Developing sustainable Zn-MWCNTs composite coatings using electrochemical co-deposition method: Tribological and surface wetting behavior

Abstract

Carbon nanotube (CNT) nanofillers are a part of carbon allotrope family materials with numerous and effective features. Multiple CNTs nested one another is a low-cost and scalable category of CNTs, known as multi-walled CNTs (MWCNTs), which are well-stablised for their excellent mechanical, electrical and thermal properties. In this present work, MWCNTs nanofiller embedded Zn matrix (Zn-MWCNTs) composite coatings were fabricated by adding the different concentrations of MWCNTs (0.5, 0.1 and 0.2 g/L) in the acidic electrolyte bath using electrochemical co-deposition route with uniform embedment. The prepared composite coatings were characterised using advanced characterisation techniques (XRD, FESEM and EDS) for their obtained surface morphology and microstructures. All Zn-MWCNTs composite coatings exhibited enhanced tribo-mechanical performance compared to pure Zn coatings. Zn-MWCNT (0.2 g/L) composite coating exhibited the highest average microhardness value of 119 HV and minimum wear rate of 12.5 × 10−3 mm3N−1m−1 among all the prepared composite coatings, which attributed to the synergistic effect of microstructural refinement and superior mechanical properties of MWCNTs. Surface wetting studies reveal that MWCNTs play an important role in increasing hydrophobicity in terms of contact angle, which increased by 1.93 times for Zn-MWCNT (0.2 g/L) composite coating. The present work may be helpful for facile fabrication of low-cost biocidal Zn-MWCNTs nanocomposite coating.