Green synthesis of ZrO2 nanoparticles and nanocomposites for biomedical and environmental applications: a review.

Pollution and diseases such as the coronavirus pandemic (COVID-19) are major issues that may be solved partly by nanotechnology. Here we review the synthesis of ZrO2 nanoparticles and their nanocomposites using compounds from bacteria, fungi, microalgae, and plants. For instance, bacteria, microalgae, and fungi secret bioactive metabolites such as fucoidans, digestive enzymes, and proteins, while plant tissues are rich in reducing sugars, polyphenols, flavonoids, saponins, and amino acids. These compounds allow reducing, capping, chelating, and stabilizing during the transformation of Zr4+ into ZrO2 nanoparticles. Green ZrO2 nanoparticles display unique properties such as a nanoscale size of 5-50 nm, diverse morphologies, e.g. nanospheres, nanorods and nanochains, and wide bandgap energy of 3.7-5.5 eV. Their high stability and biocompatibility are suitable biomedical and environmental applications, such as pathogen and cancer inactivation, and pollutant removal. Emerging applications of green ZrO2-based nanocomposites include water treatment, catalytic reduction, nanoelectronic devices, and anti-biofilms.

Green synthesis of ZrO2 nanoparticles and nanocomposites for biomedical and environmental applications: a review

Pollution and diseases such as the coronavirus pandemic (COVID-19) are major issues that may be solved partly by nanotechnology. Here we review the synthesis of ZrO2 nanoparticles and their nanocomposites using compounds from bacteria, fungi, microalgae, and plants. For instance, bacteria, microalgae, and fungi secret bioactive metabolites such as fucoidans, digestive enzymes, and proteins, while plant tissues are rich in reducing sugars, polyphenols, flavonoids, saponins, and amino acids. These compounds allow reducing, capping, chelating, and stabilizing during the transformation of Zr4+ into ZrO2 nanoparticles. Green ZrO2 nanoparticles display unique properties such as a nanoscale size of 5–50 nm, diverse morphologies, e.g. nanospheres, nanorods and nanochains, and wide bandgap energy of 3.7–5.5 eV. Their high stability and biocompatibility are suitable biomedical and environmental applications, such as pathogen and cancer inactivation, and pollutant removal. Emerging applications of green ZrO2-based nanocomposites include water treatment, catalytic reduction, nanoelectronic devices, and anti-biofilms.

A Review of Recent Progress on Photocatalytic Carbon dioxide Reduction into Sustainable Energy Products using Carbon Nitride

Worldwide air pollution caused a severe damage to ecosystem by the emission of greenhouse gases. The emission percentage of principal greenhouse gas- carbon dioxide, other gases methane, fluorinated gases and nitrous oxide still not decreased even after the Covid-19 pandemic lockdown. In this regard, many research works were reported on the techniques involved to convert the principal greenhouse gas- carbon dioxide into useful sustainable energy fuel. The advancement in the field of nanoscience and nanotechnology, nanomaterials are used as a photocatalyst to produce energy from greenhouse gas. Carbon nitride is a semiconductor with high stability to produce quantum confinement and reducing the recombination rate of charges, with the introduction of external nanoparticles. It was available in the reports hybrid carbon nitride nanocomposite was employed to reduce the carbon dioxide into valuable products. This review article emerged with an interest towards the carbon nitride’s activeness in the visible region as an effective photocatalyst in the photoreduction of carbon dioxide. Past six years research progress in developing carbon nitride's features to enhance its role in energy production by performing carbon dioxide reduction were given in detail.

SARS-CoV-2 variants and environmental effects of lockdowns, masks and vaccination: a review.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is continuously evolving and four variants of concern have been identified so far, including Alpha, Beta, Gamma and Delta variants. Here we review the indirect effect of preventive measures such as the implementation of lockdowns, mandatory face masks, and vaccination programs, to control the spread of the different variants of this infectious virus on the environment. We found that all these measures have a considerable environmental impact, notably on waste generation and air pollution. Waste generation is increased due to the implementation of all these preventive measures. While lockdowns decrease air pollution, unsustainable management of face mask waste and temperature-controlled supply chains of vaccination potentially increases air pollution.

Recent advances on Nickel Nano-ferrite: A review on processing techniques, properties and diverse applications

Abstracts Ferrites belong to the wonder class of materials which are known for their wide application range. Among ferrites, spinel ferrites belong to the most promising soft magnetic materials with excellent properties like engineered band gap, high saturation magnetization, coercivity, and better thermal and electrical properties. Among spinel ferrites, Nickel ferrites: a soft, highly magnetic material that exhibit excellent electrical, magnetic, and optical characteristics. Nickel ferrites find their space in a variety of applications because of their unique properties when compared to other ferrite family members. These properties include high saturation magnetisation, less coercivity, high resistivity and permeability. In addition, nanometric Ni ferrites are unique in several properties with modified applications, such as high frequency applications, electronic devices with low loss, biomedical applications, and environmental remedial applications also. This review aim to explore possible synthesis routes, unique properties and diverse applications of Ni ferrite.