The Coronavirus disease 2019 (COVID-19) global outbreak and its continued growth and mutation into various forms emphasize the need for effective disinfectants to assist in the reduction of the virus’s spread from individual to individuals and community to communities through various modes, including coughing, sneezing, touching of contaminated surfaces, and being in proximity of an unprotected infected person, to mention a few. The rapid development of reliable disinfecting materials or solutions and their incorporation in personal protective equipment is a critical need at the moment that will assist significantly in curbing the spread of the virus SARS-CoV-2, the cause of COVID-19 illness. Here, we present an in situ assembly of antiviral metal nanoparticles on a rigid surface and on commercial face masks made up of nonwoven and woven textiles. The results indicate a very high efficacy of 99.99% against a surrogate virus to SARS-CoV-2. Such a versatile and cost-effective approach using the blade-coating technique can be easily extended to the roll-to-roll manufacturing setting to expedite the efforts and mitigate the rapid spread of the virus.

The COVID-19 pandemic has demonstrated the need for versatile and robust countermeasures against viral threats. A wide range of viruses, including SARS-CoV-2, the virus that causes COVID-19, can be deactivated by metal and metal-oxide surface coatings. However, such coatings are expensive and cannot easily be retrofitted to existing infrastructure. Low-cost materials to halt the propagation of a variety of viruses must be produced with minimal quantities of expensive precursors. In this regard, we show that commercially available copper oxide nanoparticle suspensions can deactivate more than 99.55% of the human coronavirus 229E in 30 min, confirming the particles’ efficiency as a fast antiviral material.

Undoped and Nb-doped TiO 2 nanocrystals are prepared by a microwave-assisted non-aqueous sol–gel method based on a slow alkyl chloride elimination reaction between metal chlorides and benzyl alcohol. Sub-4 nm nanoparticles are grown under microwave irradiation at 80 °C in only 3 h with precise control of growth parameters and yield. The obtained nanocrystals could be conveniently used to cast compact TiO 2 or Nb-doped TiO 2 electron transport layers for application in formamidinium lead iodide-based photovoltaic devices. Niobium doping is found to improve the cell performance by increasing the conductivity and mobility of the electron transport layer. At the same time, a measurable decrease in parasitic light absorption in the low wavelength portion of the spectrum was observed.

The use of sustainable materials in high-tech devices is one way to decrease the carbon footprint and tackle global climate change. We first synthesized blue-emissive carbon dots from biocompatible onion inner epidermal cells using Solvothermal method. Then, cellulose nanofiber was prepared by TEMPO oxidization, followed by homogenisation from soft wood source. Finally, the blue emissive carbon dots-cellulose nanofibers-based nanopaper was fabricated by simple roller-coating approach, and its optical and morphological properties were investigated by Transmittance, PL, FTIR and SEM techniques. The results indicate that nanopapers have a high light emission, and that their transparency may be easily adjusted by varying the proportion of carbon dots content. These nanopapers can be incorporated into flexible and stretchable electronics and optical sensor platforms.

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