A review on the green and sustainable synthesis of silver nanoparticles and one-dimensional silver nanostructures

Abstract

The significance of silver nanostructures has been growing considerably, thanks to their ubiquitous presence in numerous applications, including but not limited to renewable energy, electronics, biosensors, wastewater treatment, medicine, and clinical equipment. The properties of silver nanostructures, such as size, size distribution, and morphology, are strongly dependent on synthesis process conditions such as the process type, equipment type, reagent type, precursor concentration, temperature, process duration, and pH. Physical and chemical methods have been among the most common methods to synthesize silver nanostructures; however, they possess substantial disadvantages and short-comings, especially compared to green synthesis methods. On the contrary, the number of green synthesis techniques has been increasing during the last decade and they have emerged as alternative routes towards facile and effective synthesis of silver nanostructures with different morphologies. In this review, we have initially outlined the most common and popular chemical and physical methodologies and reviewed their advantages and disadvantages. Green synthesis methodologies are then discussed in detail and their advantages over chemical and physical methods have been noted. Recent studies are then reviewed in detail and the effects of essential reaction parameters, such as temperature, pH, precursor, and reagent concentration, on silver nanostructure size and morphology are discussed. Also, green synthesis techniques used for the synthesis of one-dimensional (1D) silver nanostructures have been reviewed, and the potential of alternative green reagents for their synthesis has been discussed. Furthermore, current challenges regarding the green synthesis of 1D silver nanostructures and future direction are outlined. To sum up, we aim to show the real potential of green nanotechnology towards the synthesis of silver nanostructures with various morphologies (especially 1D ones) and the possibility of altering current techniques towards more environmentally friendly, more energy-efficient, less hazardous, simpler, and cheaper procedures.

Green Synthesis of Silver Nanoparticles Using Extract of Cilembu Sweet Potatoes (Ipomoea batatas L var. Rancing) as Potential Filler for 3D Printed Electroactive and Anti-Infection Scaffolds

“…However, the conventional synthesis method of AgNPs often involves the usage of toxic chemical reducing agents which are hazardous for humans (e.g., sodium borohydride, hydrazine), causing the resulting AgNPs to be deemed unsafe for biomedical use [28,29]. In an attempt to solve these issues, "green synthesis" methods have emerged as a viable and promising option to fabricate AgNPs, offering simple, cheap, rapid, and non-toxic premises [19,28,[30][31][32]. Instead of using chemical reducing agents, green synthesis methods utilize various biological entities such as plant extract [33][34][35], bacteria [36], and fungi [37] as both reducing and capping agents to produce a high yield of relatively uniform-sized metallic nanoparticles.…”

In Vitro and In Vivo Evaluation of Silver Nanoparticles Phytosynthesized Using Raphanus sativus L. Waste Extracts

“…In its "nano" form, silver was proven to be an important candidate for application in biomedicine, in applications such as antimicrobial, anticancer, or anti-diabetic therapy, wound repair and bone healing, or as biosensors [7]. Their application exceeds this area, silver nanoparticles (AgNPs) being used in different other areas, included, but not limited to catalysis, microelectronics, wastewater treatment, or renewable energy [8,9].…”

Phenothiazinium Photosensitizers Associated with Silver Nanoparticles in Enhancement of Antimicrobial Photodynamic Therapy

“…Their potential is used against multi-resistant bacteria and fungi that may cause serious infection in humans, animals, and plants. AgNPs present unique physical, chemical, and biological characteristics such as resistance, optical properties, high reactivity, and specific interactions with biomolecules and microorganisms [ 10 , 11 ]. The biological method uses living systems capable of producing AgNPs in a clean, non-toxic, and sustainable way.…”