Citrous Lime-A Functional Reductive Booster for Oil-Mediated Green Synthesis of Bioactive Silver Nanospheres for Healthcare Clothing Applications and Their Eco-Mapping with SDGs.

Silver nanoparticles (Ag-NPs) are most effective against pathogens and have widely been studied as antibacterial agents in commodity clothing, medical textile, and other hygiene products. However, prolonged utilization of silver and rapid mutation in bacterium stains has made them resistant to conventional silver agents. On the other hand, strict compliance against excessive utilization of toxic reagents and the current sustainability drive is forcing material synthesis toward green routes with extended functionality. In this study, we proposed an unprecedented chemical-free green synthesis of bioactive Ag-NPs without the incorporation of any chemicals. Cinnamon essential oil (ECO) was used as a bio-reducing agent with and without the mediation of lime extract. A rapid reaction completion with better shape and size control was observed in the vicinity of lime extract when incorporated into the reaction medium. The interaction of natural metabolites and citrus compounds with nanoparticles was established using Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. The application of as-prepared nanoparticles on textiles encompasses extended bioactivity to treated fabric with infused easy-care performance. To the best of our knowledge, this is the first reported instance of utilizing bioactive silver nanoparticles as a functional finish, both as an antimicrobial and as for easy care in the absolute absence of toxic chemicals. The easy-care performance of fabric treated with lime-mediated nanoparticles was found to be 141O, which is around 26% better than bare cotton without any significant loss in fabric strength. Furthermore, to enlighten the sustainability of the process, the development traits were mapped with the United Nations Sustainable Development Goals (SDGs), which show significant influence on SDGs 3, 8, 9, and 14. With the effective suspension of microorganisms, added functionality, and eco-mapping with SDGs with the chemical-free synthesis of nanoparticles, widespread utilization can be found in various healthcare and hygiene products along with the fulfillment of sustainability needs.

Elimination of basic blue 9 by electrocoagulation coupled with pelletized natural dead leaves (Sapindus mukorossi) biosorption.

Elimination of basic blue 9 (BB-9), a cationic textile dye, by electrocoagulation coupled with biosorption exploiting pelletized natural dead leaves (PNDL) of Sapindus mukorossi, an economic alternative biosorbent, was investigated. The experimental runs were conducted in a laboratory-scale hybrid reactor loaded with Al electrodes, aeration spargers and PNDL packed twin suspended buckets. The pelletized adsorbents offer key advantages of good mechanical stability, lesser clogging risk, and easy disengagement as compared to powdered adsorbents. The parameters of current density, pH, PNDL dose, and initial dye concentration were studied for the decolorization and COD removal efficiency. The experimental results revealed that up to 99.9% decolorization and 90.01% COD removal efficiency achieved after 8 min at optimum condition of current density (j)=20.27 mA/cm2, pH = 9, PNDL dose = 6 g/L, and initial dye concentration = 50 mg/L. The BB-9 elimination followed the first-order kinetics with K1=0.318 min-1 and R2=0.997. The results revealed the potential of PNDL as a feasible biosorbent with the effective performance of the coupled process.

A study on the influence of pH changes during catalytic ozonation process on alumina, zeolites and activated carbons for the decolorization of Reactive Red-241.

The current study focuses on a prime effect of pH changes in the catalytic ozonation process (COP) by using three main classes of catalysts such as zeolites (alumina-silicates), alumina (metal oxides), and activated carbons for decolorization of Reactive Red 241 (RR-241). The role of pH changes, point of zero charges and the effect of catalyst dose on pH change was studied. The results reveal that the overall removal efficiency of RR-241 in the case of COPs was the highest compared with single ozonation process (at pH = 7 the efficiency was 80, 65 65.5 and 60% for AC/O3, Al2O3/O3, Zeolite/O3 and O3 respectively). At initial acidic pH 4, the highest pH variations in COPs and ozonation processes were observed. Moreover, the pH changes were not found to be significant near the point of zero charges of materials (pHpzc = 6.8, 8.4 and 8.8 for zeolite, activated carbons and Al2O3, respectively. The COP in the presence of activated carbon shows the highest removal efficiency (82%) at pH 7. The material dose effect indicates that increasing the amount of catalyst (from 1 gm to 2 gm) significantly leads to a change in the pH of the solution. Results reveal the prominent effect and significance of pH changes on the efficiency of COP to determine true catalytic efficiency.

A comprehensive review of the current progresses and material advances in perovskite solar cells.

Recently, perovskite solar cells (PSCs) have attracted ample consideration from the photovoltaic community owing to their continually-increasing power conversion efficiency (PCE), viable solution-processed methods, and inexpensive materials ingredients. Over the past few years, the performance of perovskite-based devices has exceeded 25% due to superior perovskite films achieved using low-temperature synthesis procedures along with evolving appropriate interface and electrode-materials. The current review provides comprehensive knowledge to enhance the performance and materials advances for perovskite solar cells. The latest progress in terms of perovskite crystal structure, device construction, fabrication procedures, and challenges are thoroughly discussed. Also discussed are the different layers such as ETLs and buffer-layers employed in perovskite solar-cells, seeing their transmittance, carrier mobility, and band gap potentials in commercialization. Generally, this review delivers a critical assessment of the improvements, prospects, and trials of PSCs.

Novel 3D hierarchically structured cauliflower-shaped SnO2 nanospheres as effective photoelectrodes in hybrid photovoltaics.

Optical and electrical characteristics of wide bandgap metal oxides, namely the charge mobility, bandgap and energy level, directly define the performance and stability of photovoltaics. For the first time, novel three-dimensional (3D) hierarchically structured cauliflower-shaped SnO2 nanospheres with nanorods on their surface were obtained by a simple hydrothermal method without any additives at low temperature. The obtained hierarchically structured SnO2 nanospheres show large specific surface areas, proven to be efficient for sensitizer loading in both perovskite solar cells (PSCs) and dye-sensitized solar cells (DSSCs). The nanospheres could improve light harvesting and also enhance electron transport through the grain boundaries. Ultimately, a maximum power conversion efficiency of 10.37% is obtained for 3D hierarchically structured SnO2 nanosphere-based DSSCs in which SnO2 is used as the scattering layer, and a remarkable efficiency of 20.01% is achieved when 3D hierarchically structured SnO2 nanospheres are employed as the electron transport material in PSCs. We trust that our work provides a new insight into construction and structural design of highly efficient hybrid photovoltaics.

Electrosprayed Polymer-Hybridized Multidoped ZnO Mesoscopic Nanocrystals Yield Highly Efficient and Stable Perovskite Solar Cells.

Solid-state perovskite solar cells have been expeditiously developed since the past few years. However, there are a number of open questions and issues related to the perovskite devices, such as their long-term ambient stability and hysteresis in current density-voltage curves. We developed highly efficient and hysteresis-less perovskite devices by changing the frequently used TiO2 mesoscopic layer with polymer-hybridized multidoped ZnO nanocrystals in a common n-i-p structure for the first time. The gradual adjustment of ZnO conduction band position using single- and multidopant atoms will likely enhance the power conversion efficiency (PCE) from 8.26 to 13.54%, with PCEmax = 15.09%. The highest PCEavg of 13.54% was demonstrated by 2 atom % boron and 6 atom % fluorine co-doped (B, F:ZnO) nanolayers (using optimized film thickness of 160 nm) owing to their highest conductivity, carrier concentration, optical transmittance, and band-gap energy compared to other doped films. We also successfully apply a fine polyethylenimine thin layer on the doped ZnO nanolayers, causing the reduction in work function and overall demonstrating the enhancement in PCE from ∼10.86% up to 16.20%. A polymer-mixed electron-transporting layer demonstrates the remarkable PCEmax of 20.74% by decreasing the trap sites in the oxide layer that probably reduces the chances of carrier interfacial recombination originated from traps and thus improves the device performance. Particularly, we produce these electron-rich multidoped ZnO nanolayers via electrospray technique, which is highly suitable for the future development of perovskite solar cells.