performance of ZnO–Graphene Nanocomposites: A Review

“…Recently, Ghanem et al reported the ex situ technique through the mixing of GO with ZnO nanorods (EZG) and the in situ process by reducing GO in the presence of ZnO nanorods (IZG) [94]. For IZG, ZnO nanorods facilitate GO's exfoliation during the reduction process as a few monolayers of rGO were obtained, and the nanorods were homogeneously dispersed over the nanosheets.…”

“…This energy allows us to know the elemental composition of the sample. As mentioned, studies of chemical composition are useful to identify different phases in composite characterization, in particular, to identify the presence of ZnO in ZnO-graphene hybrids and to know the relative percentage of each element in the sample being analyzed [94,[124][125][126].…”

Novel Structures and Applications of Graphene-Based Semiconductor Photocatalysts: Faceted Particles, Photonic Crystals, Antimicrobial and Magnetic Properties

“…The nanohybrids of graphene with metals and metal oxides have also been proposed in order to obtain the efficient antimicrobial agents, e.g., Ag [113][114][115][116][117], Ti [118], NiO [119], ZnO [120][121][122][123] and TiO 2 [124][125][126], as summarized in Table 3. Silver deposition on GO/rGO significantly enhances the antimicrobial activity (against E. coli, S. aureus, oral pathogens C. albicans, Lactobacillus acidophilus, Streptococcus mutans, and Aggregatibacter actinomycetemcomitans) due to the intrinsic activity of silver [113][114][115][116][117].…”

Efficient and Rapid Photocatalytic Degradation of Methyl Orange Dye Using Al/ZnO Nanoparticles

“…Therefore, it has become an important issue to extend the optical absorption of ZnO from the UV region to visible region for photocatalytic applications. Several methods have been proposed to improve properties of ZnO by controlling the size and morphology of particles [ 38 , 39 ], doping with metals and nonmetals [ 40 , 41 , 42 , 43 ] and coupling with other semiconductor catalysts [ 44 , 45 , 46 ]. The surface defects by introducing metal elements have been reported to play an important role in improving photocatalytic activities over a wide range of wavelengths by reducing the bandgap energy.…”