The green synthesis of nanoparticles is considered as safer route due to their cost effectiveness, environmental eco-friendly nature and simplicity in control of reaction parameters . Metal NPs have unique chemical and physical features, such as a large surface-to-volume ratio, that make them valuable in different sectors, including electronics, photonics, biomedicine, and catalysis [2–6]. Various types of nanomaterials such as zinc oxide, titanium oxide, gold, and silver have emerged  and are widely used in products that come into direct contact with the human body, such as detergents, cosmetics, tooth paste, in addition to medicinal and pharmaceutical uses . Among these silver NPs have proved to be most effective as it has good antimicrobial efficacy against bacteria, viruses and other eukaryotic microorganisms. Colloidal silver is of great interest due to its unique features such as high conductivity, chemical stability, biocompatibility, and catalytic and antibacterial activity . Silver nanoparticles have been regarded an essential topic of research due to their distinctive and powerful plasmon resonance in the visible region. Silver nanoparticles are used in a variety of applications, including solar energy absorption coatings and battery materials, optical receptors, chemical reaction catalysts, biolabelling, biomedical sensing and imaging, antimicrobial paint coatings, textiles, water treatment, medical equipment, HIV prevention and treatment [9–12] etc.
Traditional chemical procedures for synthesis of silver nanoparticles involve the use of ethylene glycol [13, 14], pyridine , and sodium borohydride . However, the chemicals used in these approaches can be toxic and extremely reactive, posing a risk to the environment and individuals, or the procedures are too costly to use on a large scale. Therefore, there is a need to develop low-cost, dependable, safe, and green approach to the synthesis of stable metal nanoparticles with controlled size and form. As a result, some novel methods for the synthesis of metal nanoparticles have recently been developed using biologically derived reducing agents like chitosan , glucose , and polysaccharides , microbes like bacteria and fungus [20, 21] and a variety of plant (seed, leaf, and tuber) extracts [22–27]. Among them, plant leaf extract-mediated biological processes have been extensively studied due to their low cost and simple technique. During the synthesis of nanoparticles, plant extracts may act as reducing and stabilizing agents. The chemical content of the plant extract has a big impact on the size and shape of nanoparticles (NPs), which could affect their catalytic activities for degrading organic effluents [28, 29].
In the past few decades, catalysis has become the backbone of large-scale chemical and petroleum sector production. New challenges and opportunities have arisen as a result of catalysis with the advancement of nanotechnology. The nanocatalysts have a lot of catalytic activity in various reactions such as oxidation, reduction, coupling, and electrochemical reactions.
Organic contaminants present in industrial or domestic wastewater effluents must be eliminated or destroyed before being discharged into the environment. Organic dyes are one of the most common types of pollutants found in textiles, plastics, medicine, and a variety of other industries, and their hazardous effects in waste water have long been a source of concern and, more recently, a major threat to the environment. They are difficult to degrade and are rarely removed from water by wastewater treatment systems or traditional methods such as adsorption, ultrafiltration, chemical, or electrochemical approaches . Therefore, a convenient degradation procedure is reductive degradation of toxic dyes using metal nanoparticles because of their unique physiochemical and electrical properties that are not present in bulk materials .
In this present investigation, Zingiber Officinale of the family of Zingiberaceae commonly known as ginger is used as a reducing agent for the synthesis of Ag NPs. Nanoparticles are frequently judged ineffective  due of their instability in aqueous medium, so in the present study surfactants are used to stabilize the NPs. A surfactant molecule is described as amphiphilic molecules that has a lengthy hydrophobic (water-hating or oil-loving) tail and a hydrophilic (water-loving) head. Depending on the type of surfactant, it greatly reduces particle size without affecting the shape .
The present study describes a cost-effective and environmentally friendly method for the synthesis of bare and surfactant capped silver nanoparticles using aqueous ginger root extract. Furthermore, the catalytic characteristics of these as-prepared bare and surfactant capped silver nanoparticles were investigated in the reduction of 4-nitrophenol and degradation of Methyl Orange.