Green Preparation Research Articles

Green preparation and isolation of carrageenan oligosaccharides and assessment of their ability to inhibit melanogenesis

An efficient method was developed for generating carrageenan oligosaccharides, a high-value material with health benefits for humans. The study used microwave-assisted mild acid hydrolysis of κ-carrageenan to achieve complete liquefaction. Under optimal reaction conditions, the yield of κ-carrageenan disaccharide (KCO2) was 22.90% ± 0.80%, with a total sugar product recovery rate of approximately 90%, while retaining the sulfate groups. Different degrees of polymerization (DP) carrageenan oligosaccharides with 4-sulfate-D-galactose (D-G4S) as the non-reducing end were obtained, with purities of over 90% for both KCO2 and κ-carrageenan tetrasaccharide (KCO4). KCO2 was identified as the oligosaccharide with the highest tyrosinase inhibitory activity. Enzyme kinetics studies revealed that KCO2 exhibited typical reversible competitive inhibition, with an IC50 of 1.09 ± 0.04 mg/mL and a Ki value of 0.16 ± 0.01 mg/mL. Molecular docking showed that KCO2 primarily interacted with key His residues at the tyrosinase active site through its sulfate groups. Molecular dynamics (MD) simulations indicated that the KCO2-tyrosinase complex structure was stable. These findings show that the carrageenan oligosaccharides generated by this strategy could be used as tyrosinase inhibitors in the food, cosmetic, and nutraceutical fields.

Green preparation of high-efficiency mesoporous MoP electrocatalyst for hydrogen evolution

Green preparation of high-efficiency mesoporous MoP electrocatalyst for hydrogen evolution

Efficient and green preparation of baicalein from Radix scutellariae with deep eutectic solvent pretreated bioconversion of cellulose-based microreactor

Efficient and green preparation of baicalein from Radix scutellariae with deep eutectic solvent pretreated bioconversion of cellulose-based microreactor

One‐Step Green‐Synthesized UiO‐66‐NH2 /Alginate Composite Hydrogels with Improved Methylene Blue Adsorption

AbstractZirconium‐based metal‐organic frameworks (Zr‐MOFs) represent an important class of MOFs with high stability and outstanding properties, the green preparation and shaping of which are still challengeable works to hinder their real‐world applications. In this presentation, UiO‐66‐NH2 MOFs were in‐situ grown accompanied by alginate (Alg) hydrogelation under aqueous conditions, achieving UiO‐66‐NH2/Alg composite hydrogels. Relevant characterizations demonstrate the in‐situ generated UiO‐66‐NH2 MOFs were evenly distributed in hydrogel networks by attaching on Alg fiber surfaces. The network structure became denser, but both specific surface area and pore volume were augmented due to the presence of MOFs, which in turn increased active sites to interact with adsorbates. Thus, the adsorption capacity to methylene blue (MB) of composite hydrogels became higher with more dosage of MOF ligand, and the pH sensitivity of Alg adsorption to MB in the pH range of 4 to 10 was eliminated. Furthermore, the study of adsorption kinetics and isotherm reveals MB adsorption on the obtained hydrogels belong to rate controlling chemisorption mechanism. In summary, this manuscript presents a facile approach to realizing the green synthesis and shaping of Zr‐MOFs by one‐step compositing of UiO‐66‐NH2 with Alg‐based hydrogels in aqueous system, achieving MOFs‐based composite hydrogels with enhanced MB adsorption.

Using Electrodeposition of Carboxylated Chitosan for Green Preparation of Copper Nanoclusters and Nanocomposite Films

Using Electrodeposition of Carboxylated Chitosan for Green Preparation of Copper Nanoclusters and Nanocomposite Films

Green preparation of carbon materials from biomass slag and steam as byproducts of power plants for efficient treatment of lead-containing wastewater

Green preparation of high-performance and cost-effective carbon materials using biomass slag and steam, which were the byproducts of power plants, for efficient treatment of lead (Pb(II))-containing wastewater was investigated. The optimum carbon material CH500-800 (SBET=818.8 m2/g and Vt=0.46 cm3/g) was produced by one-step steam activation at 800 ℃ for 1 h under a 500 mL/min stream with a heating rate of 5 °C/min. The obtained CH500-800 greatly enhanced the efficiency of Pb(II) removal, achieving the maximum adsorption capacity of 191.1 mg/g. The removal of Pb(II) from wastewater was well described by the Pseudo-second-order, Elovich and Freundlich model, suggesting that it was predominantly governed by chemical adsorption and diffusion on heterogeneous surfaces. The adsorption process demonstrated a synergistic mechanism involving pore and surface adsorption, chemical interactions between oxygen-containing groups (C-O and -OH) and Pb(II), as well as Pb(II)-π interactions, which was responsible for the efficient removal of Pb(II) from wastewater. Moreover, CH500-800 retained a potential for reusability with a high adsorption stability (only 2.5 % Pb(II) desorption after 48 h) and ion selectivity (>93.0 %) in the presence of K(I), Na(I) or Ca(II). Additionally, a circular economic model was proposed to valorize biomass slag and steam in situ for treating Pb(II)-containing wastewater effectively in biomass power plants. This approach provided an innovative solution for utilizing waste to treat hazardous substances within practical engineering applications.

Multifunctional molecular precursor with tunable nano-microarchitecture enables exceptional electromagnetic waves absorption

Multi-component carbon is a promising candidate for electromagnetic wave (EMW) absorption materials. However, complex and non-green preparation process with low atomic utilization efficiency compromises the merits of carbon materials. Additionally, enhancing the electromagnetic wave absorption (EMWA) is highly desirable. To face the challenge, a multifunctional molecular precursor (DQSDCI) has been developed, characterized by high atom utilization efficiency (high char yield), abundant in-situ nitrogen doping, multi-sites for composite of nano-materials (e.g. CNT) or metal ion (e.g. iron) and green preparation (water solubility). The multi-component carbons derived from DQSDCI, featuring adjustable nanostructures (nanoribbons or nanosheets) and modifiable porosity, demonstrate outstanding EMWA. The multicomponent carbon of DQSDCI, iron and CNT (DQSDCI-Fe-CNT-700) demonstrated a minimum reflection loss (RLmin) of −69.57 dB and a maximum effective absorption bandwidth (EABmax) of 5.7 GHz at about 2 mm thickness, covering a wide frequency range (4–18 GHz) by controlling the thickness between 1 and 5 mm. Moreover, simulation results indicated that the derived nanosheet is very promising application for aircraft stealth in a monostatic radar system. Abundant in-situ N doping, uniform distribution of MWCNT and ferromagnetic nanoparticles, hierarchical pore structures and various heterogeneous interfaces can synergistically improve the EMW attenuation ability by forming optimal impedance matching and multi-polarization loss.

The memory-improving effect of Hizikia forsiforme functional oil microcapsule (HFFOM) prepared by subcritical extraction and complex coacervational embedding

Functional foods are prospective in improving memory decline caused by Alzheimer’s disease and aging. The Edible seaweed Hizikia fusiforme functional oil (HFFO) inhibited acetylcholinesterase, prevented cellular neuroinflammation, and improved memory deficits in zebrafish models in the previous studies. To realize its greener preparation and lipid oxidation mitigation and study its effects on higher animals, more investigations are necessary. Herein, sub-critical fluid extraction of HFFO and successive complex coacervation embedding yielded a water-soluble and anti-oxidative microcapsule HFFOM, which displayed in vivo memory-improving effects on LPS-injured zebrafish and normal rodents in different behavior tests. HFFOM can elevate the level of the neurotransmitter acetylcholine while decreasing the levels of MDA, IL-1β, and TNF-α in the zebrafish brain. LC-MS/MS and lipidomic analysis suggested its predominant memory-improving ingredients to be linolenic, erucic, nervonic, arachidonic, linoleic, eicosatrienoic, docosahexaenoic, and docosapentaenoic acids. This study enlightens the potential of HFFOM in developing memory-enhancing functional foods or drugs.

Eutectic Strategy for the Solvent-Free Synthesis of Hydrophobic Cellulosic Cross-Linked Networks with Broad Multifunctional Applications.

Cellulose-based functional materials play a crucial role in sustainable social development. However, during the material synthesis process, there is typically significant reliance on various solvent systems for macroscopic- or molecular-scale functionalization modifications. In this study, an innovative hydrophobic eutectic solvent (HES) was developed using ethyl cellulose (EC) and thymol (Thy) without any external solvents. Utilizing this homogeneous system, it is convenient to chemically modify the components without any catalyst. Furthermore, a hydrophobic cellulosic cross-linked network (HCCN) can be successfully prepared through in situ photopolymerization. The HCCN film exhibits high transparency, excellent mechanical properties, chemical stability, and durability. The EC/Thy prepolymer system also demonstrates favorable processability for the preparation of various polymeric materials. Additionally, the applicability of other biomasses and derivatives based on the eutectic strategy has been verified. The methodology proposed in this study offers novel insights into the green and solvent-free preparation of biomass functional materials.

Two-Step Preparation of Asphalt-based Porous Carbon Adsorbent with Superior C2H6/CH4 Selectivity for Ethane Recovery from Natural Gas

Efficient recovery of ethane from natural gas is of industrial importance, yet it poses considerable challenges. Herein, we report the two-step green preparation of asphalt-based carbon adsorbent AsCs with exceptional C2H6/CH4 selectivity and high capacity, where the KOH usage can be significantly reduced by 75% than conventional chemical activation processes. More importantly, the resulting AsC-0.75-900 exhibits exceptional C2H6/CH4 separation performance with the IAST selectivity of 30.74 and ethane capacity of 4.53 mmol/g at 298 K and 100 kPa. Notably, even at the low pressure of 10 kPa, its ethane uptake remains high at 2.25 mmol/g, comparable to many advanced MOFs. Molecular simulation was used to elucidate the adsorption mechanism. Fixed-bed experiments further demonstrate dynamic separation performance, achieving complete separation of a C2H6/CH4 binary mixture (10:90, v/v) at ambient condition. In addition to its superior separation performance, AsC-0.75-900 offers inherent structural stability and cost-effectiveness, positioning it a highly promising candidate for ethane recovery from natural gas.

Cellulose acetate-decorated and siloxane-modified hydrophobic melamine foam with excellent selectivity and durability for efficient oil/water separation

The construction of hydrophobic porous adsorption materials, which are cost-effective, green, stable, and efficient, are urgently demanded for the large-scale and effective oily wastewater treatment. Herein, a facile and low-cost two-step fabrication strategy of hydrophobic melamine foam (MF) was demonstrated, including cellulose acetate (CA) decoration and siloxane modification. Cellulose acetate initially assembled on the skeleton of MF with the aid of hydrogen bond formation between the hydroxyl groups of CA and imimo groups of MF. At an optimal concentration of CA, the as-prepared composite foam (CA/MF) exhibited good hydrophobicity. To further improve the oil/water selectivity, the above foam was enhanced by chemical vapor deposition (CVD) of methyltrimethoxysilane (MTMS). The successful silicification reaction between CA/MF and MTMS decreased the surface energy and improved the surface topological structure, leading to excellent hydrophobicity (water contact angle of 147.4°) and superoliophilicty. Such hydrophobized cellulose acetate/melamine foam (H-CA/MF) presented low density, favorable porosity (97.78%), and distinguished pore volume (88.66 mL/g), leading to a high oil adsorption capacity of up to 56.6 g/g. Due to the excellent mechanical elasticity of H-CA/MF, the oil absorption and recovery can be achieved easily by a simple manual adsorption-squeezing method and lab-made pump-assisted separation device with satisfactory recyclability. Moreover, H-CA/MF displayed marvelous stability and environmental adaptability in different harsh environment, further enlarging its practical application scenarios. Along with the green and cost-effective preparation process, the present study provides a facile strategy to fabricate hydrophobized melamine-based foam, which is of great significance for scalable and efficient oil/water separation.

Green Biosynthesis and Catalytic Application in Environmental Pollutants of Functionalized Pd‐Ag Bimetallic Nanoparticle by Deinococcus Radiodurans Extracts

AbstractCatalytic reduction of organic pollutants using metal nanoparticles (MNPs) as nanocatalyst is a promising approach. The widespread application of MNPs have led to an increase demand for their production. The green biosynthesis of MNPs using microbes is becoming increasingly important as they are benign and environmentally friendly. In this work, Deinococcus wulumuqiensis (D. wulumuqiensis) with high resistance to stresses was applied for the green preparation of different MNPs, including palladium nanoparticles (Pd NPs), silver nanoparticles (Ag NPs), and Pd−Ag bimetallic nanoparticles (Pd−Ag BNPs). The resultant MNPs exhibited a face‐centered cubic structure, with average size of 6.70 (Pd NPs), 6.24 (Ag NPs), and 6.13 nm (Pd−Ag BNPs), respectively. FT‐IR spectra indicated that the proteins and polysaccharides expressed by D. wulumuqiensis could potentially contributed to the formation of MNPs. The application of as‐prepared biocatalyst in catalytic degradation of pollutant dyes demonstrated that Pd−Ag BNPs had greater degradation ability of 4‐nitrophenol (95.1 %) and Rhodamine B (85.1 %) than monometallic nanoparticles. The pseudo‐first‐order kinetics results further indicated the superior catalytic ability of Pd−Ag BNPs, with rate constant of 0.450±0.009 (4‐nitrophenol) and 1.54×10−2 min−1 (Rhodamine B), respectively. Thus, the present study confirms that D. wulumuqiensis represents a promising candidate for the biosynthesis of Pd‐based nanoparticles with small size, which exhibited potential applications as bionanocatalyst in the degradation of water pollutants.

An eco-friendly kapok fiber-supported liquid microextraction using natural deep eutectic solvent as extractant for convenient biological samples preparations: A proof-of-concept study

The use of natural materials and reagents is crucial for developing environmentally friendly methods. This study proposed an excellent green, convenient, cost-effective and rapid sample preparation method called kapok fiber-supported liquid-phase microextraction using natural deep eutectic solvent (KF-SLME-NADES). Natural kapok fiber and NADES were used as greener alternatives to conventional support medium and extractants. Low-toxic ethanol was employed as the desorption solvent. The extraction process was streamlined in a syringe form, allowing for simple pull-push operations. As a proof of concept, the developed methodology was utilized for extracting antidepressants from 3 mL of diluted biological fluids. The optimized KF-SLME-NADES conditions were obtained by single-factor experiments and Box-Behnken design as follows: 2 mg of kapok fiber, 13 μL of NADES composed of menthol and thymol in an equal molar ratio as the extractant, a sampling solution with a pH of 8.0, a desorption solution of 100 μL of ethanol, and four pull-push cycles for both extraction and elution. The validated method provided good linearity (0.05–5.00 μg/mL, R2 > 0.999) and possessed limits of quantification spanning from 0.025 to 0.048 μg/mL. Satisfied accuracies and precisions were obtained with relative recoveries ranging in 93.3–107.2% and intra- and inter-day RSD(%) being below 7.7%. The method greenness was found to be excellent by assessing five greenness evaluation metrics. The devised KF-SLME-NADES strategy provides a sustainable and effective method for bioanalysis.

N-doped carbon decorated by Cu3P nanoparticle derived from Aspartic acid - Cu MOF as suitable catalysts for oxygen and hydrogen evolution reactions

The preparation of high-efficiency electrocatalysts for the oxygen and hydrogen evolution process (OER and HER) using an easy, green, and facile preparation method is crucial for the effective and economical use of clean energy sources. We report here an eco-friendly phytic acid (PA)-assisted phosphidation strategy to synthesize a novel Cu3P decorated on N-doped carbon (Cu3P-NC). Its synthesis involves precipitation of rode-like microstructured Cu-based aspartic acid frameworks (Asp-Cu MOF), chemical etching of Asp-Cu MOF to form PA cross-linked Cu complexes, and a final pyrolysis step to get Cu3P-NC with abundant Cu3P nanoparticles loaded on N-doped carbon matrix. The Cu3P-NC catalyst demonstrates catalytic performances with low overpotentials of 116 and 310 mV at 10 mA cm−2, small Tafel slopes of 61.2 and 69.2 mV dec−1, for HER and OER respectively, and high catalytic durability in 1 M KOH. The as-prepared Cu3P-NC electrocatalyst offers a new viewpoint on developing multi-functional electrocatalysts in the water-splitting process using environment-friendly substances such as amino acids.

The tunable double-layer self-supporting Sb-Ni(OH)2 catalyst for boosting electrocatalytic water splitting

Green hydrogen preparation by electrolysis of water is key to driving the energy transition revolution. The development of low-cost, highly active and highly selective catalysts is a top priority for the commercial application from electrolytic water. This paper presents the synthesis of Sb-doped Ni(OH)2 nanosheets growing in situ on Ni foam, which serves as a self-supporting electrode. A straightforward one-step hydrothermal technique was employed to craft a dual-layer catalyst with a tunable morphology. Under the 1 M KOH conditions, Sb-Ni(OH)2-2.5/NF emerged as a bifunctional electrocatalyst, demonstrating an impressive HER performance of 159 mV (η10) and an OER performance of 430.8 mV (η50). The Sb-Ni(OH)2-2.5/NF also demonstrated remarkable stability by 3000 CV cycling tests. The Sb-Ni(OH)2-2.5/NF catalytic material prepared in this paper under laboratory conditions has a simple and inexpensive synthesis method, which helps to move electrolytic water catalysts from the laboratory to industry.

Comparative Study of Chemical and Green Preparation of Mesoporous Silica

يتضمن البحث الحالي دراسة مقارنة لتحضير السيليكا مسامية باستخدام طريقتين مختلفتين: الطريقة الكيميائية والطريقة الخضراء. تم استخدام طريقة sol-gel باستخدام سيليكات الصوديوم (الماء الزجاجي) كمصدر رخيص للسيليكا والمواد الخافضة للتوتر السطحي الكاتيونية في الطريقة الكيميائية، ومستخلص أوراق شجرة السدر بالطريقة الخضراء كقالب ناعم، وتمت مقارنة السيليكا المتوسطة المسام المحضرة باستخدام الطريقتين من خلال توصيفها باستخدام طرق مختلفة: قياس مساحة السطح بطريقة BET والمسامية بواسطة BJH، XRD، SAXRD، AFM، SEM و EDX أظهرت النتائج أن السيليكا المحضرة بالطريقة الخضراء حصلت على أفضل مساحة سطحية مسجلة 800 م2جرام-1 ومتوسط قطر مسام يساوي 2.5 نانومتر، بينما أظهرت قياسات حيود الأشعة السينية أن كلا الطريقتين أنتجتا سيليكا غير بلورية (غيرمتبلورة)، بينما أظهرت طريقة SAXRD أن الطريقة الخضراء أنتجت سيليكا أكثر انتظاما، وأظهرت دراسة الامتزاز أن السيليكا المحضرة كيميائيا لديها قدرة أعلى على امتزاز الأملوديبين وفقا لمعايير فروندليتش التي تم الحصول عليها عن طريق التركيب الخطي.

Facile and green preparation of carbonaceous material-based wood bio-adhesives using hydrochar from hydrothermal carbonization of glucose with or without acrylic acid/acrylamide

To address the issues of formaldehyde emission, mildew, and easy combustion of traditional wood adhesives, this paper, for the first time, reported formaldehyde-free plywood bio-adhesives using carbonaceous material (hydrochar) generated from hydrothermal carbonization (HTC) of glucose with or without acrylic acid (AA) and acrylamide (AM). The highest wet shear strength of bio-adhesives (BD-G/AA-180) was 1.32 MPa, which meets the Chinese national standard GB/T 9846-2015 (≥0.7 MPa). It was found that functional groups (–NH2 and –COOH) were abundant on the surface of hydrochar from co-HTC of glucose with AM or AA. The formation of covalent bonds (between components of bio-adhesives; between bio-adhesives and wood) via dehydration or esterification reaction was a key factor in improving wet shear strength during hot-press treatment. Unlike bio-adhesives developed from polysaccharides and proteins, these hydrochar carbonaceous material-derived bio-adhesives had excellent anti-mildew properties and flame resistance with help from ammonium polyphosphate. This work paves a new road to prepare green formaldehyde-free plywood bio-adhesives.

Ultrafast Synthesis of MXenes in Minutes via Low-Temperature Molten Salt Etching.

Developing green and efficient preparation strategies is a persistent pursuit in the field of 2D transition metal nitrides and/or carbides (MXenes). Traditional etching methods, such as HF-based or high-temperature Lewis-acid-molten-salt etching route, require harsher etching conditions and exhibit lower preparation efficiency with limited scalability, severely constraining their commercial production and practical application. Here, an ultrafast low-temperature molten salt (LTMS) etching method is presented for the large-scale synthesis of diverse MXenes within minutes by employing NH4HF2 as the etchant. The increased thermal motion and improved diffusion of molten NH4HF2 molecules significantly expedite the etching process of MAX phases, thus achieving the preparation of Ti3C2Tx MXene in just 5minutes. The universality of the LTMS method renders it a valuable approach for the rapid synthesis of various MXenes, including V4C3Tx, Nb4C3Tx, Mo2TiC2Tx, and Mo2CTx. The LTMS method is easy to scale up and can yield more than 100g Ti3C2Tx in a single reaction. The obtained LTMS-MXene exhibits excellent electrochemical performance for supercapacitors, evidently proving the effectiveness of the LTMS method. This work provides an ultrafast, universal, and scalable LTMS etching method for the large-scale commercial production of MXenes.

Application of Fabric Phase Sorptive Extraction as a Green Method for the Analysis of 10 Anti-Diabetic Drugs in Environmental Water Samples

Due to the increased prevalence of diabetes, the consumption of anti-diabetic drugs for its treatment has likewise increased. Metformin is an anti-diabetic drug that is commonly prescribed for patients with type 2 diabetes and has been frequently detected in surface water and wastewaters, thus representing an emerging contaminant. Metformin can be prescribed in combination with other classes of anti-diabetic drugs; however, these drugs are not sufficiently investigated in environmental samples. Fabric phase sorptive extraction (FPSE) has emerged as a simple and green method for the extraction of analytes in environmental samples. In this study, FPSE coupled with a high-performance liquid chromatography diode array detector (HPLC-DAD) was employed for the simultaneous analysis of different classes of anti-diabetic drugs (metformin, dapagliflozin, liraglutide, pioglitazone, gliclazide, glimepiride, glargine, repaglinide, sitagliptin, and vildagliptin) in environmental water samples. Four different fabric membranes were synthesized but the microfiber glass filter coated with sol-gel polyethylene glycol (PEG 300) was observed to be the best FPSE membrane. The parameters affecting the FPSE process were optimized using a combination of one-factor-at-a-time processes and the design of experiments. The FPSE was evaluated as a green extraction method, based on green sample preparation criteria. The FPSE-HPLC-DAD method achieved acceptable validation results and was applied for the simultaneous analysis of anti-diabetic drugs in surface and wastewater samples. Glimepiride was detected below the quantification limit in both lake and river water samples. Dapagliflozin, liraglutide, and glimepiride were detected at 69.0 ± 1.0 μg·L−1, 71.9 ± 0.4 μg·L−1, and 93.9 ± 1.3 μg·L−1, respectively, in the city wastewater influent. Dapagliflozin and glimepiride were still detected below the quantification limit in city wastewater effluent. For the hospital wastewater influent, metformin and glimepiride were detected at 1158 ± 21 μg·L−1 and 28 ± 0.8 μg·L−1, respectively, while only metformin (392.6 ± 7.7 μg·L−1) was detected in hospital wastewater effluent.

Facile green preparation of ZnFe2O4 nanoparticles using papaya leaf extract for electrochemical detection of acetaminophen in Zerodol P and Dolo drops

Facile green preparation of ZnFe2O4 nanoparticles using papaya leaf extract for electrochemical detection of acetaminophen in Zerodol P and Dolo drops