Effect of Precursor on Antifouling Efficacy of Vertically-Oriented Graphene Nanosheets.

Karthika Prasad,Shailesh Kumar,Bastian Brockhoff,Gurinder Singh,Chaturanga Bandara,Kostya Ostrikov,Kateryna Bazaka

doi:10.3390/nano7070170

Abstract

Antifouling efficacy of graphene nanowalls, i.e., substrate-bound vertically-oriented graphene nanosheets, has been demonstrated against biofilm-forming Gram-positive and Gram-negative bacteria. Where graphene nanowalls are typically prepared using costly high-temperature synthesis from high-purity carbon precursors, large-scale applications demand efficient, low-cost processes. The advancement of plasma enabled synthesis techniques in the production of nanomaterials has opened a novel and effective method for converting low-cost natural waste resources to produce nanomaterials with a wide range of applications. Through this work, we report the rapid reforming of sugarcane bagasse, a low-value by-product from sugarcane industry, into high-quality vertically-oriented graphene nanosheets at a relatively low temperature of 400 °C. Electron microscopy showed that graphene nanowalls fabricated from methane were significantly more effective at preventing surface attachment of Gram-negative rod-shaped Escherichia coli compared to bagasse-derived graphene, with both surfaces showing antifouling efficacy comparable to copper. Attachment of Gram-positive coccal Staphylococcus aureus was lower on the surfaces of both types of graphene compared to that on copper, with bagasse-derived graphene being particularly effective. Toxicity to planktonic bacteria estimated as a reduction in colony-forming units as a result of sample exposure showed that both graphenes effectively retarded cell replication.

Highlights

Recent times have witnessed a significant increase in the use of nanomaterials, especially graphene, for a wide range of applications, ranging from electronics to agriculture and manufacturing [1,2,3]
Plasma-enhanced chemical vapour deposition (PECVD) has been used for the production of high-quality graphene nanosheets from a variety of resources [9]. In this low-temperature synthesis technique, the graphene can be grown directly on a wide range of desired substrates without any external heating or catalyst, and it is considered a promising method for controllable graphene synthesis [1,3,9,10,11]
Since the growth mechanism combines that of surface growth and precipitation of carbon from the catalyst bulk, the structure of resulting graphene may differ substantially from that deposited on Cu substrate [20,21]

Summary

Introduction

Recent times have witnessed a significant increase in the use of nanomaterials, especially graphene, for a wide range of applications, ranging from electronics to agriculture and manufacturing [1,2,3]. The morphology of graphene layers grown by means of plasma-enhanced synthesis has been intensity ratio of Raman spectra and show formation of thinner graphene layer on copper substrate and thicker ones on nickel substrate. The morphology of graphene layers grown by means of plasma-enhanced synthesis has been previously shown to depend on the chemistry and state of the precursor, as well as on the properties of the catalyst.

Results

Conclusion