It has been shown that in the last decades nanotechnology plays a key role not only in science but more and more often in industry as well. Recent research has shown that agricultural waste is a possible feedstock to produce nanocellulose which can be used for different applications, such as a biosensor, semiconductor and reinforcing agent. The use of agro-waste as a precursor not only offers advantages for raw material costs, but also for the climate, low processing costs, availability and convenience. It also helps to address environmental issues, such as illness, foul odor and concerns with indoor use. Different processes, such as chemical treatment, mechanical treatment and chemo-mechanical treatment, have been used to extract nanocellulose from agro-waste. This article highlights the latest technologies used to acquire agro-waste nanocellulose, as well as existing advances in and applications of nanocellulose technologies.

Passive cooling techniques have been used mostly in countries with hot and arid climates such as Iran, Egypt, and India. However, the use of this important technology has not been seriously considered until a time of energy crisis, and consequently, environmental crisis scenarios, emerge. Scholars have renewed their interest in investigating passive cooling technology, particularly the aspects of new materials, thermal comfort, energy efficiency, new designs, climate, and environmental considerations. This review paper highlights the opportunities to use green materials, such as geopolymers, as evaporative cooling materials with different types of industrial and agricultural waste products as components. Novel ideas for passive cooling design using ancient and nature-inspired concepts are also presented to promote green technology for future applications.