Microwave-Assisted vs. Conventional Hydrothermal Synthesis, Morphology, Microstructure, and Surface Area Analysis of g-C3N4/MoS2 Nanocomposite

1. Introduction

Two-dimensional nanomaterial has a large specific area on the surface that provides a significant surface area for absorption onto a substrate surface, decreasing or eliminating friction between the contact surfaces (Vattikuti et al., 2015). Modern composites have been applied in a variety of innovative disciplines (Saxena et al., 2016). Molybdenum disulfide (commonly known to be MoS2) is now being investigated for a possible 2D TMD (transition metal chalcogenide) material due to its physical and chemical endurance in coatings. The lubricant's crystalline lamella structure regulates the rates at which it operates, with the sulphur lamella coupled by a weak VanDerWaal attraction, resulting as for a less friction (Berman et al., 2014). Layers of MoS2 slides with one another efficiently and aligned continuously parallel to the movement during slides, leading as a lubrication action. Lamellar is particularly resistant for asperity penetration because of the intense ionic interaction between sulphur and molybdenum atoms (Dallavalle et al., 2012). Pure MoS2, on the other hand, easily absorbs moisture in any humid atmosphere and can be oxidised in such an environment containing either molecular or atomic oxygen. This causes the coefficient of friction to rapidly increase and the lifetime of surface to decrease. Because of oxidation of MoS2, the frictional coefficient (COF) most often exceeds 0.2 sometimes (Cizaire et al., 2002, Curry et al., 2017, and Donnet et al., 1996). MoS2’s practical usage was limited oxidation issue. As a result, the superlubility of MoS2 could be improved at the atomic or molecular scale through proper structural or orientation ordering in a dry setting (humid free) or in a vacuum condition (Berman et al., 2018).

Molybdenum-disulfide is frequently combined with other material commonly grapheme and polyurethane (Bülbül et al., 2007), moreover metal like copper (Yao et al., 2004), chromium (Wang et al., 2018), titanium (Elianov et al., 2018), and aluminium (Lee et al., 2005), in order to overcome these constraints and provide improved properties. Improving the wearing life and COF of MoS2 used as a solid phase lubricant in various domains of applications is becoming a serious concern. Increasing the wear life of molybdenum-disulfide for its use as a solid lubricant in many fields while retaining a low coefficient of friction is currently regarded as being a serious challenge (Li et al., 2017). However, the high expense of the metal additives in MoS2 coatings limits their use. In theory, nonmetal materials such as layered type graphitic-carbon nitride, which is inexpensive, conveniently accessible and ecologically acceptable, can displace metal additives (Zhang et al., 2019 and Flores et al., 2014).

Currently, many disciplines use the CN that has low VanDerWaal forces in between tristriazine unit and its layers (Xu et al., 2018). gC3N4 is commonly added by Kumar et al., 2017 into lubrication media for improving frictional performance. Bonding of gC3N4 with octa-decylamine, for example, responsible in the forming boundary layer on the surface, that increased materials wearing refusal. Duan et al., 2018 chose gC3N4 as an oil ingredient as because it boosts wear resistance substantially. Zhu et al., 2015 created g-C3N4/Polyvinylidene fluoride composites and found that gC3N4 filler increased composite durability. Nanofillers are also widely employed in metal matrix composites (Gupta et al., 2021 and Saxena et al., 2021). Computational approaches also made mechanical and other types of study simpler to analyse (Saxena et al., 2021).