Journal of Saudi Chemical Society最新文献

Sulfamethoxazole (SMX) is an extensively applied antibacterial drug, and it is also a pollutant that poses a serious threat to human and ecosystem health. In this research, a 3D hierarchical hollow ball-flower structure catalyst (CoAl-LDHs@CoS_x-rGO) was tailored for the first time to efficiently degrade SMX via visible light coupling PMS activation. A series of characterizations confirm that the target catalyst is successfully prepared and the optimized 0.1CoAl-LDHs@CoS_x-rGO sample possesses superior specific surface area of 306.0 m²/g, and significantly higher photocurrent response and lower electrochemical impedance. More importantly, 0.5 g/L of the sample can degrade 98.59 % of SMX within 50 min via visible light coupling PMS activation, and after 7 degradation cycles, the degradation rate only decreased by 8.49 %. A series of parameters that affect degradation rate have been optimized in detail. Capture experiments and ESR indicate that e⁻, •OH and SO₄^•− make major contributions to degradation, and visible light coupling PMS activation generates stronger signals than alone visible-light or PMS system. LC-MS, TEST toxicity assessment and theoretical calculation were conducted to elucidate degradation route and intermediate toxicity. The research provides a new approach to design catalysts with highly exposed activity sites for efficiently removing SMX from environmental water.

Antibiotic contamination is a global environmental problem. The emerging contaminant norfloxacin (NOR) may increase the risk of drug resistance and thereby harm human health. The practical application of metal–organic framework crystals is usually limited by their powder form and difficulty in recovery. In this study, a magnetic Co-MPS-800 composite was prepared from carbonization with ZIF-67@pine sawdust, and significantly raised the NOR removing ability from wastewater. The changes in functional group composition, elemental contents, morphology, thermal stability and adsorption mechanism of the magnetic Co-MPS-800 composite were interpreted using FT-IR, XRD, SEM, BET, TGA and XPS. The Co-MPS-800 has an isoelectric point of 9.15 and a large specific surface area (174.58 m²·g⁻¹). The impacts of pH, contact time, temperature and dosage on the performance of Co-MPS-800 were also studied. The adsorption capacity over NOR reached 221.98 mg·g⁻¹ at 303 K, pH=6.0. The NOR adsorption is best suited a pseudo-2nd-order kinetic model and the Freundlich isotherm. Co-MPS-800 also had excellent reusability, and the removal rate reached 82.94 % after four repeated uses. Therefore, the magnetic Co-MPS-800 composite is effective in removing NOR from aqueous solutions. Altogether, this functional MOF-derived porous carbon may serve as a promising pollutant biosorbent, and its preparation strategy may provide insights for future studies.

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, 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.

With the rapid development of global digital economy and aerospace, the gap between the supply and demand of germanium is expanding, and the establishment of a new process for the deep leaching of germanium from hard zinc slag is imminent. In this paper, on the basis of analyzing the reasons for the low germanium leaching rate from hard zinc slag, a new process of germanium leaching enhanced by HNO₃ dissolution of externally wrapped ZnFe₂O₄ is established, and response surface optimization is carried out. The PbggGe₄O₇ phase in hard zinc slag is externally wrapped with ZnFe₂O₄ phase, and the non-reaction between ZnFe₂O₄ and hydrochloric acid is the main reason for the low leaching rate of germanium from hard zinc slag, so it is necessary to add HNO₃ to dissolve the external ZnFe₂O₄ in leaching, and then use hydrochloric acid to leach the PbGe₄O₇ containing germanium in the interior. The potential pH diagram of the Pb-Ge-Cl-H₂O system was also plotted, indicating that increasing the concentration of chloride ions during hydrochloric acid leaching contributes to the generation of GeCl₄ at low acidity. When the hydrochloric acid concentration was 134.65 g/L, the liquid–solid ratio was 6, the theoretical dosage of HNO₃ was 0.3, and the leaching time was 236 min, the optimum leaching rate of germanium was 93.72%, which was 23.72% higher than that of germanium leaching from hard zinc slag.

Urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) are the key processes for implementing urinated water electrolysis and hydrogen green production, respectively. This contribution investigates the modification of commercial nickel foam (NF) with a nickel phosphate (NiPO/NF) heterostructure layer via anodizing in phosphate solution at various potentials (5, 10 and 15 V) as a simple and efficient route to boost the urea-assisted water electrolysis and hydrogen production in alkaline medium. The morphology and composition physicochemical characterisation of the phosphate layer exhibit aggregates of crystalline nanoparticles with interstitial mesoporous and macroporous networks with a mole composition ratio of 9.42: 1.0: 8.14 for Ni: P: O respectively. The electrochemical measurements revealed the NiPO/NF anodized at 10 V exhibits a superior electroactive surface area of 255 cm², a substantially higher urea oxidation current compared to pristine NF, achieving 20 and 500 mA/cm² at 1.35 and 1.6 V vs. RHE respectively and retained 100 % of activity during the urea electrolysis for more than 3 h. The electrochemical impedance analysis confirmed the alkaline urea oxidation reaction proceeded via indirect (EC) and direct mechanism and the CO₂ intermediates adsorption–desorption became the predominant reaction at more positive potential. The NiPO/NF anode employed in an H-shape can deliver up to ±400 mA/cm² for UOR/HER at a bias potential of 1.85 V and 8-fold (2.0 mmol/min) much higher hydrogen production rate compared to the pristine NF anode (0.25 mmol/min). Combining commercial nickel foam modification via anodizing and alkaline urea electrolysis at ambient conditions offers a unique and innovative solution for both large-scale hydrogen green production as well as remedy of the urinated wastewater for a more sustainable future.