**1. Introduction**

Plasma technology has been involved in various biomedical and environmental applications for quite a long time. From the treatment of cancer to the polluted water, its involvement increases day by day to humankind. Moreover, plasma has also been immensely engaged in the fabrication of high-quality nanomaterials [1]. Various methods have been employed to generate the plasma both in the nonthermal and thermal conditions. Amongst them, Plasma – Liquid Interaction (PLI) gains a lot of attention as it involves both the physical and chemical processes simultaneously [2]. It offers single-step, rapid and large-scale synthesis of uniform nanomaterials with different shapes and sizes [3]. One of the advantages of PLI is that it does not require any external reducing and stabilising chemical agents, so a few purification steps can be avoided before applying in any application. The reactive species form during the generation of plasma act as the reducing or oxidising agents. Moreover, it does not require water cool vacuum chambers or pumping systems. PLI offers two effective ways for nanomaterial synthesis. The first one is from the electrode material by generating plasma between two electrodes placed in a liquid. This process is termed as In-Liquid Plasma or solution plasma. Here, nanomaterials can also synthesised using specific metal precursor solutions. Hence, both the electrode material and the precursor solution can be the source of nanomaterial formation. In the second one, nanomaterials are fabricated by generating plasma above a liquid surface. Here, one electrode is placed above the
