Journal of Saudi Chemical Society最新文献

The valorization of biogenic waste by hydrothermal carbonization is widely discussed in research. However, to our knowledge, no study has combined almond shells and olive pomace to synthesize a solid carbon material. The purpose of this study is to enhance the hydrochar process from AS and OP using RSM methodology and machine learning models: ANN, SVM and XG-Boost. Subsequently, a study was carried out on the removal of organic pollutants by the synthesized material. The optimum Co-HTC operating conditions obtained at 180 C, 90 min with acid catalyst corresponding to 71.51 % and 87.13 % for mass yield and carbon retention rate respectively according to RSM-CCD. The comparison between RSM-CCD and ML in terms of prediction concludes that RSM remains more efficient in terms of planning and optimization. However, ANN is more suitable for modeling and predicting mass yields and carbon retention rates. Hydrochar’s physicochemical properties were evaluated by the use of spectroscopic methods like FTIR, SEM, XRD, and CHNO. To conclude, we studied the performance of HCop in methylene blue adsorption, varying the following parameters: pH, contact time, initial dye concentration, adsorbent dose and temperature. In addition, kinetic and isothermal models were studied to describe the dominant mechanisms in the MB adsorption process. The MB maximal adsorption using HCop obtained at pH 9, with an initial dye concentration of 100 mg. L⁻¹, 40-min contact time, 0.1 g/L adsorbent dose, and a temperature between 25 and 30 °C. In conclusion, these results provide important information on the use of Co-HTC to convert biogenic wastes into high-performance carbon materials for the appropriate removal of organic pollutants. More studies are needed to use the material in other fields of application.

One of the most important ways to practice environmental stewardship is to turn waste materials into useful nanomaterials through ecological recycling. This work introduces a magnetic organocatalyst made from red mud waste, adding to the “greening” of global chemical processes.

The new composite (Fe₃O₄@SiO₂@(CH₂)₃@4-(2-Aminoethyl)-morpholine) is introduced and characterized by different spectroscopic methods such as fourier transform infrared (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), mapping, thermogravimetric analysis (TGA) and vibrating-sample magnetometers (VSM). Catalytic activity of the catalyst was evaluated in production of some polyhydroquinoline derivatives and the results showed efficiency. Nine polyhydroquinoline derivatives were synthesized (M₁-M₉) and their cytotoxic properties evaluated against two human-cancerous cell lines (Hep-G2 and SW480) by MTT assay. Most of the compounds exhibited high inhibitory activity against two studied cell lines. M₂ bearing 2-chloro substitution on phenyl ring was exhibited appropriate activity (IC₅₀ = 14.70 ± 3.11 µM) against SW480 cell line in comparison to cisplatin as positive control.

Bismuth based MOFs have appealed much curiosity in different catalytic processes due to their remarkable properties, which include their porous structure, less toxicity, abundance and high specific surface area. With their distributed active sites and constrained reaction regions, Bi based MOFs have a bright future as catalysts for extremely focused CO₂ reduction by electrocatalysis reactions (ECO₂RR). Formic acid (HCOOH), one of the byproducts of these processes, is notable because of its high economic worth. An extensive summary of Bi-MOFs and their derivatives used in ECO₂RR and the photocatalytic reduction of CO₂ into useful compounds is given in this review. Bi-MOFs synthesis methods for both electro and photocatalyst applications are discussed, along with an analysis of their unique benefits. Interestingly, a variety of Bi-MOFs and related offshoots are highlighted, including bimetallic catalysts and Bi-based MOF-derived nanocomposites. Bi-MOFs catalysts’ catalytic efficacy is demonstrated to be closely related to the MOF structure blocks-metal ions and organic linkers as well as particular circumstances controlling their derivatization. As a result, Bi-MOFs catalysts have a wide range of functions and provide the possibility of controlling the catalytic performance. This review describes the current obstacles in this area and makes recommendations for future research paths to advance the use of Bi-MOFs as electro- and photocatalysts.

In this study, the waste newspaper was utilized to prepare carbon aerogel (CA) for adsorptive removal of Metformin hydrochloride (MH) (antidiabetic drug residues) from the aqueous system. The prepared CA was characterized using Field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), and Brunauer-Emmett-Teller (BET) analyser. The MH adsorption was carried out using two types of water, one was laboratory-prepared distilled water and another was real river water. Although, optimum removal around 87 % was observed at pH 3, the removal efficiency at about 63 % estimated at neutral pH. In river water experiment, slightly lower rate of adsorption about 59 % was noticed. Nearly 61 % removal was found for 120 min and then no significant adsorption was found. The pseudo-second-order kinetics and Freundlich isotherm models presented a good interpretation of the adsorption experiment data. Physio-sorption was the primary mechanism of the MH adsorption was confirmed by Temkin and D-R isotherms studies. Regeneration studies demonstrated the removal stability of CA around 32 % until five cycles. An adsorption mechanism was also proposed for the removal of metformin hydrochloride using carbon aerogel.

The advancement of reverse osmosis (RO) technology in water treatment has brought about significant purification benefits. However, the presence of scales poses obstacles to the long-term effectiveness and reliability of RO systems, therefore, the use of antiscalants has emerged as an effective solution. This comprehensive review explores various aspects of scale formations, including their characteristics and prevalence. It delves into detailed understanding of crystal nucleation inhibition, dispersion of crystal growth, threshold inhibition, and inhibition mechanisms, shedding light on the intricate processes involved in successful scale prevention. In addition, this review also explores the realm of antiscalants, uncovering their exceptional potential, mechanisms of action, and game-changing value in RO systems. It takes a thorough evaluation approach to different antiscalant substances, ranging from traditional inhibitors like phosphonates and synthetic polymers to more sustainable and greener inhibitors including biopolymers as promising candidates. The review assesses their efficacy, optimal dosage requirements, and compatibility with varying water pH levels. Moreover, the review highlights the utility of fluorescent-labeled antiscalants to elucidate the mechanisms underlying scale formation and inhibition, revealing the role of “nanodust” particles as primary heterogeneous nucleation centers, and the antiscalants’ role in disrupting the scale formation process. Limitations of current antiscalants and practical challenges, such as antiscalant-induced membrane biofouling, are also highlighted. Furthermore, the review explores options for removing antiscalants from the resulting concentrates. By setting the stage for future antiscalant research, this review offers innovative solutions to overcome existing challenges and achieve higher efficiency in RO systems, emphasizing the important role of synthetic and green polymers as antiscalants.

In this study, silver nanoparticles (AgNPs) were synthesized by utilizing different volumes of silver nitrate (AgNO₃) and a medicinally important protein, bovine serum albumin (BSA); subsequently, their anticancer and antibacterial activities were investigated. The volume of AgNO₃ and BSA were varied to obtain physically and chemically stable NPs for better therapeutic effects. The synthesized BSA@AgNPs were characterized by spectroscopic and microscopic methods, such as FTIR, and UV–Vis spectroscopy, SEM/EDS, and TEM/SAED. The characterization results offer substantial proof for the successful preparation of non-aggregated stable BSA@AgNPs. The EDS analysis revealed the presence of Ag, C, and O, thus reaffirming the preparation of BSA-conjugated AgNPs. The anticancer efficacy of BSA@AgNPs was studied against colorectal (HCT-116) and HeLa cancerous cell lines. The anticancer results showed that the treatment of cancer cells with BSA@AgNPs decreased the number of cells compared with untreated cells. The NPs prepared with a moderate amount of BSA showed a better inhibiting property than the particles prepared with a high amount of BSA. The antibacterial activity of BSA@AgNPs was studied against gram-positive (S. aureus) and gram-negative (E. coli) bacteria. SEM and TEM analyses confirmed that S. aureus and E. coli cells were damaged upon exposure to BSA@AgNPs in the form of deep pits and cavities as opposed to untreated cells. The obtained results show that the green synthesized BSA@AgNPs could be used as potential anticancer and antibacterial drugs.

The development of novel and environmentally friendly solvents for chemical reactions is a vital in the pursuit of sustainable chemistry. This study presents a sustainable and efficient protocol for the rapid oxidation of benzaldehyde derivatives in the presence of catalytic Deep Eutectic Solvent (DES) system to their corresponding benzoic acids. A novel ternary DES composed of Urea/ZnCl₂/HCl was synthesized using a combination of Urea, ZnCl₂, and HCl for the first time and employed as an environmentally friendly oxidation catalyst using H₂O₂ as an oxidant at 60 °C. Benzaldehyde derivatives with diverse range of functional groups and substitution patterns afforded remarkable results, as it achieved high to excellent yields of the corresponding benzoic acids within a remarkably short reaction time of only 50 min. This protocol offers several advantages over alternative methods, including high product yields, the elimination of toxic and hazardous solvents and catalysts, and straightforward experimental procedures. Furthermore, the synthesized DES excellent recyclability, allowing for its reuse up to five times without any significant loss of functionality. Moreover, the synthesized DES demonstrated exceptional recyclability, enabling it to be reused up to five times without experiencing any notable decline in its effectiveness or functionality.

In this study, we presents a novel method for bolstering the photocatalytic effectiveness of crystalline titanium dioxide (TiO₂) through the integration of graphitic carbon nitride (g-C₃N₄), creating a series of TiO₂/g-C₃N₄ nanohybrids (TiCN-NHs). Leveraging an economical and scalable pyrolysis technique, we crafted different ratios of these nanohybrids (TiCN-NHs-1, TiCN-NHs-2, TiCN-NHs-3, and TiCN-NHs-4) to optimize their performance in harnessing visible light for photocatalysis. Detailed spectroscopic examinations were performed to dissect the nanohybrids’ structural and morphological nuances, alongside their chemical interactions and states. The primary evaluation of these nanohybrids’ photocatalytic prowess was the degradation of a selected colored organic contaminant under visible light exposure. The TiCN-NHs showcased an unprecedented photocatalytic degradation efficiency, surpassing that of p-TiO₂ and bulk b-g-C₃N₄ by twelvefold and eightfold, respectively, under comparable conditions. This dramatic increase in photocatalytic activity is credited to the harmonious interface between TiO₂ and g-C₃N₄ within the nanohybrids, fostering a diminished bandgap and promoting efficient charge separation. Additionally, photoluminescence and density of state analyses, specifically focusing on valence band spectra under visible light irradiation, further confirmed these findings. The synergistic effects observed in TiCN-NHs not only enhance photocatalytic degradation rates but also spotlight the potential of these nanohybrids in solar energy conversion and environmental cleanup applications, offering a promising avenue for future research in sustainable technologies.

Facilitating the separation of photogenerated charges is a crucial process in photocatalytic degradation of pollutants. In this study, Bi₂O₃/In₂O₃ composites were prepared using a co-precipitation method and subsequently calcined at 400 ℃ for 1 h. The Mott-Schottky curves confirmed a p(Bi₂O₃)-n(In₂O₃) heterojunction was yielded. Due to the significant difference in Fermi levels between Bi₂O₃ and In₂O₃, an internal electric field was established at the interface, with field lines directed from In₂O₃ to Bi₂O₃. Under illumination, the excited electrons accumulated in the conduction band (CB) of In₂O₃, while holes gathered in the valence band (VB) of Bi₂O₃, promoting charge separation and enhancing quantum efficiency. The composite material exhibited the highest photocatalytic activity when the atomic percentage of Bi to In was 1:1, with the first-order reaction rate constant of BI-1 increasing to 0.0149 min⁻¹, which is 4.3 and 4.4 multiples higher than that of pure In₂O₃ and pure Bi₂O₃. Recycling experiments demonstrated that the photocatalytic composite possesses good reusability and structural stability.

Modified phosphogypsum (PG) was prepared via low-temperature thermal decomposition to remove fluoride ions from wastewater. This study discussed the effect of heat treatment (pyrolysis temperature and time) and operating conditions (initial fluoride ions concentration, dosage, solution temperature, and initial pH) on fluoride ions removal efficiency. The results showed that PG was most successful in removing fluoride at 140 ℃ for 5 h. At an initial fluoride ions concentration of 100 mg/L, a dosage of 10 g/L, a solution temperature of 20 ℃, and strongly acidic (pH=2) and neutral (pH=7) environments, the fluoride removal efficiency of the PG reached 93.9 % and 66.7 %, respectively. In addition, when the initial fluoride ion concentration was reduced (25 mg/L), the heat-treated modified PG exhibited inadequate fluoride removal (<40 %). Increasing the solution temperature and initial pH was not conducive to fluoride ions removal. SEM-EDS, TG-DTG, FTIR, XRD and XPS analyses showed that thermal decomposition at a low temperature transformed the calcium sulfate dihydrate (CaSO₄·2H₂O) in the PG into calcium sulfate hemihydrate (CaSO₄·0.5H₂O) with higher solubility, increasing the Ca²⁺ ions concentration in the solution and further removing the F^- ions via chemical precipitation. Quantitative X-ray diffraction (QXRD) analysis revealed that the concentration of CaSO₄·0.5H₂O in PG is highest when subjected to optimal heat treatment conditions (140 ℃ for 5 h). Therefore, simple low-temperature thermal decomposition treatment (140 ℃) reduced PG energy consumption and effectively removed fluoride ions from wastewater, achieving the purpose of “ waste-treating-waste”.