Green Synthesis Route Research Articles

Sunlight assisted degradation of methylene blue dye by zinc oxide nanoparticles green synthesized using Vitex negundo plant leaf extract

Zinc oxide nanoparticles (ZnO NPs) were formed through a simple green synthesis route using Vitex negundo (V. negundo) leaf extract as reducing and capping source. Morphological, structural, chemical and optical features of the prepared ZnO NPs were examined by field emission SEM, XRD, EDAX, PL, FTIR and UV–vis DRS, respectively. FESEM images precisely visualized morphology of the ZnO NPs as spherical with particles size ranges between 5 and 35 nm having a mean diameter of ∼ 19 nm. XRD pattern revealed formation of hexagonal wurtzite structured ZnO NPs with high crystallinity. Further, the observed asymmetric stretching vibration of Zn-O bond confirmed the formation of hexagonal wurtzite structured ZnO NPs. Photocatalytic activity of the ZnO NPs was assessed against methylene blue (MB) dye degradation under natural sunlight illumination. Results of the photocatalytic experiment disclosed an impressive MB dye degradation efficiency of 98.50 % at 60 min. Moreover, green synthesized ZnO NPs exhibited a maximum mineralization (TOC removal) efficiency of 92.34 % at 5 h of sunlight illumination.

Microwave Assisted Zinc Sulphide Quantum Dots for Energy Device Applications

Zinc sulfide (ZnS) quantum dots (QDs) have received a lot of attention because of their potential usage in solar cell applications. The present work illustrates a straightforward green synthesis route for ZnS QDs, which is both cost-effective and environmentally friendly. The phase identification of the synthesized material was performed through the X-ray diffraction technique which revealed the presence of single-phase zinc sulfide. The crystallite size was calculated through various techniques such as Debye Scherrer’s, Williamson Hall and Size-Strain plot revealing quantum confinement effects. High-resolution transmission electron microscope (HR-TEM) revealed the presence of quantum dots within the quantum size range and demonstrated excellent quantum yield. However, the decrease in the particle size has increased the band gap for ZnS QDs to 3.4 eV with a refractive index of 2.29. The polycrystalline character of the as-synthesized ZnS was shown by the selected area electron diffraction (SAED) pattern of the corresponding TEM images. Morphological analysis, carried out via field emission scanning electron microscopy (FESEM), unveiled the existence of zinc sulfide quantum dots agglomerates. Elemental composition analysis was performed using energy dispersive spectroscopy (EDS) as an attachment to FESEM, which confirmed the existence only of zinc and sulphur.

MODIFIED MAGNETITE NANOPARTICLES WITH THE JUICE OF PLANTAIN PSEUDOSTEM: AN OPTION FOR WATER DECONTAMINATION

In recent years, various methods for surface functionalization of magnetite nanoparticles with emerging modifications have been explored and reported. Green nano-chemistry aims to synthesize nanomaterials using bio-based resources, providing new materials for biological and environmental applications. Surface modification of magnetite nanoparticles using phytochemicals extracted from plants is a fundamental principle of green synthesis routes. Agricultural waste from different crops, such as plantain pseudostem, is of particular interest as a renewable resource due to its abundant availability, low toxicity, and economic feasibility. In this study, the juice extracted from plantain pseudostem was utilized for the phytofunctionalization of magnetite nanoparticles. Characterization techniques including transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), and fourier-transform infrared spectroscopy (FTIR) confirmed the nanometric dimensions of the composite (size range of 12.6 ± 3.17 nm) and established its organic-inorganic nature. The superparamagnetic properties of the composite were also demonstrated. Moreover, the potential application of this nanohybrid in bioremediation for the immobilization of cadmium(II) and lead(II) showed promising results, highlighting its efficacy in managing water pollutants.

Green route synthesis of transition metal doped V2O5 nanoparticles, with emerging biomedical applications

In this proposed work we synthesized the pristine V2O5 nanoparticles and Ag (3.2 % (SV-1), 14.5 %, (SV-5) 23.4 % (SV-9), Cd (5.8 % (CV-1), 23.5 % (CV-5), 35.7 % (CV-9)) and Ru doped (4.9 % (RV-1), 20.7 % (RV-5), 32 % (RV-9)) V2O5 nanoparticles using vigna radiata extract. The nanoparticles were characterized by various techniques like UV-DRS, FT-IR, XRD, FE-SEM and HR-TEM. The antibacterial activities of nanoparticles were studied using bacterial strains such as Staphylococcus aures (S.aureus), Streptococcus pneumoniea (S. pneumoniea), Pseudomonas aeruginosae (P. aeruginosae), Klebsiella pneumoniea (K. pneumoniea) and Escherichia coli (E.coli). Among the nanoparticles the potential bacterium growth inhibition of 99 % for S.aureus was observed for CV-5. The binding efficiency of the nanoparticles with the biomolecule BSA was studied by using UV–visible absorption and emission spectral techniques. It was found that there is a binding interaction between them and the binding constant values are in the range from 104 to 105 M−1. The quenching rate constant (kq) value is bigger than the maximum diffusion constant of biomolecules 2.0 x 1010M−1s−1 suggesting that the interaction is static quenching type. In glucose oxidation studies lower potential with a high current density of 440 mA/cm2 occurred for pristine V2O5 NPs.

Green Synthesis of ZnO/CuO Nanocomposite Using Punica granatum for the Enhanced Photocatalytic Performance

Zinc oxide nanoparticles (ZnO NPs) and zinc oxide/copper oxide (ZnO/CuO) nanocomposites were constructed via green-synthesis route involving the use of Punica granatum seed extracts through microwave method. The as-synthesized samples were investigated for their catalytic activities. The fabricated nanomaterials were characterized using UV-visible spectroscopy (UV-vis), X-ray diffraction (XRD), Energy dispersive spectroscopy (EDS), Dynamic light scattering (DLS) spectroscopy, Field emission scanning electron microscopy (FE-SEM) and high-resolution transmission electron microscopy (HR-TEM). The peak observed at 385 nm in the surface plasmon resonance of ZnO NPs suggests the formation of nanoparticles of different sizes. The successful synthesis of composite was inferred from the shifting of UV-vis absorbance peak. Furthermore, the band gap energy of ZnO/CuO (with 10 wt.% of CuO precursor) was obtained to be 2.52 eV which was found lesser than that of nanoparticles. Phase morphology studied via XRD revealed the nanoparticles of crystalline nature. The mean crystallite size of extract mediated ZnO NPs and ZnO/CuO nanocomposites were found to be 61.5 and 53 nm, correspondingly. Similarly, morphological analysis of as-synthesized nanoparticles via HR-TEM showed the irregular to roughly spherical shape with size 100-200 nm. Nanomaterials generated in this manner were employed for the catalytic reduction of toxic 4-nitrophenol. The ZnO/CuO (with 10 wt.% of CuO) nanocomposites showed the higher degradation efficiency towards reduction of 4-nitrophenol compared to ZnO/CuO (5 wt.%) nanocomposites.

Solventless mechanochemical synthesis of Sn-based halide perovskite microcrystals with high stability tracked by photoluminescence spectroscopy

Developing solvent-free methods to synthesize lead-free perovskites is of practical importance from the viewpoint of sustainability. In this work, we use a facile mechanochemical approach to synthesize a series of lead-free Sn-based halide perovskite microcrystals (powders) in ambient conditions directly from precursor powders (CsX and SnX2 (X = I, Br, Cl)) without any solvent. Such an approach is energy-saving and avoids the use of toxic solvents. There exists phase evolution during the mechanochemical processing of the precursor powders with CsSn2Br5 to CsSnBr3 in the first hour and finally into the stabilized phase of Cs2SnBr6 after 28 days and with Cs2SnCl4 to CsSnCl3 in the first hour and finally to the stabilized phase of Cs2SnCl6 after 36 days. The stabilized Cs2SnI6 powders emit light centered at 930 nm under the excitation of 785 nm, and the stabilized Cs2SnBr6 powders emit light centered at 682 nm under the excitation of 365 nm. Both the stabilized Cs2SnI6 and Cs2SnBr6 powders exhibit excellent long-term structural and optical stabilities, and the Cs2SnBr6 powders have a better thermal stability than the Cs2SnI6 powders. This work likely offers a green-route synthesis of lead-free halide perovskites towards large-scale manufacturing and industrialization.

Nanosilver-decorated reduced graphene oxide for catalytic carboxylation of phenylacetylene with CO2

Nanosilver/reduced graphene oxide (AgNPs/rGO) nanocomposite by the green synthesis route was investigated using urea as a green reductor. The characterization of the AgNPs/rGO was confirmed by UV–Vis spectroscopy, FT-IR, XRD, Raman Spectroscopy, FE-SEM, Energy Dispersive X-ray (EDX), and TEM. The characterization result showed that the AgNPs/rGO was successfully synthesized by green reduction using urea, and the AgNPs were well-spread on the surface of the rGO. AgNPs/rGO nanocomposite was used as a catalyst towards the synthesize of phenylpropiolic acid from phenylacetylene carboxylation with CO2. The difference in the base used and reaction temperature influenced the carboxylation of phenylacetylene with CO2. The nanocomposite shows excellent selectivity towards phenylpropiolic acid. The highest conversion was obtained from the reaction using Na2CO3 at the temperature of 50 °C. Phenylpropiolic acid was formed as a major product with a high selectivity of 99.5%. The reusability of AgNPs/rGO nanocomposite as a carboxylation catalyst maintained an excellent selectivity above 99% even after third cycle.

Nanocrystal engineering: Unraveling bioactivities and augmented photocatalytic degradation of ZnO and Cr-doped ZnO via green and chemical synthesis routes

Herein, we focused on the combined investigation of physicochemical traits and multifunctional bioactivity of ZnO and Cr-doped ZnO NPs synthesized by chemical and green synthesis methods. The green synthesis was accomplished by utilizing Azadirachta Indica leaf extracts which include the phytochemicals azadirachtin and nimbolide function as prominent therapeutic agents in diagnosis. The XRD and TEM analysis evidences all the prepared NPs exhibit hexagonal wurtzite structure, and the change in crystallinity of ZnO NPs with Cr substitution has been examined. The optical properties show that Cr inclusion effectively changes the optical band gap of pure ZnO NPs, confirming the quantum confinement effect. The synthesized NPs were employed to investigate photocatalytic degradation of Rhodamine B (Rh B) dye in an aqueous environment under UV irradiation. The Rh-B dye effectively degraded within 180 min in the presence of synthesized nano catalyst at room temperature. Further, the synthesized NPs were subjected to investigate their bio-potency for microbicidal and cytotoxicity properties. The biosynthesized Cr-ZnO NPs exhibit significant cytotoxicity against A-549 lung cancer cells with the lowest IC50 value (21.79 µg/ml) and also demonstrate good antioxidant activity with the highest percentage of inhibition 81.23 % as measured by the DPPH scavenging assay in contrast to other NPs. In addition, the chemically synthesized Cr-ZnO NPs found the highest inhibition activity (90.78 %) for antidiabetic efficiency of Alpha-amylase enzyme assay and also shows significant antibacterial activities with a higher zone of inhibition (17 mm) against gram-positive Bacillus cereus over other samples. Thus, this study highlights ZnO NPs versatile attributes, paving the way for promising biomedical and environmental uses.

Nitrogen-doped lychee-like saccharide-based carbon microspheres with high-performance microwave absorption

The reasonable design of multiple interfaces and heteroatom doping can substantially improve the wave-absorbing performance of electromagnetic wave (EMW) absorbing materials. As the carbon source of biomass, the carbon material with abundant oxygen-containing groups on the surface can be obtained by hydrothermal method, which is conducive to modification and design of the morphology. In addition, N-hydroxymethyl acrylamide contains rich N atoms and has good water solubility, which can be well combined with sugar to prepare high-performance wave-absorbing materials. In this study, D-xylose and glucose were used as carbon sources, water was used as solvent, N-hydroxymethyl acrylamide was added, and nitrogen-doped lychee-like saccharide-based carbon microspheres (LSCMs) were obtained by hydrothermal synthesis and high-temperature carbonization. LSCMs-2 with good EMW attenuation capability and impedance matching performance was obtained by controlling the proportion of different raw materials. Under the optimal filling conditions, the EMW absorber is only 2 mm thick and achieves a minimum reflection loss (RL min) of −47.44 dB at 13.84 GHz with an effective absorption bandwidth (EAB) of 12.24–17.36 GHz (5.12 GHz). The excellent EMW attenuation performance is mainly attributed to dipole polarization and interface polarization in the LSCMs. This research offers a new green synthesis route for the preparation of EMW absorbers with wider bandwidth, thinner thickness and better absorption performance.

An In situ Proton Filter Covalent Organic Framework Catalyst for Highly Efficient Aqueous Electrochemical Ammonia Production

AbstractThe electrocatalytic nitrogen reduction reaction (NRR) driven by renewable electricity provides a green synthesis route for ammonia (NH3) production under ambient conditions but suffers from a low conversion yield and poor Faradaic efficiency (F.E.) because of strong competition from hydrogen evolution reaction (HER) and the poor solubility of N2 in aqueous systems. Herein, an in situ proton filter covalent organic framework catalyst (Ru‐Tta‐Dfp) is reported with inherent Ruthenium (Ru) sites where the framework controls reactant diffusion by suppressing proton supply and enhancing N2 flux, causing highly selective and efficient catalysis. The smart catalyst design results in a remarkable ammonia production yield rate of 2.03 mg h−1 mgcat−1 with an excellent F.E. of ≈52.9%. The findings are further endorsed with the help of molecular dynamics simulations and control COF systems without in situ proton filter feasibility. The results point to a paradigm shift in engineering high‐performance NRR electrocatalysts for more feasible green NH3 production.

An eco-friendly route for green synthesis of ZnO-CoFe2O4 nanoparticles from cardamom and ginger extract as an efficient electrochemical catalyst for water oxidation

Water splitting has been one of the potential techniques as a clean and renewable energy resource for the fulfillment of world energy demands. One of the major aspects of this procedure is the exploitation of efficient and inexpensive electrocatalysts due to the fact that the water oxidation procedure is accompanied by a delayed reaction. In this research, ZnO-CoFe2O4 nanostructure was successfully synthesized via the green method and green resources from cardamom seeds and ginger peels for oxygen evolution reaction (OER). The modified Glassy carbon electrode (GCE) with ZnO-CoFe2O4 is effective for the electrochemical water oxidation interaction since it has sufficient electrical strength and excellent catalytic performance. The creation of rice-like and small granular structures of ZnO-CoFe2O4 nano-catalysts was confirmed by characterization methods such as XRD, FESEM, EDS and MAP. According to the achieved results, in the electrolysis of water, with in-cell voltage of 1.40 V and 50 mA cm–2 for current density in a 0.1 M KOH electrolyte and OER only has 170 mV overpotentials.

Facile Synthesis of Ni-Doped ZnO Nanoparticles Using Cashew Gum: Investigation of the Structural, Optical, and Photocatalytic Properties

This work adopted a green synthesis route using cashew tree gum as a mediating agent to obtain Ni-doped ZnO nanoparticles through the sol–gel method. Structural analysis confirmed the formation of the hexagonal wurtzite phase and distortions in the crystal lattice due to the inclusion of Ni cations, which increased the average crystallite size from 61.9 nm to 81.6 nm. These distortions resulted in the growth of point defects in the structure, which influenced the samples’ optical properties, causing slight reductions in the band gaps and significant increases in the Urbach energy. The fitting of the photoluminescence spectra confirmed an increase in the concentration of zinc vacancy defects (VZn) and monovacancies (Vo) as Zn cations were replaced by Ni cations in the ZnO structure. The percentage of VZn defects for the pure compound was 11%, increasing to 40% and 47% for the samples doped with 1% and 3% of Ni cations, respectively. In contrast, the highest percentage of VO defects is recorded for the material with the lowest Ni ions concentration, comprising about 60%. The influence of dopant concentration was also reflected in the photocatalytic performance. Among the samples tested, the Zn0.99Ni0.01O compound presented the best result in MB degradation, reaching an efficiency of 98.4%. Thus, the recovered material underwent reuse tests, revealing an efficiency of 98.2% in dye degradation, confirming the stability of the photocatalyst. Furthermore, the use of different inhibitors indicated that •OH radicals are the main ones involved in removing the pollutant. This work is valuable because it presents an ecological synthesis using cashew gum, a natural polysaccharide that has been little explored in the literature.

Green synthesis of ZnO nano-crystals using Chenopodium album L. Leaf extract, their characterizations and antibacterial activities

We present an effective, simple and eco-friendly method for the green synthesis of ZnO nano-crystals. An aqueous extract of Chenopodium album leaf was used as a biological reducing agent for the fabrication of ZnO nano-crystals from the zinc sulphate heptahydrate. The as-prepared and annealed powder samples were characterized using advanced techniques. The results confirmed the presence of ZnO crystals with a broad size distribution, whose crystallinity was noticed to improve substantially after the annealing. Further, in antibacterial activity test of ZnO nano-crystals performed on Escherichia coli and Staphylococcus aureus microorganisms, inhibitory effect was found to increase with concentration. Compared to Gram-positive bacteria, ZnO nano-crystals showed more resistance to Gram-negative bacteria. This green synthesis route of ZnO nano-crystals is novel and aims to reduce the use of toxic chemicals in fabricating the nanoparticles of functional oxides, which have a wide range of potential applications in general and biomedical science, in particular.

Photosynthesis of Benzonitriles on BiOBr Nanosheets Promoted by Vacancy Associates

AbstractPhotocatalytic organic functionalization reactions represent a green, cost‐effective, and sustainable synthesis route for value‐added chemicals. However, heterogeneous photocatalysis is inefficient in directly activating ammonia molecules for the production of high‐value‐added nitrogenous organic products when compared with oxygen activation in the formation of related oxygenated compounds. In this study, we report the heterogeneous photosynthesis of benzonitriles by the ammoxidation of benzyl alcohols (99 % conversion, 93 % selectivity) promoted using BiOBr nanosheets with surface vacancy associates. In contrast, the main reaction of catalysts with other types of vacancy sites is the oxidation of benzyl alcohol to benzaldehyde or benzoic acid. Experimental measurements and theoretical calculations have demonstrated a specificity of vacancy type with respect to product selectivity, which arises from the adsorption and activation of NH3 and O2 that is required to promote subsequent C−N coupling and oxidation to nitrile. This study provides a better understanding of the role of vacancies as catalytic sites in heterogeneous photocatalysis.

Photosynthesis of Benzonitriles on BiOBr Nanosheets Promoted by Vacancy Associates.

Photocatalytic organic functionalization reactions represent a green, cost-effective, and sustainable synthesis route for value-added chemicals. However, heterogeneous photocatalysis is inefficient in directly activating ammonia molecules for the production of high-value-added nitrogenous organic products when compared with oxygen activation in the formation of related oxygenated compounds. In this study, we report the heterogeneous photosynthesis of benzonitriles by the ammoxidation of benzyl alcohols (99 % conversion, 93 % selectivity) promoted using BiOBr nanosheets with surface vacancy associates. In contrast, the main reaction of catalysts with other types of vacancy sites is the oxidation of benzyl alcohol to benzaldehyde or benzoic acid. Experimental measurements and theoretical calculations have demonstrated a specificity of vacancy type with respect to product selectivity, which arises from the adsorption and activation of NH3 and O2 that is required to promote subsequent C-N coupling and oxidation to nitrile. This study provides a better understanding of the role of vacancies as catalytic sites in heterogeneous photocatalysis.

Augmented Catalytic Performance of PVA- Assisted Fe2O3 Nano Catalyst for Water Treatment Synthesized via Green Route

Abstract Metal oxides (MO) are widely preferred for removing various effluents from water and air; however due to poor utilization of visible light, the application of MO nanoparticles for water treatments is hindered. This work reports the synthesis of ring-structured PVA-assisted Fe2O3 (P-Fe2O3) nanocomposite through a green route synthesis, for the elimination of methylene blue via sunlight triggered photocatalyst. FTIR spectroscopy confirmed the presence of desired functional groups in novel ring-structured Fe2O3 and PVA-assisted Fe2O3 (P-Fe2O3) nanocomposite. The crystallinity of Fe2O3 was also studied through XRD. Surface topography of Fe2O3 was examined through FE-SEM, that reveals a central hole with extended surface area of Fe2O3. UV-vis-spectroscopy is used to evaluate photocatalytic efficiency which shows, pristine Fe2O3 exhibited 37% degradation in stipulated time intervals of 30~120 mins. The photocatalytic efficiency of augmented P-Fe2O3 nanocomposite expelled 82% of the methylene blue in span of just 02 hours. The stability of the developed nanocomposite in the effluent medium was investigated through FTIR by observing the change in carboxyl adsorption band produced during degradation of PVA, that manifests the fact that no degradation was witnessed for PVA even after 120 min, that makes P-Fe2O3 a promising material for the degradation of AZO dyes.

Graphdiyne as an Electron Modifier for Boosting Electrochemical Production of Adipic Acid

AbstractAdipic acid (AA) is a crucial feedstock for nylon polymers, and is industrially produced by thermal oxidation of cyclohexanone/cyclohexanol mixture (KA oil). However, this process consumes large quantities of corrosive nitric acid as oxidants, while emits ozone‐depleting greenhouse gas N2O. Here, an electrocatalytic strategy for selective oxidation of KA oil to AA coupled with H2 evolution over a Co3O4/graphdiyne cooperative catalyst (Co3O4/GDY) is reported. The Co3O4/GDY displays high electrooxidation activity of KA oil to AA (100 mA cm−2 at ≈1.5 V vs RHE), outperforming all the reported findings. Detailed ex situ and in situ experimental studies, theoretical calculations, and molecular dynamic simulations reveal that GDY not only facilitates the enrichment of cyclohexanone on the catalyst surface in aqueous medium, but also upshifts the d‐band center of Co sites, strengthening the adsorption/activation of cyclohexanone. This study offers a green route for AA synthesis and proposes a GDY interface engineering strategy for efficient electrooxidation.

Two spin-valve GMR thin films on half wheatstone bridge circuit for detecting green-synthesized Fe3O4@Ag nanoparticles-labeled biomolecule

The availability of low-cost, rapid, and easy-to-use instruments for detecting biomolecules is critical in giant magnetoresistance (GMR) based biosensors. This research reports the performance of two spin-valve (SV) GMR thin films on half Wheatstone bridge circuits for detecting biomolecules. The SV thin films with the structure of Ta(2 nm)/Ir20Mn80(10 nm)/Co90Fe10(3 nm)/Cu(2.2 nm)/Co84Fe10B4(10 nm)/Ta(5 nm) used as sensing element was fabricated using RF magnetron sputtering on Si/SiO2 substrate. The Fe3O4 magnetic nanoparticles as a label were synthesized by coprecipitation method based on the green synthesis route using Moringa oleifera (MO) extract. Furthermore, the utilization of Ag nanoparticles to form Fe3O4@Ag was also green-synthesized by the aqua-solution method using MO extract. The nanoparticles exhibited soft ferromagnetic behavior with the saturation magnetization of 55.0 emu/g for Fe3O4 and 43.4 emu/g for Fe3O4@Ag. A small amount of magnetic nanoparticles-ethanol solution was dropped onto each sensing element surface on half Wheatstone bridge. For comparison, one thin film was also investigated as a quarter Wheatstone bridge circuit. Based on this research, two sensors have faster magnetic switching and saturation than one sensor, confirmed by the left-shifting of Hs(sv) from 12.4 Oe down to 10.5 Oe for two sensors of the Fe3O4 sample. BSA is used as a biomarker to observe the performance of biosensors. The sensor on the half-bridge circuit in detecting Fe3O4@Ag/BSA achieved a better sensitivity of 0.51 mV/mg/mL than that of the quarter bridge of 0.46 mV/mg/mL. A small limit-of-detection of 0.5 mg/mL was achieved for Fe3O4@Ag/BSA. Moreover, the excellent reproducibility and stability of the sensor were confirmed by relative signal deviation ranges of 2–13 % for 60 s. Therefore, the half-bridge configuration is reliable for achieving competitive performance with green-synthesized magnetic labels in GMR as biosensors in encouraging more responsive detection.

Functionalized cellulose microfibers as reductant agent to gold nanoparticles and its application on SERRS for sensitive detection of phthalocyanine dye

Cellulose-based materials have drawn great attention in the world due to its abundance, renewable source, biodegradability, and easy functionalization of structure. Herein, microfibrillar cationic dialdehyde cellulose (CMF) using Girard's reagent T was produced. The functional groups of CMF were employed to reduce gold(III) into nanoparticles (AuNPs) which remain anchored on the fibers, designing a never-before encountered hybrid CMF/AuNPs. The AuNPs are well-dispersed, presenting an average size of 25 nm. The CMF showed an excellent reducing agent without any other chemicals, providing a green synthesis route. The novel hybrid was applied as substrate for surface-enhanced resonance Raman scattering (SERRS) spectroscopy to nickel(II) tetrasulfonated phthalocyanine (NiTsPc) detection as a proof-of-principle. A detection limit (LOD) in order of 10-7 mol/L and a quantification limit (LOQ) of 3.58 × 10-7 mol/L for the band at 1359 cm-1 were found. The CMF/AuNPs held considerable promise as an effective SERRS substrate for sensitive detection and quantification of trace molecules.

Highly atom-economic synthesis and scale-up production of zinc-aluminum layered double hydroxides

ZnAl layered double hydroxides (LDHs) has been widely applied as functional additives in polymers. The common coprecipitation method used to synthesize ZnAl LDHs has an atomic utilization of only 44.35 %, and is accompanied with the formation of sodium salt by-product, ZnO impurities and lots of waste water. In this work, we proposed a green and cost-effective synthesis route with 100 % atom economy to prepare ZnAl LDHs from mixed metal oxides and hydroxides. Pure ZnAl LDHs was synthesized at 120 °C. A dissolution-nucleation-diffusion reaction mechanism was proposed through structural and morphological studies and reaction kinetics calculations. The prepared ZnAl LDHs exhibited excellent smoke suppression properties, with a reduction in the smoke density of PVC from 705 to 340. This proposed method was successfully scaled-up and applied on a 1000 t/a industrial production line, providing a valuable opportunity for the reaction design and large-scale preparation of LDHs and other inorganic compounds.