scholarly journals Green Synthesis and Applications of ZnO and TiO2 Nanostructures

Molecules ◽  
2021 ◽  
Vol 26 (8) ◽  
pp. 2236
Author(s):  
Rosana A. Gonçalves ◽  
Rosimara P. Toledo ◽  
Nirav Joshi ◽  
Olivia M. Berengue

Over the last two decades, oxide nanostructures have been continuously evaluated and used in many technological applications. The advancement of the controlled synthesis approach to design desired morphology is a fundamental key to the discipline of material science and nanotechnology. These nanostructures can be prepared via different physical and chemical methods; however, a green and ecofriendly synthesis approach is a promising way to produce these nanostructures with desired properties with less risk of hazardous chemicals. In this regard, ZnO and TiO2 nanostructures are prominent candidates for various applications. Moreover, they are more efficient, non-toxic, and cost-effective. This review mainly focuses on the recent state-of-the-art advancements in the green synthesis approach for ZnO and TiO2 nanostructures and their applications. The first section summarizes the green synthesis approach to synthesize ZnO and TiO2 nanostructures via different routes such as solvothermal, hydrothermal, co-precipitation, and sol-gel using biological systems that are based on the principles of green chemistry. The second section demonstrates the application of ZnO and TiO2 nanostructures. The review also discusses the problems and future perspectives of green synthesis methods and the related issues posed and overlooked by the scientific community on the green approach to nanostructure oxides.

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6389
Author(s):  
Kaushik Kumar Bharadwaj ◽  
Bijuli Rabha ◽  
Siddhartha Pati ◽  
Tanmay Sarkar ◽  
Bhabesh Kumar Choudhury ◽  
...  

Gold nanoparticles (AuNPs) have been widely explored and are well-known for their medical applications. Chemical and physical synthesis methods are a way to make AuNPs. In any case, the hunt for other more ecologically friendly and cost-effective large-scale technologies, such as environmentally friendly biological processes known as green synthesis, has been gaining interest by worldwide researchers. The international focus on green nanotechnology research has resulted in various nanomaterials being used in environmentally and physiologically acceptable applications. Several advantages over conventional physical and chemical synthesis (simple, one-step approach to synthesize, cost-effectiveness, energy efficiency, and biocompatibility) have drawn scientists’ attention to exploring the green synthesis of AuNPs by exploiting plants’ secondary metabolites. Biogenic approaches, mainly the plant-based synthesis of metal nanoparticles, have been chosen as the ideal strategy due to their environmental and in vivo safety, as well as their ease of synthesis. In this review, we reviewed the use of green synthesized AuNPs in the treatment of cancer by utilizing phytochemicals found in plant extracts. This article reviews plant-based methods for producing AuNPs, characterization methods of synthesized AuNPs, and discusses their physiochemical properties. This study also discusses recent breakthroughs and achievements in using green synthesized AuNPs in cancer treatment and different mechanisms of action, such as reactive oxygen species (ROS), mediated mitochondrial dysfunction and caspase activation, leading to apoptosis, etc., for their anticancer and cytotoxic effects. Understanding the mechanisms underlying AuNPs therapeutic efficacy will aid in developing personalized medicines and treatments for cancer as a potential cancer therapeutic strategy.


2019 ◽  
Vol 118 (7) ◽  
pp. 59-66
Author(s):  
S. M. Sasikanth ◽  
Ganapathi Raman . R

Nanocomposite, a multiphase solid material which is having the phases of one, two, or three dimensions less than 100 nanometers. These materials have the physical and chemical properties which depend on the morphology and the interfacial characteristics of the component materials. Metal oxide nanocomposites have proven themselves their importance in the present time with a wide variety of applications in every industrial sector. Wet chemical methods are one of the simplest routes for the synthesis of the metal oxide nanocomposites, and they are cost effective as well. For the synthesis of the complex matrix-based metal oxide nanocomposites, Co-precipitation is the method used. The simple synthesis methods make them unique material for different applications. This review paper discusses the synthesisof metal oxide nanocomposites and their applications.


2021 ◽  
Vol 11 (22) ◽  
pp. 11075
Author(s):  
Angela Spoială ◽  
Cornelia-Ioana Ilie ◽  
Luminița Narcisa Crăciun ◽  
Denisa Ficai ◽  
Anton Ficai ◽  
...  

The interconnection of nanotechnology and medicine could lead to improved materials, offering a better quality of life and new opportunities for biomedical applications, moving from research to clinical applications. Magnetite nanoparticles are interesting magnetic nanomaterials because of the property-depending methods chosen for their synthesis. Magnetite nanoparticles can be coated with various materials, resulting in “core/shell” magnetic structures with tunable properties. To synthesize promising materials with promising implications for biomedical applications, the researchers functionalized magnetite nanoparticles with silica and, thanks to the presence of silanol groups, the functionality, biocompatibility, and hydrophilicity were improved. This review highlights the most important synthesis methods for silica-coated with magnetite nanoparticles. From the presented methods, the most used was the Stöber method; there are also other syntheses presented in the review, such as co-precipitation, sol-gel, thermal decomposition, and the hydrothermal method. The second part of the review presents the main applications of magnetite-silica core/shell nanostructures. Magnetite-silica core/shell nanostructures have promising biomedical applications in magnetic resonance imaging (MRI) as a contrast agent, hyperthermia, drug delivery systems, and selective cancer therapy but also in developing magnetic micro devices.


2021 ◽  
Vol 335 ◽  
pp. 03008
Author(s):  
Khizar Mushtaq ◽  
Pui May Chou ◽  
Chin Wei Lai

Tungsten being a transition element, forms oxide compounds of various oxidation states that enables it to form nanocolloids of tungsten oxide dihydrate. Multiple methods have been used in recent years to synthesize nano tungsten oxide dihydrate, including sol-gel synthesis, electrochemical deposition, hydrothermal synthesis and anodization. However, a universally accepted synthesis method for this material is not offered. The most appropriate method and its corresponding processing parameters for the synthesis of nano tungsten oxide dihydrate colloids were presented in the present study. The objective of the present study was to investigate the effect of processing parameters, i.e. applied voltage, temperature and anodizing duration on the particle size of nanocolloids. It is found that anodization is the easiest, efficient, and cost-effective method to synthesize the colloidal solution of nano tungsten oxide dihydrate. Conducting the synthesis at room temperature at a voltage of 50 V for 60 minutes yields the product with particle size of 40 – 60 nm, which can be used in wide array of applications. This paper also highlights the research gaps for future work and gives recommendations to extend this study particularly for the industrial application of tungsten oxide.


2020 ◽  
Vol 36 (6) ◽  
pp. 1154-1160
Author(s):  
G. DEEPA ◽  
M. JEYARAJ ◽  
P. N. Magudeswaran

On account of industrialization and increasing population, the water bodies get polluted by means of degradable and non-degradable substances. In 21st century, it is necessary to maintain a healthy environment especially water bodies for the survival of not the aquatic animals but also for healthy human life. Recent advances suggest that the issues related to water quality could be resolved by using nanoparticles and nano-filtration membrane methods from the development of nanotechnology. In this research, attempt to remove heavy metals from Chithrapuzha River water at Cochin bar mouth (S1) and Fact barge jetty (S2) using Fe2O3 prepared via green synthesis using Egg albumin and Aloe vera. Our results provoke that, the synthesis of Fe2O3 nanoparticle is cost-effective and eco-friendly and also good in nano-regime. Results of filtration studies showed that Fe2O3 nanoparticles remove heavy metals from Chithrapuzha River water and also increases the DO content which helps the survival of aquatic life.


Author(s):  
Totka Dodevska ◽  
Dobrin Hadzhiev ◽  
Ivan Shterev ◽  
Yanna Lazarova

Recently, the development of eco-friendly, cost-effective and reliable methods for synthesis of metal nanoparticles has drawn a considerable attention. The so-called green synthesis, using mild reaction conditions and natural resources as plant extracts and microorganisms, has established as a convenient, sustainable, cheap and environmentally safe approach for synthesis of a wide range of nanomaterials. Over the past decade, biosynthesis is regarded as an important tool for reducing the harmful effects of traditional nanoparticle synthesis methods commonly used in laboratories and industry. This review emphasizes the significance of biosynthesized metal nanoparticles in the field of electrochemical sensing. There is increasing evidence that green synthesis of nanoparticles provides a new direction in designing of cost-effective, highly sensitive and selective electrode-catalysts applicable in food, clinical and environmental analysis. The article is based on 157 references and provided a detailed overview on the main approaches for green synthesis of metal nanoparticles and their applications in designing of electrochemical sensor devices. Important operational characteristics including sensitivity, dynamic range, limit of detection, as well as data on stability and reproducibility of sensors have also been covered. Keywords: biosynthesis; green synthesis; nanomaterials; nanotechnology; modified electrodes


2013 ◽  
Vol 756 ◽  
pp. 106-111 ◽  
Author(s):  
Selvaraj Arokiyaraj ◽  
Udaya Prakash Nyayiru Kannaian ◽  
Vijay Elakkya ◽  
T. Kamala ◽  
S. Bhuvaneswari ◽  
...  

The aim of the present study is to synthesize silver nanoparticles, using an aqueous floral extract of common Lotus, i.e Nelumbo nucifera. The synthesized nanoparticles were characterized using UV, TEM, EDX, AFM & XRD. The synthesized AgNPs were confirmed due to the colour change from colourless to reddish brown just after the addition of the aqueous floral extract of Nelumbo nucifera. The UV results of AgNPs showed the excitation of surface Plasmon resonance band at 427 nm. TEM results showed that the synthesized AgNPs were uniformed; monodispersed,spherical in shape and the particle size were found to be 77.81 ± 3.54 nm. EDX spectrum of AgNPs confirms strong signals from Ag (64%) and other elements such as C, O and Cl. The morphology of the synthesized AgNPs by AFM analysis resembled the TEM micrograph. The crystalline nature of the AgNPs was confirmed by XRD. The present study concludes that the aqueous floral extract of Nelumbo nucifera could be used as an effective reducing agent for the synthesis of AgNP. The green synthesis ofsilver nanoparticles is non-toxic and cost-effective and thus remains to be an alternative method to other physical and chemical reduction methods.


2019 ◽  
Vol 25 (24) ◽  
pp. 2650-2660 ◽  
Author(s):  
Rajasree Shanmuganathan ◽  
Indira Karuppusamy ◽  
Muthupandian Saravanan ◽  
Harshiny Muthukumar ◽  
Kumar Ponnuchamy ◽  
...  

Generally, silver is considered as a noble metal used for treating burn wound infections, open wounds and cuts. However, the emerging nanotechnology has made a remarkable impact by converting metallic silver into silver nanoparticles (AgNPs) for better applications. The advancement in technology has improved the synthesis of NPs using biological method instead of physical and chemical methods. Nonetheless, synthesizing AgNPs using biological sources is ecofriendly and cost effective. Till date, AgNPs are widely used as antibacterial agents; therefore, a novel idea is needed for the successful use of AgNPs as therapeutic agents to uncertain diseases and infections. In biomedicine, AgNPs possess significant advantages due to their physical and chemical versatility. Indeed, the toxicity concerns regarding AgNPs have created the need for non-toxic and ecofriendly approaches to produce AgNPs. The applications of AgNPs in nanogels, nanosolutions, silver based dressings and coating over medical devices are under progress. Still, an improvised version of AgNPs for extended applications in an ecofriendly manner is the need of the hour. Therefore, the present review emphasizes the synthesis methods, modes of action under dissipative conditions and the various biomedical applications of AgNPs in detail.


2015 ◽  
Vol 1088 ◽  
pp. 371-376 ◽  
Author(s):  
Xia Zhang ◽  
Cui Xia Yan ◽  
Rong Feng Guan

Spherical YAG:Ce3+phosphors were synthesized by three different routes namely sol-gel method, co-precipitation method and solvethermal method. The microstructure, crystallization and luminescent properties of the phosphors were studied in order to find the best processing parameter for spherical shape and good luminescence properties of YAG:Ce3+phosphor. Adding citric acid to the precursor solution resulted in the formation of spherical particles in sol-gel method. YAG:Ce3+phosphor made by co-precipitation method was separated with PEG2000, and its spherical particles of size was around 500nm. The hydro-thermal method could get perfect spherical appearance, but it needed heat treatment improve the luminescence property.


Sensors ◽  
2021 ◽  
Vol 21 (17) ◽  
pp. 5758
Author(s):  
Izabela Constantinoiu ◽  
Cristian Viespe

The development of hydrogen sensors has acquired a great interest from researchers for safety in fields such as chemical industry, metallurgy, pharmaceutics or power generation, as well as due to hydrogen’s introduction as fuel in vehicles. Several types of sensors have been developed for hydrogen detection, including resistive, surface acoustic wave, optical or conductometric sensors. The properties of the material of the sensitive area of the sensor are of great importance for establishing its performance. Besides the nature of the material, an important role for its final properties is played by the synthesis method used and the parameters used during the synthesis. The present paper highlights recent results in the field of hydrogen detection, obtained using four of the well-known synthesis and deposition methods: sol-gel, co-precipitation, spin-coating and pulsed laser deposition (PLD). Sensors with very good results have been achieved by these methods, which gives an encouraging perspective for their use in obtaining commercial hydrogen sensors and their application in common areas for society.


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