Green nanotechnology is the biosynthesis of nanomaterials using natural bioactive agents such as plant materials, microbes, and various biowastes like agricultural residues, eggshells, vegetable waste, fruit peels, etc., and then employing nano-products to enhance sustainability. It is a cost-effective, easy, safe, low-risk, non-toxic, and eco-friendly technique. Green nanotechnology is an important part of clean technologies that aim at environmental remediation and the conversion of extra bioactive products to green nanomaterials, which are more valuable and eco-friendly. Growth in the population is accompanied by an increase in human biowaste, which poses a substantial threat to environmental cleanliness. As a result, it has become important to seek a practical way to solve this problem, which imposes a significant environmental cost.

From this perspective, many researchers have recently been considering ways to benefit from these biowastes by recycling them into acceptable and eco-friendly products. The utilization of recyclable biowastes in the synthesis of nanomaterials is one of these ways, which is known as green nanotechnology. There is no need for high pressure, energy, temperature, or hazardous compounds. It is a biosafe and low-cost approach to the fabrication of nanomaterials for usage in a variety of fields, including catalysis, solar cells, medical pharmaceuticals, industrial fields, sensors, water desalination, water purification, and air purification. Although the topic of green nanotechnology is a fascinating and broad field of research, it can be considered in its early stages. More studies are needed in order to examine the nanoparticles' qualities. Many plants, biowaste products, and microbes have yet to be researched.

This Special Issue focuses on nanoparticles in the fields of green nanotechnology and biotechnology. We welcome original research and review articles dealing with the synthesis, characterization, and applications of these nanoparticles.

Potential topics include but are not limited to the following:

• Green synthesis of metal and metal oxide nanoparticles
• Green synthesis of polymers
• Biosynthesis of nanoparticles
• Applications of green nanoparticles
• Biocompatibility of green nanoparticles
• Remediation of environmental pollutants
• Recycling of biowastes
• Sustainability and natural resources
• Green synthesis of organic nanomaterials
• Treatment of biological pollutants