Highly Durable Antimicrobial Tantalum Nitride/Copper Coatings on Stainless Steel Deposited by Pulsed Magnetron Sputtering

Highly durable and antimicrobial tantalum nitride/copper (TaN/Cu) nanocomposite coatings were deposited on D-9 stainless steel substrates by pulsed magnetron sputtering. The Cu content in the coating was varied in the range of 1.42–35.42 atomic % (at.%). The coatings were characterized by electron probe microanalyzer, X-ray diffraction, scanning electron microscope and atomic force microscope. The antibacterial properties of the TaN/Cu coatings against gram-negative Pseudomonas aeruginosa were evaluated using a cell culture test. The peak hardness and Young’s modulus of TaN/Cu with 10.46 at.% Cu were 24 and 295 GPa, respectively, which amounted to 15 and 41.67% higher than Cu-free TaN. Among all, TaN/Cu with 10.46 at.% exhibited the lowest friction coefficient. The TaN/Cu coatings exhibited significantly higher antibacterial activity than Cu-free TaN against Pseudomonas aeruginosa. On TaN, the bacterial count was about 4 × 106 CFU, whereas it was dropped to 1.2 × 102 CFU in case of TaN/Cu with 10.46 at.% Cu. The bacterial count was decreased from 9 to 6 when the Cu content increased from 25.54 to 30.04 at.%. Live bacterial cells were observed in the SEM images of TaN, and dead cells were found on TaN/Cu. Overall, TaN/Cu with 10.46 at.% Cu was found to be a potential coating composition in terms of higher antimicrobial activity and mechanical durability

Recent development on carbon based heterostructures for their applications in energy and environment: A review

Nanostructured carbon based materials with unique and tunable properties make them to be utilized for various applications in different forms especially for energy and environmental applications. Carbon is a distinctive chemical element which has superior properties such as porous structure, low cost, resistance to basic and acidic conditions, easy accessibility, low density, good recycling properties, more abundant and ability to combine with other chemical elements in different ways. In this review, we have critically assessed the recent developments in carbon based heterostructures for their applications in energy and environment. Special consideration has been paid on the applications in dye-sensitized solar cells, hydrogen evolution reaction, oxygen evolution reaction, Li-ion battery, supercapacitor, photocatalysis for the degradation of organic pollutants, electrochemical/bio sensors and biomedical applications. Finally, the challenges and future developments of carbon based heterostructures for applications in energy and environment are also outlined. (C) 2018 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserve