New frontiers in the biosynthesis of metal oxide nanoparticles and their environmental applications: an overview

Abstract

Nanotechnology has become a promising and emerging field of research in creating and modifying nanomaterials for different applications. Nanoparticles are considered to be the basic element of nanotechnology as they are the primary source of several nanostructured materials. During the last few decades, several metal oxide nanoparticles (NPs) were synthesized and their applications were investigated in various fields of science and technology, including biomedical, environmental, energy and agricultural practices. Moreover, metal oxide NPs have been synthesized by physical and chemical methods, while the chemical method used different chemicals as reducing and stabilizing agents. However, the wet chemical synthesis strategy become responsible for various biological and environmental risks due to the toxicity of used chemicals. Recently, biological synthesis of metal oxide nanoparticles using plants, algae, and microbes as a source of precursor material has emerged as a green and safe method. Additionally, the green synthesized metal oxide nanoparticles have shown a pivotal role in several applications such as nano-adsorbents, nano-membranes, photocatalysts and disinfection of wastewater from microbes. In this review, we present an overview of the biosynthesis of metal oxide nanoparticles such as; ZnO, CeO 2 , TiO 2 , CdO, CuO, Fe 3 O 4 , SnO 2 , NiO etc. Their method of characterization and properties is also discussed. Finally, their applications towards environmental protection is presented with particular attention to water treatment and remediation.

Synthesis of TiO2 nanoparticles by chemical and green synthesis methods and their multifaceted properties

“…Nanomaterials belongs to the range of below 100 nm has unique chemical, physical, electrical, and mechanical properties and also diversely utilized in the field of medical, biotechnology, microbiology, pharmaceutics and chemistry, engineering, inexpensive catalyst, cytotoxicity study, etc. [1][2][3]. Owing to its large surface area, nanomaterial synthesis methods are classified into the physical and chemical methods.…”

Microwave assisted synthesis of zinc oxide (ZnO) nanoparticles in a noble approach: utilization for antibacterial and photocatalytic activity

“…Recently metal and metal oxide nanoparticles have increased the interest to be used in many areas of technology [1][2][3][4]. Among various metal oxides nanoparticles, zinc oxide (ZnO) has received much attention due to its unique physical, chemical and effective biological properties [5].…”

Nanoforms of essential metals: from hormetic phytoeffects to agricultural potential

“…Therefore, the biogenic approaches, which utilize microbial or plant sources, have emerged recently as novel and potential methods for producing NPs. The rapid development of the synthesis procedures brought a significant increase in the number of nanomaterials with desired properties being manufactured ( Gebre and Sendeku, 2019 ).…”