Organic molecule functionalized lead sulfide hybrid system for energy storage and field dependent polarization performances.

A wet chemical route is reported for synthesising organic molecule stabilized lead sulfide nanoparticles. The dielectric capacitance, energy storage performances and field-driven polarization of the organic-inorganic hybrid system are investigated in the form of a device under varying temperature and frequency conditions. The structural analysis confirmed the formation of the monoclinic phase of lead sulfide within the organic network. The band structure of lead sulfide was obtained by density functional theory calculation that supported the semiconductor nature of the material with a direct band gap of 2.27 eV. The dielectric performance of the lead sulfide originated due to the dipolar and the space charge polarization. The energy storage ability of the material was investigated under DC-bias conditions, and the device exhibited the power density values 30 W/g and 340 W/g at 100 Hz and 10 kHz, respectively. The electric field-induced polarization study exhibited a fatigue-free behaviour of the device for 103 cycles with a stable dielectric strength. The study revealed that the lead sulfide-based system has potential in energy storage applications.

Removal of toxic dye from dye-laden wastewater using a new nanocomposite material: Isotherm, kinetics and adsorption mechanism.

In this study, (hemi)cellulosic biochar-based environment-friendly non-toxic nanocomposite (nAg-AC) was fabricated for an inordinate overlook of toxic dye-laden wastewater depollution. This hybrid nanocomposite grafted with silver nanoparticles, numerous hydroxyl and π-bond containing functional groups exhibited outstanding physicochemical properties. FESEM images indicated the heterogeneous porous structure of nAg-AC, while BET analysis revealed mesoporous property with a significant increment of overall surface area (132%). Imbedding of silver nanoparticles and the presence of multiple hydroxyl groups was evident from the XRD and XPS spectrum. Further, the TGA result indicated excellent thermal stability, and FTIR analysis suggested the involvement of surface functional groups like -OH, =C = O, =NH, =C = C = , and -CH in Rhodamine B (RhB) adsorption. The adsorbent matrix provided the overall mechanical strength and facilitated recycling, while the functional matrix (biochar) provided the adsorptive locus for augmented RhB adsorption efficiency (92.77%). Experiments pertaining to adsorption isotherms and kinetics modeling suggested that RhB was removed through multilayer chemisorption on the heterogeneous nAg-AC surface. The main RhB adsorption mechanism included cumulative efforts of H-bindings, π-π stacking interaction, pore-filling, and electrostatic interactions. The nAg-AC maintained mechanical robustness with significant RhB adsorption even after three consecutive regeneration cycles signifying facile recycling. The nAg-AC displayed an outstanding efficacy for the real industrial wastewater depollution, indicating high effectiveness for practical environmental applications. Finally, the cost analysis (incorporating economic, environmental, and social dimensions) suggested a significant role of the nAg-AC in promoting and establishing sustainable development with the circular economy.

Biochar-based nanocomposite from waste tea leaf for toxic dye removal: From facile fabrication to functional fitness.

The present study utilized discarded tea leaf waste to produce 'Tea leaf biochar' (TLB) as the functional matrix for the fabrication of hybrid nanocomposite (nAg-TC), with colloidal deposition of silver nanoparticles (nAg) via modified chemical co-precipitation, for treatment of dye-laden wastewater. The chemical composition, physicochemical properties, and morphology of nAg-TC, and active surface functional groups involved in adsorption were identified using BET, FESEM-EDX, FTIR, TGA, XPS, and XRD. The nAg-TC matrix was found to be heterogeneous, mesoporous, thermostable, with rich in active surface functional groups (-OH, =NH, =CH, CC, CO, CN, and CC), and nAg as a dopant material. The dye adsorption results indicated the maximum removal efficiency (RhB = 95.89%, CR = 94.10%) at 300 K for rhodamine B (RhB) and Congo red (CR) concentrations of 25 mg L-1 and 22.5 mg L-1, respectively. The present investigation agreed with Freundlich isotherm (R2CR:0.991; R2RhB:0.993) and pseudo-second order kinetic (R2CR:0.999; R2RhB:0.999) model, indicating overall adsorption of RhB and CR through spontaneous and exothermic chemisorption on the heterogeneous surface of nAg-TC. The mechanism of RhB and CR adsorption was complex where nAg-TC, possessing the synergistic effects of TLB and nAg, showed surface complexation, electrostatic attraction, and H-bonding, leading to chemisorption. Study showed excellent reusability of spent nAg-TC, and commendable treatment efficiency for dye-laden real industrial effluents. The study exhibits substantial techno-economic feasibility of adsorbent and translates the principles of circular economy into synthesis of value-added products through sustainable management of biowaste and bioresource.

Fabrication of biochar-based hybrid Ag nanocomposite from algal biomass waste for toxic dye-laden wastewater treatment.

Dual functional innovative approaches were developed to tackle the algal scum problem in water by utilizing the algal (Spirogyra sp.) biomass waste for organic dye-laden industrial wastewater treatment, a global problem, and challenge. Therefore, an algal biochar-based nanocomposite (nAgBC) was synthesized and employed as a low-cost adsorbent for Congo red (CR) removal. Surface morphology, physicochemical characteristics, elemental composition, phase, and stability of the nanocomposite was analyzed using BET, FESEM-EDX, FTIR, XRD, XPS, and TGA. The nanocomposite was found to be thermostable, mesoporous with large and heterogeneous surface area, containing nAg as doped material, where -OH, NH, CO, CC, SO, and CH are the surface binding active functional groups. Maximum adsorption efficiency of 95.92% (18 mg L-1 CR) was achieved (qe = 34.53 mg g-1) with 0.5 g L-1 of nanocomposite after 60 min, at room temperature (300 K) at pH 6. Isotherm and kinetic model suggested multilayer chemisorption, where adsorption thermodynamics indicated spontaneous reaction. Fluorescens spectral analysis of CR confirmed the formation of CR supramolecule, supporting enhanced adsorption. Furthermore, the result suggested a 5th cycle reusability and considerable efficacy towards real textile industrial effluents. Synergistic effects of the active surface functional groups of the biochar and nAg, along with the overall surface charge of the composite lead to chemisorption, electrostatic attraction, H-bonding, and surface complexation with CR molecules. Thus, synthesized nAgBC can be applicable to mitigate the wastewater for cleaner production and environment.

A review of the phytochemical mediated synthesis of AgNP (silver nanoparticle): the wonder particle of the past decade.

Silver nanoparticle (AgNP) has been one of the most commonly used nanoparticles since the past decade for a wide range of applications, including environmental, agricultural, and medical fields, due to their unique physicochemical properties and ease of synthesis. Though chemical and physical methods of fabricating AgNPs have been quite popular, they posed various environmental problems. As a result, the bioinspired route of AgNP synthesis emerged as the preferred pathway for synthesis. This review focuses extensively on the biosynthesis of AgNP-mediated through different plant species worldwide in the past 10 years. The most popularly utilized application areas have been highlighted with their in-depth mechanistic approach in this review, along with the discussion on the different phytochemicals playing an important role in the bio-reduction of silver ions. In addition to this, the environmental factors which govern their synthesis and stability have been reviewed. The paper systematically analyses the trend of research on AgNP biosynthesis throughout the world through bibliometric analysis. Apart from this, the feasibility analysis of the plant-mediated synthesis of nanoparticles and their applications have been intrigued considering the perspectives of engineering, economic, and environmental limitations. Thus, the review is not only a comprehensive summary of the achievements and current status of plant-mediated biosynthesis but also provides insight into emerging future research frontier. Supplementary Information: The online version contains supplementary material available at 10.1007/s13204-021-02135-5.

Light effect on Click reaction: Role of photonic quantum dot catalyst.

Due to the light excitation, the valence band electron of the copper (I) sulfide quantum dot transfer to the conduction band and act as a scavenger of the terminal proton of the alkyne in the presence of organic azide with the formation of 1,4-disubstituted 1,2,3-triazoles, where the copper(I) species of Cu2S act as a catalyst for the reaction. The above cycloaddition reaction between alkyne and azide is commonly known as the Click reaction. In this study, experiments were carried out under the exposure of ultra-violate and daylight and also dark environment. According to the original recommendation for the Click reaction, the role of the base was also considered for this experiment. We found that the effect of conduction band electron is more efficient than the recommended conventional base mediated reaction procedure.

Polymer immobilized Cu(I) formation and azide-alkyne cycloaddition: A one pot reaction.

During the polymerization of aniline using copper sulphate, act as an oxidizing agent, the in-situ synthesized Cu(I) ion catalyzed the cyclo-addition between azides and alkynes. This work represents the merging of two steps, synthesis of the catalyst and application of the catalyst, in a one pot reaction. The elimination of the separate catalyst synthesis step is economic in terms of cost and time. As aniline was used as one of the reactant components so there is no requirement to use additional base for this reaction that further eliminates the cost of the process. Again, the catalyst can be readily recovered by filtration and efficiently used for the several sets of reactions without any significant loss of catalytic activity.

Stealth lipoplex decorated with triazole-tethered galactosyl moieties: a strong hepatotropic gene vector.

Mono-antennary galacto derivatives of cholesterol are being actively developed to direct lipoplexes to the asialoglycoprotein receptor (ASGP-R) on hepatocytes. Here we report on a novel ASGP-R ligand cholest-5-en-3-yl [1-(ß-D-galactopyranosyl)-1H-1,2,3-triazol-4-yl]methylcarbamate (4), assembled by a copper(I)-catalyzed azide-alkyne cycloaddition (click chemistry), and compare it with cholest-5-en-3-yl-ß-D-galactopyranoside (2) and cholest-5-en-3-yl [1-(ß-D-galactopyranosyl-1'-oxy)phen-4-yl]carbamate (3), in liposome formulations with or without 5 mol% distearoylphosphatidylethanolamine poly(ethylene glycol)2000, intended for DNA delivery to ASGP-R-positive hepatocyte-derived HepG2 cells and the ASGP-R-negative embryo kidney cell line HEK293. Transfection levels attained with lipoplex 4 were 100 and 300% greater than those for lipoplexes 2 and 3 respectively in HepG2 cells, while competition assays reduced transfection levels by up to 98%. Transfection activities achieved in HEK293 cells were up to three orders of magnitude lower. Therefore, 4 is representative of a new class of promising hepatotropic ligands for gene delivery.

Efficient nucleic acid transduction with lipoplexes containing novel piperazine- and polyamine-conjugated cholesterol derivatives.

To advance the use of cationic lipids for non-viral nucleic acid vector formulation, a panel of novel nitrogen heterocycle cholesteryl derivatives containing a biodegradable carbamate linker was synthesised. Optimally acting piperazine and cyclen compounds had nucleic acid-binding and lipoplex nanoparticle formation properties that were suitable for their use as non-viral vectors. It was found that the lipoplexes formed were capable of efficient non-toxic nucleic acid delivery to cells in culture. The chemical structure of individual cationic lipids, which is likely to influence lipoplex formation, affected efficiency of DNA or RNA transfection. The results indicated that the cyclen containing compound possessing two cholesteryl moieties resulted in efficient siRNA-mediated target gene silencing but was a poor reagent for DNA transfection.