Eco-friendly Route Research Articles

Plant-Derived Tandem Drug/Mesoporous Silicon Microcarrier Structures for Anti-Inflammatory Therapy.

The properties of nanostructured plant-derived porous silicon (pSi) microparticles as potential candidates to increase the bioavailability of plant extracts possessing anti-inflammatory activity are described in this work. pSi drug carriers were fabricated using an eco-friendly route from the silicon accumulator plant bamboo (tabasheer) powder by magnesiothermic reduction of plant-derived silica and loaded with ethanolic extracts of Equisetum arvense, another silicon accumulator plant rich in polyphenolic compounds. The anti-inflammatory properties of the active therapeutics present in this extract were measured by sensitive luciferase reporter assays; this active extract was subsequently loaded and released from the pSi matrix, with a clear inhibition of the activity of the inflammatory signaling protein NF-κB over a period of hours in a sustained manner. Our results showed that after loading the extracts of E. arvense into pSi microparticles derived from tabasheer, enhanced anti-inflammatory activity was observed owing to enhanced solubility of the extract.

Surface Functionalization of Polyester Fibers via One-step Green Formation and Assembling of Iron Oxide Nanoparticles with Photo and Magneto Activities

In this research for the first time, surface functionalization of polyester fibers was performed via one-step, facile and clean strategy through green synthesis and deposition of iron oxide nanoparticles for photocatalytic and magnetic applications. The commercial ash of Seidlitzia Rosmarinus plant was used as a natural alkaline source for nanoparticles synthesis as well as surface modification of polyester substrate and iron sulfate as metal precursor. The presence of iron oxide nanoparticles on polyester fibers was proved by X-ray diffraction analysis, energy-dispersive X-ray spectroscopy, mapping, field-emission scanning electron microscope images and Fourier transform infrared spectra. The fabricated samples exhibited very good photocatalytic activities toward methylene blue decoloration about 95.45% after 48 h exposing to sunlight irradiation. In addition, they indicated appropriate magnetic properties with saturated magnetization of 2.30 and 1.69 emu/g at room temperature. The coloring effect, weight change and wettability behavior of the fabricated samples were also investigated. The mentioned route in this paper can simply be scaled up as an eco-friendly and scalable route for surface functionalization of polymeric substrates via synthesis and deposition of iron oxide nanoparticles to acquire durable photo and magneto activities on polymers for different applications.

ZnO nanoparticles via Sutherlandia frutescens plant extract: physical and biological properties

The quest for eco-friendly synthetic routes for the development of multifunctional nanoparticles for biomedical applications has reinforced the use of plant extracts as replacement solvents. Amongst the various nanoparticles, ZnO nanoparticles have emerged as a preferred candidate for various biological applications. In this study, ZnO nanoparticles were successfully synthesized by the solvothermal method using Sutherlandia frutescens extract. The morphological, structural, functional properties, elemental mapping and mass to charge ratio analysis were confirmed by TEM, SEM, SAED, FTIR, EDS and LCMS techniques. The ZnO nanoparticles exhibited a spherical morphology with a particle size distribution ranging from 5–25 nm. FTIR corroborated the formation of these nanoparticles with the ZnO peak identified in the fingerprint region. FTIR further showed the introduction of the phytochemical functional groups found in plants that were also confirmed on the Sf ZnO nanoparticles. The presence of bioactive molecules extracted from the plants were tested using wet chemistry and identified by LCMS. EDS analysis exhibited strong ZnO peaks which were verified by their elemental mapping using the same technique. Sf ZnO nanoparticles displayed exceptional biomedical activity with an antiproliferative effect of 93% against human lung cancer cells (A549) owing to the phytochemicals obtained from the Sutherlandia frutescens plant extract. These nanoparticles were also potent against gram-negative (Escherichia coli, Pseudomonas aeruginosa) and gram-positive (Staphylococcus aureus, Enterobacter faecalis) strains using model pollutants and real water pollutants.

Highly porous N-doped carbons production from biomass for high-performance supercapacitors without chemical nitrogen-containing dopants

ABSTRACTPorous N-doped carbons were successfully synthesized via a facile and eco-friendly nitrogen-doping route without N-containing chemical dopants, where bean dregs natural N dopant instead of hazardous chemical reagents. Through co-pyrolysis and activation of rice husk and bean dregs at different mass ratios of RH and BD (1:0, 2:1, 1:1, 1:2, 1:0), a series of carbon materials were fabricated. The physicochemical properties and capacitive performance of carbon were investigated. RBAC-3 displayed superior capacitive performance. The capacitance reached 319 F g−1 at 0.2 A g−1 using two-electrode system. The capacitance retention is as high as 92.6% after 10,000 cycles. The corresponding energy density reached 15.3 Wh kg−1, increased by 37% in comparison of pure rice husk-based electrode in 6 M KOH electrolyte. That result was ascribed to the best synergistic effects of hierarchical porous structure and particular nitrogen content, suggesting a promising electrode fabrication for high-performance supercapacitors.

Textile-based RGO-muffled cobalt (II, III) oxide hybrid nano-architectures for flexible energy storage device

Recent century is enduring a passionate development of hardback electronic devices that promised to be more reliable power sources with higher energy density and long-term stability. To push up the energy density limit of solid-state symmetric supercapacitor (SSC) devices here we report RGO-muffled cobalt (II, III) oxide nanowires hybrid nanostructures as a potential aspirant in the field of flexible and portable electronics. The eco-friendly chemical route was followed to synthesize RGO enfolded cobalt (II, III) oxide nanowires on flexible carbon fabric substrate (CONW-RGO), which disclosed prevailing electrochemical performances rather than cobalt (II, III) oxide nanowires on flexible carbon fabric (CONW). The specific capacitance of CONW-RGO electrode we achieved 1110 F/g at current density 1 A/g, measured in 3-electrode configuration. Also solid state symmetric device performances were investigated which provide extensive potential window of 0 to 1.5 V. As-fabricated device dispensed higher energy and power density 34.78 Wh/kg (0.214 mWh/cm3) and 3.6 kW/kg (23 mW/cm3) respectively and exhibited outstanding cyclic performance by retaining 86.4% capacitance after 10,000 cycles. This is the very first time report of using CONW-RGO electrode as binder-free flexible SSC device with moderately widen potential window.

Green chemistry route to realize, high quantum yield carbon quantum dots for cellular imaging applications

Carbon quantum dots (CQDs) with exceptionally high photoluminescence quantum yield (PLQY) of 77% are synthesised in a single step from multiwalled carbon nanotubes (MWCNTs) through eco-friendly synthetic route using a greener solvent, lemon juice and this novel approach is the highlight of the present work. The multiple roles played by the high citric acid content in lemon as oxidizing, stabilizing as well as capping agent are the prime factors effecting the generation of CQDs of high PLQY. Transmission electron microscopy (TEM) images show well seperated spherical CQDs of average size 5 nm and the high-resolution TEM (HRTEM) image reveals that the nanoparticles are highly crystalline with lattice spacing of 0.33 nm, strictly matching with the (002) plane of graphitic carbon. The Fourier transform infrared (FTIR) spectroscopic studies confirm the presence of abundant carboxyl functionalities on the CQDs surfaces. The photoluminescence emission spectra of the CQDs exhibit excitation dependent emission and intensity variations, which are the unique features of the CQDs. Near infra-red (NIR) excited NIR emission and up-conversion photoluminescence (UCPL) emission properties exhibited by these CQDs offer opportunities in many biological applications. Cellular uptake studies using fluorescence imaging and cytotoxicity studies establish the potentials of the CQDs as high performance yet nontoxic fluorescence agents for bio-imaging applications.

Simple fabrication of Pr2Ce2O7 nanostructures via a new and eco-friendly route; a potential electrochemical hydrogen storage material

A facile and eco-friendly route to prepare pure Pr2Ce2O7 nanostructures with very desirable performance in hydrogen storage has been developed utilizing a novel and efficient fuel, banana extract, at mild condition. For the first time, by altering effective factor, calcination temperature, the different morphologies of Pr2Ce2O7 were formed utilizing banana extract. For the first time, the prepared Pr2Ce2O7 with use of banana extract were evaluated for their hydrogen storage efficiency with chronopotentiometry method. After 20 cycles, its discharging capacity can reach to 2611 mAh/g. The prepared Pr2Ce2O7 with use of banana extract illustrates proper efficiency for hydrogen storage at room temperature.

Room temperature phytosynthesis of silver nanoparticles using leaf extract of Momordica charantia: optical and antimicrobial properties

Nigeria is endowed with rich diversity of medicinal plants whose potential as “green” reducing agents are under-utilized. As the world is advocating for safe environment, plant-mediated synthesis of nanoparticles is considered as an eco-friendly and sustainable synthetic route instead of using toxic chemicals. The method is fast, easy and cheaper compared with other conventional techniques. In this study, phytochemicals present in the leaf extract of indigenous Momordica charantia served as reducing, capping/stabilizing agents. The synthesized silver na-noparticles were characterized with Uv-vis spectrophotometer, photoluminescence (PL) and energy-dispersive x-ray spectrometer (EDX). Antimicrobial activities of the synthesized nanosilver were investigated on isolated Streptococcus pyogenes, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa Candida albicans and Trichophyton rubrum. Optical measurement showed surface plasmon resonance with broad absorption peaks (400-450 nm). Significant growth inhibitions were also found at P <0.05 by means of analysis of variance SPSS tool. The leaf influenced nanosilver displayed highest activity on S. aureus, S. pyogenes and E. coli with MIC and MBC value of 12.5 mg/mL. Least activity was detected against P. aeruginosa (50 mg/mL MIC and 100 mg/mL MBC). From this work, the biogenic nature and optical properties displayed by the as-prepared nanosilver strongly suggest its applications as candidate for therapeutic drugs, diagnostic and medical imaging.

Graphene nanoclusters embedded nickel cobaltite nanofibers as multifunctional electrocatalyst for glucose sensing and water-splitting applications

Nickel cobaltite (NCO) attains the apex of Sabatier-type volcano plot for electrochemical reaction compared to simple oxides due to synergetic effect of mixed transition metal cations. The combination of high surface area, aspect ratio, and porosity of electrospun NCO nanofibers (NCO-NF) enhance their electrocatalytic performance by improved electron mobility and more active sites. In the present study, NCO-NF fabricated using poly (styrene-co-acrylonitrile) (SAN) as a sacrificial polymer, were embellished with graphene nanoclusters (GNC), which augment the electrocatalytic performance of the NCO-NF. The in situ formed GNC along the NCO-NF are result of the interaction between the polar functional groups of the polymer, and the cations of precursor salts during the calcination of precursor nanofibers. The GNC/NCO-NF with least crystallite size and high aspect ratio having porous NCO nanoparticles and in situ grown GNC were developed using sol-gel electrospinning process assisted by calcination of precursor nanofibers. This simple, eco-friendly, and economical synthesis route with unique structure chemistry of SAN to form GNC and the presence of dual cations (Ni and Co) provides enhanced performance and multifunctionality to GNC/NCO-NF electrodes for electrocatalytic applications, such as biosensors and water-splitting. In the present study, the modified electrodes (GNC/NCO-NF/graphite electrode) exhibited excellent non-enzymatic glucose detection over a wide range of concentration with a lower limit of 1.2 μM and sensitivity of 1827.5 μA mM−1 mg−1 in 0.1 M NaOH. Further, the modified electrodes were also tuned for H2O2 detection to aid enzymatic glucose sensing. When examined for bifunctional water-splitting in 1 M NaOH, the electrode reached an onset potential of −0.537 V and 0.735 V against reversible hydrogen reference electrode and a Tafel slope of 37.6 mV·dec−1 and 67.0 mV·dec−1 for hydrogen and oxygen evolution reactions, respectively. The results prove that GNC/NCO-NF are promising candidates as multifunctional electrocatalyst.

Oxidative desulfurization of model and real oil samples using Mo supported on hierarchical alumina–silica: Process optimization by Box–Behnken experimental design

Abstract The catalytic performance of Mo supported on hierarchical alumina–silica (Si/Al = 15) with Mo loadings of 3, 6 and 15 wt% was investigated for the oxidative desulfurization (ODS) of model and real oil samples. Hierarchical alumina–silica (hAl–Si) was synthesized by economical and ecofriendly silicate-1 seed-induced route using cetyltrimethylammonium bromide (CTAB) as mesoporogen. The effect of CTAB on the structure of catalyst was studied by characterization techniques. The results revealed that 6%Mo/hAl–Si had the highest sulfur removal compared to the other catalyst loadings. The effect of operating parameters was evaluated using Box–Behnken experimental design. The optimal desulfurization conditions with the 6%Mo/hAl–Si catalyst were determined at oxidation temperature of 67 °C, oxidation time of 42 min, H2O2/S molar ratio of 8 and catalyst dosage of 0.008 g·ml−1 for achieving a conversion of 95%. Under optimal conditions, different sulfur-containing compounds with initial concentration of 1000 ppm, Dibenzothiophene (DBT), Benzothiophene (BT) and Thiophen (Th), showed the catalytic oxidation reactivity in the order of DBT > BT > Th. According to the regeneration experiments, the 6%Mo/hAl–Si catalyst was reused 4 times with a little reduction in the performance. Also, the total sulfur content of gasoline and diesel after ODS process reached 156.6 and 4592.2 ppm, respectively.

Hetero-nanostructured metal oxide-based hybrid photocatalysts for enhanced photoelectrochemical water splitting – A review

This review is mainly focused on nanostructured metal oxide-based efficient photocatalysts for photoelectrochemical (PEC) water splitting applications. Owing to their distinctive physical and chemical properties, metal-oxide nanostructures have attracted a wide research interest for solar power-stimulated water splitting applications. Hydrogen generation by solar energy-assisted water splitting is a clean and eco-friendly route that can solve the energy crisis and play a significant role in efforts to save the environment. In this review, synthesis strategies, control of morphology, band-gap properties, and photocatalytic application of solar water splitting using hierarchical hetero-nanostructured metal oxide-based photocatalysts, such as titanium dioxide (TiO2), zinc oxide (ZnO), and tungsten/wolfram trioxide (WO3), are discussed.

Eco-Friendly Method for Tailoring Biocompatible and Antimicrobial Surfaces of Poly-L-Lactic Acid.

In this study, a facile, eco-friendly route, in two steps, for obtaining of poly-L-lactic acid/chitosan-silver nanoparticles scaffolds under quiescent conditions was presented. The method consists of plasma treatment and then wet chemical treatment of poly-L-lactic acid (PLLA) films in a chitosan based-silver nanoparticles solution (Cs/AgNp). The changes of the physical and chemical surface proprieties were studied using scanning electron microscopy (SEM), small angle X-Ray scattering (SAXS), Fourier transform infrared spectroscopy (FTIR) and profilometry methods. A certain combination of plasma treatment and chitosan-based silver nanoparticles solution increased the biocompatibility of PLLA films in combination with cell line seeding as well as the antimicrobial activity for gram-positive and gram-negative bacteria. The sample that demonstrated from Energy Dispersive Spectroscopy (EDAX) to have the highest amount of nitrogen and the smallest amount of Ag, proved to have the highest value for cell viability, demonstrating better biocompatibility and very good antimicrobial proprieties.

Eco-friendly route for dyeing of cotton fabric using three organic mordants in reactive dyes

The textile dyes and fixing agents that used in dyeing process are major contributor to environmental pollution. In the present study, three different organic mordants (Sodium Citrate, Ammonium Acetate, and Potassium Acetate) are used in exhaust dyeing as mordants. Effect of mordant concentrations is studied on fastness properties (color change, rubbing fastness &amp; light fastness) of cotton dyed with reactive dyes using these organic mordants. Comparison of these mordants with conventional fixing agent (NaCl) is also studied in order to evaluate the difference between fastness properties of conventional and organic salts used in this study. We found that the color fastness properties of conventional and organic salts are comparable, better in case of sodium citrate. Similarly color depth on fabric after dyeing with organic as well as inorganic salts is measured using data color. Results confirm that higher values of K/S are obtained for organic salts by using lower organic salt concentration compared to conventional salt. Reduction in total dissolved solids (TDS) of dye effluents is obtained from 6% to 29% for three organic salts as compared to conventional salt.

Temperature-sensitive luminescence of Y2O3:Nd3+ nanocrystals produced by an eco-friendly route

The present paper describes the production via a new modified sol-gel route and the characterization of yttrium oxide nanoparticles doped with neodymium ions (Y2O3:Nd3+) aiming applications in temperature sensing of biological systems. The proposed synthesis route uses the chelating capability of natural humic substances present in river water to polymerize the departing metal solution, leading to well-crystalline nanoparticles after calcination at 450 °C. The produced samples were characterized by means of differential thermal analysis and thermogravimetry (DTA/TG), X-ray diffraction (XRD), Fourier-transformed infrared spectroscopy (FTIR), optical absorption (OA) and temperature-dependent luminescence. The high values of relative sensitivity (Sr) of the produced Nd-doped Y2O3 nanocrystals indicates the potentialities of these materials for temperature sensing in nanoscale.

Carbon-incorporated, nitrogen-doped branch-like TiO2 nanostructure towards superior lithium storage performance

Hierarchical TiO2 nanostructures have shown a good prospect for energy storage and conversion. However, the intrinsic low conductivity and sluggish reaction kinetics greatly hamper their applications as the anode materials for lithium-ion batteries (LIBs). Herein, an eco-friendly route has been developed as a scalable strategy for preparing the anatase TiO2 nanostructures via a simple template-free hydrothermal process. The as-made TiO2 product has a high surface area of 146.3 m2 g−1 and a unique hierarchically branched nanostructure, which is constructed by the rigid trunk and flexible nanosheets. Significantly, the product demonstrates the uniform distribution of carbon/nitrogen in the TiO2 architecture. Benefiting from these unique structural features, the TiO2-400 electrode shows a superior electrochemical performance for reversible lithium storage, demonstrating a high reversible capacity of 268.2 mA h g−1 at 100 mA g−1 after 600 cycles and long cycling life. This study also opens a new window for rational design of hierarchical nanostructures with excellent properties by an environmentally benign technique.

Synthesis and biological evaluation of pyrazole linked benzothiazole-β-naphthol derivatives as topoisomerase I inhibitors with DNA binding ability.

A series of new pyrazole linked benzothiazole-β-naphthol derivatives were designed and synthesized using a simple, efficient and ecofriendly route under catalyst-free conditions in good to excellent yields. These derivatives were evaluated for their cytotoxicity on selected human cancer cell lines. Among those, the derivatives 4j, 4k and 4l exhibited considerable cytotoxicity with IC50 values ranging between 4.63 and 5.54 µM against human cervical cancer cells (HeLa). Structure activity relationship was elucidated by varying different substituents on benzothiazoles and pyrazoles. Further, flow cytometric analysis revealed that these derivatives induced cell cycle arrest in G2/M phase and spectroscopic studies such as UV-visible, fluorescence and circular dichroism studies showed that these derivatives exhibited good DNA binding affinity. Additionally, these derivatives can effectively inhibit the topoisomerase I activity. Viscosity studies and molecular docking studies demonstrated that the derivatives bind with the minor groove of the DNA.

Computational Modeling of Biosynthesized Gold Nanoparticles in Black Camellia sinensis Leaf Extract

In this research, gold nanoparticles (Au-NPs) are biosynthesized from tetrachloroaurate (AuCl4−) aqueous solution through a simple and ecofriendly route using water extract of black Camellia sinensis leaf (C. sinensis L.) which acted as a reductant and stabilizer simultaneously. The prepared gold nanoparticles are characterized using UV-visible spectroscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM). Also, determination of the accurate predictor model for chemical reactions is particularly important because of high cost of the chemical materials and measurement devices. While the artificial neural networks (ANNs) are one of the appropriate tools to forecast any phenomena, due to the low number of data set related to chemical experimental was caused to provide appropriate model is a time-consuming iterative process. With the aim to improve the accuracy of the ANN model and overcome the local convergence of this problem, a global search technique, biogeography-based optimization (BBO) method which integrated by chaotic map is employed. The improved model showed minimum mean squared error (MSE) of 0.0134 and maximum coefficient of determination (R2) equal to 0.9822 compared with several other famous ANN training algorithm, utilizing output experimental data obtained from biosynthesis proceeding.

A novel pseudo six-component synthesis of functionalized pyrazoles in ethanol by cascade reaction

Novel-substituted pyrazoles were synthesized using an aminal-based approach. The key steps in the synthetic strategy involve the formation of 1,1-dihydrazino-2-nitroethylene from hydrazine hydrate with nitro ketene dithioacetal and its reaction with Knoevenagel adduct derived from the corresponding aldehyde and malononitrile in ethanol media. The formation of 5-membered pyrazole ring is confirmed based on the electrostatic surface potential computed by density functional theory. This strategy can provide a concise and eco-friendly route for easy access to the highly substituted pyrazoles derivatives in excellent yields using four simple and readily available building blocks under mild conditions and particularly attractive due to features such as atom economy, high yield and mild condition.

A green and facile synthesis for rGO/Ag nanocomposites using one-step chemical co-reduction route at ambient temperature and combined first principles theoretical analyze

Recently, graphene decorated with various inorganic nanoparticles, such as Pt, Au, Ag, TiO2 and Fe3O4, among which Ag nanocomposites are good candidates for electronics, optics, electrochemistry and catalysis. However, preparation techniques for Ag nanoparticles/carbon matrix hybrids require tedious multi-step processes often involving toxic reducing agents/high temperatures which is not viable for scalable production. Here, a facile, one step and eco-friendly chemical co-reduction route was utilized to synthesis of a new nanocomposites by Ag nanoparticle anchored on reduced graphene oxide (rGO) at ambient temperature and combined first principles theoretical analyze their interfacial adsorption behavior, is reported. In this way, graphene oxide (GO) and Ag+ simultaneously reduced by thiourea dioxide (TD) without using any additional reduced reactants. Results indicated that GO was successfully reduced to rGO and well-dispersed Ag nanoparticles with sizes of 6–7 nm, anchored on the surface of rGO sheets. Reduction mechanism was attributed to the synergistic effect of its hydrolysis products in aqueous media. The experiment and theoretical calculation results obtained demonstrate this method to be applicable to the synthesis of other metals on rGO sheets in order to improve wettability and interfacial bonding between rGO and metal and may possibly find various forthcoming medicinal, industrial and technological applications.

An eco-friendly route for template-free synthesis of high specific surface area mesoporous CeO2 powders and their adsorption for acid orange 7.

An eco-friendly route was developed for the synthesis of mesoporous CeO2 powders without any additional template. The original cerium precursors were separated from Ce3+ aqueous solution by (NH4)2CO3 or Na2CO3via a chemical precipitation method, then H2O2 was introduced to induce the phase transformation from original cerium precursors to CeO2 precursors with initial porous structures, finally the crystallinities of CeO2 precursors were improved by a hydrothermal treatment, meanwhile the mesoporous structures of final CeO2 powders were formed. The BET surface areas of mesoporous CeO2 powders synthesized using (NH4)2CO3 and Na2CO3 as precipitants were 106.1 and 76.9 m2 g−1, respectively. Moreover, a mesoporous CeO2 sample with BET surface area of 100.0 m2 g−1 was also synthesized using commercial Ce2(CO3)3·xH2O as an existing cerium precursor under the same conditions as control, which could shorten experimental processes and reduce costs. The oxidation-induced phase transformation from original cerium precursors to CeO2 precursors with initial porous structures was the precondition for further forming of mesoporous structures of final CeO2 powders during the hydrothermal process. These mesoporous CeO2 powders showed the rapid and effective adsorption for acid orange 7 dye from simulated wastewater without pH pre-adjustment at room temperature. Furthermore, the adsorption capacities of these mesoporous CeO2 powders for removal of acid orange 7 dye were determined according to the Langmuir linear fits.