Green Synthetic Route Research Articles

New phenanthridine-based multi-functional chemosensor for selective detection of Th4+ and Hg2+ ions in both aqueous and solid state

A new phenanthridine-based multifunctional chemosensor (L), was synthesised via a green synthetic route and characterised using FT-IR, NMR and HRMS analysis. The sensing application of L towards metal ions in both solution and solid-state was studied using UV–vis and fluorescence spectroscopy, which exhibits dual-sensing behaviour for Th4+ and Hg2+ ions with good recyclability. In aqueous acetonitrile, L showed rapid response for the detection of environmental toxic metal ions and has a very low analytical detection limit of 125.5 pM and 1.94 nM for Th4+ and Hg2+ions respectively, which is remarkably lower than the World Health Organization standard. The cation binding property of the L with Th4+ and Hg2+ions was investigated by Job plot, 1H NMR titration, HR-MS and DFT calculation. The in-situ formed ensemble L-Hg2+ was further applied in the naked-eye detection of Cys (Cystine) and His (Histidine) over other common amino acids. The utility of L for real-time detection of Hg2+ and Th4+ ions was explored in various sources of environmental water samples, test paper strips, fingerprint imaging, fluorescent ink and smartphone-assisted sensing techniques, demonstrating the promising on-site visualization of the probe in controlling the toxicity levels in wastewater sources without resorting to expensive instruments.

Hierarchically N-doped porous carbon synthesized from 3D cellulose alcogel decorated by in-situ growth of ZIF-8 for high performance CO2 capture

The physical properties and chemical compositions of porous carbons are crucial factors in determining their effectiveness in adsorbing CO2. Cellulose-based porous carbon has emerged as an outstanding candidate adsorbent for CO2 capture. The research involved the creation of hierarchically nitrogen-doped porous carbon (HNC) using a 3D cellulose alcogel (CA) as substrate, which was prepared through a thermal introduced phase separation (TIPS) method combined with hydrolysis treatment. The plentiful functional groups of CA offered abundant growth sites for the introduction of ZIF-8 crystals. CA/ZIF-8 composite alcogel (CZA) with greater surface area and superior thermal stability compared to CA was successfully fabricated and used as precursor for the production of HNC. The important effects of microporosity and surface chemistry of HNC samples on CO2 capture were discussed in-depth. HNC-350–850 displayed a hierarchically porous structure with a large number of micropores and abundant N/O/Zn-doped functional groups, exhibiting high CO2 uptakes at 1 bar (3.56 mmol/g at 25 °C), good IAST CO2/N2 (15/85, V/V) selectivity of 16.31 at 25 °C, and outstanding regenerability with ∼100 % CO2 adsorption capacity retained after ten cycles. In the two-component CO2/N2 (15/85, V/V) competitive adsorption process, the maximum breakthrough periods for CO2 (433.1 s) is significantly longer than that of N2 (3.8 s). The CO2 breakthrough adsorption capacity reached 1.79 mmol/g at 25 °C and 1 bar with the separation coefficient of 45.8 for CO2 over N2. These results confirmed that HNC, in addition to having excellent CO2/N2 selectivity, demonstrated good feasibility for practical use. The green and practicable synthetic route described in this study is not only expected to offer novel adsorbents for high performance CO2 capture, but also provide a new theoretical foundation for the development of cellulose-based porous materials.

Green synthesis of sacrificial UV-sensitive core and biobased shell for obtaining optically hollow nanoparticles

Hollow nanoparticles have been extensively studied in recent years. Obtaining such structures with biobased materials, following greener synthetic routes, is still challenging, especially if accurate particle dimensions are required. This work reports the use of an innovative hybrid silica core (Si@azo) containing UV-sensitive molecule, wrapped in biobased multilayer shell composed of polysaccharides. It is a promising strategy for obtaining optically hollow nanoparticles. Indeed, Si@azo cores have the ability to be partially degraded when irradiated with UV light. Combined with a well-controlled and monodisperse diameter, they provide a good basis for layer-by-layer assembly, leading to a multilayer shell with controlled composition and thickness. Finally, UV irradiation of such a core–shell structure is harmless to the polysaccharide shell, but does impact the hybrid silica core, as revealed by turbidity measurements, among other. Each step, i.e. core synthesis, shell addition, and core–shell irradiation, has been carefully characterized at the macro (Fourier-transform infrared spectroscopy – FTIR, Dynamic Light Scattering – DLS, Zeta-potential measurement, Surface Plasmon Resonance – SPR, turbidity) and microscale (Transmission and Scanning Electron Microscopies). Emphasis is put on how turbidity measurements can be related to the core refractive index (ncore), giving information on the state of core degradation and whether the core–shell particle is optically hollow.

Experimental and Quantum Chemical Studies of a Green Corrosion Inhibitor for Mild Steel in Acidic Chloride Solution

AbstractA green corrosion inhibitor was prepared from the bio‐based platform compound 5‐hydroxymethylfurfural through a green synthetic route, which avoid the use of toxic reagent. The inhibition performance and mechanism of this compound for the corrosion of mild steel in 0.1 M HCl was investigated by using the weight loss experiments, polarization measurements, EIS measurements and quantum chemical calculations. The corrosion inhibition efficiency by weight loss measurement (ηWLM%) of this inhibitor can reach up to 90.3 % at 303 K with 1.2 mM concentration. Moreover, the electrochemical experiments revealed that this corrosion inhibitor acts as a mixed‐type inhibitor. Thermodynamic studies gave the values of the standard Gibbs free energy , fall within the range of −20 kJ/mol to −40 kJ/mol, suggested the adsorption of this compound is a spontaneous process involving both physisorption and chemisorption. In addition, quantum chemical calculations were conducted to further validate the formation of an effective absorption layer by this inhibitor on metal surfaces, which showed that the electron density iso‐surfaces of HOMO was mainly distributed on chloride ions, while LUMO tended to be distributed on furan rings and aldehyde groups. Besides, the other quantum chemical parameters of this inhibitor were also calculated to explore the molecular activity, such as, the molecular volume (ν, 333.105 Å), global hardness (η, 4.706 eV), global softness (σ, 0.2125 eV), electronegativity (χ, 4.93 eV), dipolemoment (μ, 13.1429 D) and vertical ionization energy (VIE, 7.2646 eV).

Highly efficient synthesis of isoxazolones and pyrazolones using g-C3N4·OH nanocomposite with their in silico molecular docking, pharmacokinetics and simulation studies

An environmentally friendly, versatile multicomponent reaction for synthesizing isoxazol-5-one and pyrazol-3-one derivatives has been developed, utilizing a freshly prepared g-C3N4·OH nanocomposite as a highly efficient catalyst at room temperature in aqueous environment. This innovative approach yielded all the desired products with exceptionally high yields and concise reaction durations. The catalyst was well characterized by FT-IR, XRD, SEM, EDAX, and TGA/DTA studies. Notably, the catalyst demonstrated outstanding recyclability, maintaining its catalytic efficacy over six consecutive cycles without any loss. The sustainability of this methodology was assessed through various eco-friendly parameters, including E-factor and eco-score, confirming its viability as a green synthetic route in organic chemistry. Additionally, the gram-scale synthesis verifies its potential for industrial applications. The ten synthesized compounds were also analyzed via a PASS online tool to check their several pharmacological activities. The study is complemented by in silico molecular docking, pharmacokinetics, and molecular dynamics simulation studies. These studies discover 5D as a potential candidate for drug development, supported by its favorable drug-like properties, ADMET studies, docking interaction, and stable behavior in the protein binding cavity.

Author correction to “Enhanced property of thin cuprous oxide film prepared through green synthetic route”

This correction adds some information to our publication [Chin. J. Chem. Phys. 32, 365–372 (2019)] that we previously missed to include.

Biodegradable and biocompatible nonisocyanate polyurethanes synthesized from bio-derived precursors

Despite the enormous use of polyurethanes (PUs) in multiple aspects of modern lifestyle, the industrial scale manufacturing of PUs uses toxic chemicals like isocyanates, phosgene till today. In addition, the non-biodegradability and non-biocompatibility of PUs and their debris are serious cause of concerns for the environment. To deal with these challenges, in the current work, a new approach is reported in which bio-derived non-isocyanate polyurethanes were synthesized by exploiting viable amino acid-based diamines and biscyclocarbonates from sebacoyl chloride and diglycerol derivatives in a readily doable process. The newly designed polyhydroxyurethanes (PHUs) exhibited remarkable biodegradability and biocompatibility (cell viability) in comparison with commercial diamine based PHUs. A series of PHUs were synthesized in bulk and solvent free green synthetic route by polycondensing library of amino acids (such as glycine, alanine, valine, and isoleucine etc.) based diamines consisting of varying alkyl chain lengths and biscyclocarbonates like sebacic biscyclocarbonate and diglycerol biscyclocarbonate etc. All the synthesized PHUs were thoroughly characterised by IR, NMR and HRMS spectroscopic techniques. The impact of chain length and molecular structure of the synthesized PHUs were also evaluated using DSC, TGA, SEC, water contact angle measurements and hydrolytic degradation studies. The molar masses of the PHUs obtained from the SEC analysis are in the range of ∼17,000–24,000 Da. The current study demonstrated that amino acids is one of the major degradation products and are biocompatible in in-vitro conditions. The PHUs and their degradable products showed excellent cell viability when studied in HEK293T cells that were carried out using microgram to milligram concentration of PHUs. The outcome of this work in comparison to conventional PHUs and polyurethanes clearly demonstrated good biocompatibility and hence drawing attention to potential applications in bio-adhesives, bio-implants, drug delivery, and green coatings etc. in the near future.

Nitrophenol Reduction with Silver Oxide Nanostructures as a Sustainable Approach to Environmental Remediation.

We propose silver oxide as a cost-effective and sustainable alternative to noble metals for the catalytic reduction of nitroaromatics. In the present investigation, we adopt a facile and green synthetic route for the synthesis of silver oxide nanostructures. The prepared nanostructures were found to crystallize in the cuprite phase and exhibit absorbance across the entire visible range of the electromagnetic spectrum. The catalytic potential of the silver oxide was evaluated by following the kinetics of nitrophenol reduction under ambient conditions and is observed to follow pseudo-first order kinetics with the apparent rate constant s-1 at minimum concentration of the catalyst. We attribute the observed catalytic activity to the freshly generated catalytic surface featuring a partially reduced form of silver oxide during reaction. The findings highlight the efficacy of silver oxide in mitigating the environmental pollution originating from the recalcitrant nitroarenes.

2024 IUPAC-Zhejiang NHU International Award For Advancements In Green Chemistry—Call For Nominations

Abstract IUPAC-Zhejiang NHU International Award has been established in 2019 to emphasize the importance of advancements in Green Chemistry and the value of sciences to human progress, and to encourage young and experienced chemists. The award covers all the topics of Green Chemistry, such as Green and Renewable Feedstocks, Green Synthetic Routes, Green Solvents, Green Catalysis, Green products, Green Energy, and as broadly defined by OECD as Sustainable Chemistry. See http://www.oecd.org/chemicalsafety/risk-management/sustainablechemistry.htm and reference therein, including Proceedings of the 1999 workshop, ENV/JM/MONO(99)19/PART3, p. 204

Eco-Friendly Synthesis of CuO@ZnO Nanocomposites Using Artemisia vulgaris Leaf Extract and Study of Its Photocatalytic Activity for Methylene Blue

In this study, copper oxide nanoparticles (CuO NPs), zinc oxide nanoparticles (ZnO NPs), and copper oxide/zinc oxide nanocomposites (CuO@ZnO NPs) were synthesized by green synthetic route where bioactive compounds inherently present in the leaf extract of Artemisia vulgaris act as stabilizing and reducing agents. Phytochemicals present in leaf extract were assessed by qualitative chemical tests and spectroscopic measurements. UV-visible spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, Energy Dispersive X-ray (EDX) spectroscopy, X-ray Diffraction (XRD), and Field Emission Scanning Electron Microscopy (FESEM) were used to characterize the as-synthesized nanomaterials, i.e., CuO, ZnO, and CuO@ZnO NPs. XRD pattern revealed the crystalline nature of nanoparticles. Based on the Debye–Scherrer formula, the sizes of CuO NPs, ZnO NPs, and CuO@ZnO NCs were found to be 17.24, 20.74, and 22.50 nm, respectively. The band gap of the as-prepared nanomaterials was measured using the Tauc plot. Using the nanomaterials, MB degradation was studied at room temperature under exposure to UV light. The degradation efficiency of CuO, ZnO, and 2% CuO@ZnO was found to be 52%, 68%, and 98%, respectively. Kinetic degradation process reveals that the CuO@ZnO NCs showed a better photocatalytic activity on MB dye with the degradation constant of 0.04124 min−1 compared to those of either constituent. Based on the findings, it was found that CuO@ZnO nanocomposites have the potential to degrade MB as an organic dye and can be used for wastewater treatment.

Environmentally benign preparation of Ag nanoparticles & Ag-rGO nanocomposite and evaluation of their photocatalytic, sensing, antioxidant and antimicrobial activities

Environmental pollution and fossil fuel depletion are becoming major issues on a worldwide scale, posing serious threats to both the environment and human health. Finding effective and affordable pollution cleanup technologies as well as the alternate source of energy is very important. The present study is concerned with the synthesis of Ag nanoparticles and Ag-rGO composite employing environment affable and cost-effective green combustion method. The fuel used for the preparation of NPs was the Malus domastica juice. The synthesized materials were subjected for the characterization techniques like XRD, TEM, SEM, Raman and UV-Visible spectral studies. The synthesized nanocomposite was analyzed for photocatalytic dye degradation, electrochemical nitrate sensing, antibacterial as well as antioxidant activities. Ag-rGO degraded methylene blue dye completely by 70 min. Further, the material was subjected for recyclability test and it was efficient and stable upto 5th cycle. Effect of various parameters such as catalytic load, dye concentration and pH on efficiency of dye degradation was analyzed. Nitrite sensing studies revealed that the LOD was found to be 19.8 µg. Further, Ag-rGO exhibited antibacterial activity on Pseudomonas aeroginosa bacterial strain to a greater extent compared to all the other bacterial strains tested. The Ag-rGO nanocomposite was found to be the potent antioxidant with IC50 value of 1489 µg/mL. Therefore, this work exemplifies the easy and eco-friendly green synthetic route for the large-scale industrial production of versatile Ag-rGO nanocomposite.

Biosynthesis of CuFe2O4@Ag hybrid nanocomposite: Ultrasensitive detection and catalytic reduction of 4-nitrophenol

Due to the dearth of extremely capable, sensitive, and stable catalysts, the efficient detection and catalytic removal of 4-nitrophenol (4-NP) in industrial wastewater remains a serious challenge. The detection and determination of 4-nitrophenol (4-NP) presence in the environment is a matter of paramount importance because it is a high-priority hazardous pollutant that can affect people, animals, and plants. Here, we present a promising and economically viable green synthetic route for fabricating CuFe2O4 and CuFe2O4@Ag hybrid nanocomposites from the leaf extract of Senna didymobotrya. The UV–Vis, FTIR, XRD, FE-SEM, EDXA, BET and VSM analysis were performed to characterize the synthesis of CuFe2O4@Ag nanocomposite. To evaluate the electrocatalytic capacity of CuFe2O4@Ag, electrochemical sensing stratergy was performed with cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The modified CuFe2O4@Ag glassy carbon electrode (GCE) (CuFe2O4@Ag/GCE) demonstrated a linear response in the range of 0.01-15 μg/ml (71 nm-107 μM) and the ability to detect 4-NP at low concentration (0.006 μg/ml (43 nM)). Due to the increased surface area of CuFe2O4@Ag/GCE by ̴ 1.5-fold, a greater cathodic current response (-16 μA/cm2) at a low potential of -0.81 V was observed compared to CuFe2O4/GCE alone for the detection of 4-NP. Additonally, CuFe2O4@Ag showed excellent reduction ability towards 4-NP using NaBH4 with an efficiency of 96.4 % which was higher than the CuFe2O4 (only 87.3 %) in 12 min due to the synergistic relationship among Ag NPs and CuFe2O4 nanostructures. The outcomes from this study shows that the bi-functional electrocatalyst holds vast potential for environmental remediation.

Tailoring plasmonic sensing strategies for the rapid and sensitive detection of hypochlorite in swimming water samples.

Atunable plasmonic sensor has been developedby varying the dextran content in the initially synthesized dextran-gold nanoparticle (dAuNPs) solution. A colloidal nanogold solution (dAuNPs-Sol) was initially prepared using dextran and gold salt in alkaline media by a one-pot green synthetic route. The dAuNPs-Sol was combined with varying amounts of dextran (ranging from 0.01 to 30.01%) to create a tunable probe, along with different solid formats, including tablet (dAuNPs-Tab), powder (dAuNPs-Powder), and composite (dAuNPs-Comp). Both the liquid and solid phase plasmonic probes were characterized using UV-vis spectroscopy, transmission electron microscopy (TEM) dynamic light scattering (DLS), and zeta potential analysis. The impact of dextran content in the dAuNP solution is studied in terms of surface charge and hydrodynamic size. The influence of operational treatments used to achieve solid dAuNPs probes is also explored. All plasmonic probes were employed to detect a broad range of OCl¯ concentrations (ranging from µM to mM) in water through aggregation followed by calculating a lower and upper limit of detection (LLoD, ULoD) of the proposed colorimetric sensors. Results indicate that the most sensitive detection is achieved with a lower dextran content (0.01%), which exhibits an LLoD of 50µM. The dAuNPs-Sol sensor is selective and demonstrates real-world applicability, as confirmed by interference analysis and successful testing with various water samples. Additionally, it is found that a 20 × concentration of dextran-coated gold nanoparticles could be attained without any changes in the particle morphology. This concentration is achieved through a straightforward process that does not require the use of a centrifuge machine. This finding highlights the practicality and simplicity of the method, indicating its potential for scalable and cost-effective production of concentrated dAuNPs without compromising their structural integrity.

β-NaBiF4:Yb3+,Er3+:Novel green synthesis, crystal structure, upconversion luminescence and optical thermometry

Non-lanthanide based NaBiF4 host have evoked remarkable interest due to unique luminescent property and potential applications. Current synthetic methods are not environment friendly and causes pollution. This is the first report mentioning green synthetic innovative route to develop upconversion, crystalline, and temperature sensing material. Here, we deigned ultrasonic assisted green approach for successful synthesis of β-NaBiF4:Yb3+, Er3+ (size ∼25–100 nm) using Tabernaemontana divaricata leaves extract without any surfactant. Characterization techniques such as XRD, SEM, TEM, XPS, EDX, and PL unveiled its properties. Green and red upconversion emissions (λex = 980 nm) were two-photon absorption process. The possible energy transfer and thermal quenching mechanism is discussed. Using thermally coupled levels (2H11/2 and 4S3/2) of Er3+, FIR based temperature sensing revealed ΔE ∼841 cm−1, linear response (R2 ∼0.99), outstanding relative sensitivity (Sr max∼ 1.4 % K−1 @294 K), good absolute sensitivity (Sa max∼ 0.29 %K−1 @ 398 K) and a low temperature resolution (δTmin = 0.35 K) over temperature range 294–398 K.

Deep analysis of adsorption isotherm for rapid sorption of Acid Blue 93 and Reactive Red 195 on reactive graphene.

Graphene-based adsorbent was prepared by adopting a green synthetic route via the chemical exfoliation of graphite and low-temperature thermal activation. Prepared reactive graphene (RG) was characterized through various techniques, and its adsorption capabilities for textile dye removal were investigated for Acid Blue-93 (AB) and Reactive Red-195 (RR) under different operational conditions. The dye sorption equilibrium and mechanism were comprehensively studied using isotherm and kinetic models and compared statistically to explain the sorption behavior. Results show AB and RR adsorption by RG attains equilibrium in 60min and 70min, with a high sorption quantity of 397mgg-1 and 262mgg-1 (initial dye concentration of 100mg L-1), respectively. The dye sorption anticipates that the high surface area (104.52 m2 gm-1) and constructed meso-macroporous features of RG facilitated the interaction between the dye molecules and graphitic skeleton. The R-P isotherm fitted the best of equilibrium data, having the least variance in residuals for both dyes (AB = 0.00031 and RR = 0.00047). The pseudo-second order model best fitted the kinetics of sorption on RG, with chemisorption being the predominant process delimiting step. The overall results promise the dye removal capability of RG to be an efficient adsorbent for azo-based dyes from textile effluents.

Green synthesis of AgNPs from leaves extract of Saliva Sclarea, their characterization, antibacterial activity, and catalytic reduction ability

Abstract Several technologies are employed for the synthesis of silver nanoparticles, each synthesis technique has advantages and disadvantages, and the best technique relies on the application at hand, the required qualities of the nanoparticles, and the size of the product. But in this article green synthesis were followed. In this research, AgNPs were synthesized using Salvia Sclarea leaf extract in green synthetic routes. The synthesized nanoparticles were examined using UV–vis spectroscopy, powder XRD, SEM, and FT-IR. Here three different type of silver nanoparticles were biosynthesized, AgNPs-1, AgNPs-2, and AgNPs-3 (where composition of AgNO3 and extract were 6:1, 10:1 and 14:1 respectively). The catalytic ability of AgNPs 1–3 was determine in the reduction of nitro-compounds into corresponding amines, where AgNPs-2 was found efficient reductive catalyst. Moreover, antibacterial activities were checked against both gram-positive (Bacillus Suntilis) and gram-negative bacteria (Klebsiella pneumoniae). Upon increasing Ag contents antibacterial activities were found in increasing mode. Which open new era of knowledge for further consideration.

Zinc selenide quantum dots as fluorescent labels for biomedical imaging

We, herein, report a facile green synthetic route for the gram‐scale synthesis of high‐quality thiol‐derivatized zinc selenide quantum dots (QDs) using selenourea as the source of selenium at a relatively low temperature. The one‐pot synthesis of colloidal dots has been achieved by selenizing zinc (II) acetate in a non‐coordinating solvent medium. The structural, microstructural, optical, thermal, textural and electronic properties of the as‐synthesized monodisperse ZnSe dots have been investigated in detail. We attribute the observed green emission from the dots to the donor‐acceptor pair (DAP) recombination of photoexcited charge carriers. All the findings of the investigation indicate that ZnSe QDs hold great promise as a nanoscale emissive probe to unveil cellular dynamics beyond the capabilities of conventional imaging techniques.

Chemoenzymatic multistep retrosynthesis with transformer loops.

Integrating enzymatic reactions into computer-aided synthesis planning (CASP) should help devise more selective, economical, and greener synthetic routes. Herein we report the triple-transformer loop algorithm with biocatalysis (TTLAB) as a new CASP tool for chemo-enzymatic multistep retrosynthesis. Single-step retrosyntheses are performed using two triple transformer loops (TTL), one trained with chemical reactions from the US Patent Office (USPTO-TTL), the second one obtained by multitask transfer learning combining the USPTO dataset with preparative biotransformations from the literature (ENZR-TTL). Each TTL performs single-step retrosynthesis independently by tagging potential reactive sites in the product, predicting for each site possible starting materials (T1) and reagents or enzymes (T2), and validating the predictions via a forward transformer (T3). TTLAB combines predictions from both TTLs to explore multistep sequences using a heuristic best-first tree search and propose short routes from commercial building blocks including enantioselective biocatalytic steps. TTLAB can be used to assist chemoenzymatic route design.

Single transition atom-doped antimonene as a highly efficient electrocatalyst for the nitrogen reduction reaction: a DFT study

The synthesis of ammonia (NH3) through the electrocatalytic nitrogen reduction reaction (NRR) at ambient temperature and pressure provides a green low-carbon synthetic route for ammonia production.

Rapid continuous aqueous production of copper indium sulfide quantum dots via a microwave-assisted microfluidic technique.

Ternary copper indium sulfide (CIS) quantum dots (QDs) have been emerging as attractive alternatives to Cd- and Pb-based QDs in various applications owing to their favorable optical properties and low toxicity. However, methods allowing continuous production of CIS QDs in an easy-to-perform and/or organic-solvent-free way are yet to be realized. Here, we report a facile, rapid, continuous, and aqueous synthetic approach for CIS QDs based on a microwave-assisted microfluidic (MAM) technique with easy scale-up of production. Typically, CIS QDs and CIS@ZnS QDs are continuously produced with a flow rate of 30 mL h-1 at a moderate temperature (∼95 °C) in an open-air system with a continuous flow of water as the reaction medium. This continuous synthesis process circumvents the requirements of batch operation, a degassed/inert atmosphere, high temperatures, organic solvents, and complex/expensive equipment. The resulting water-soluble CIS@ZnS QDs show a photoluminescence quantum yield of 44%. This work provides an efficient and green synthetic route for the scalable production of fluorescent nanomaterials.