Photocatalytic degradation of methylene blue and antibacterial activity of mesoporous TiO2-SBA-15 nanocomposite based on rice husk

Concerns have been increased regarding the existence of pollutants in environmental water resources and their risks to the ecosystem and human society. TiO2 photocatalyst is considered as an effective photocatalyst to remove the pollutants. Herein, the mesoporous TiO2-SBA-15 was prepared using the rice husk extract as the silica source. The fabricated nanocomposites were characterized using FTIR, small and wide angle XRD, Raman spectroscopy, UV-vis, BET surface area analysis, and HRTEM. The photocatalytic efficiency of the composites for the degradation of methylene blue (MB) has been evaluated under UV irradiation. Interestingly, due to the excellent dispersion of TiO2 on the wall of SBA-15 and good hydrophilicity, the nanocomposites displayed a good catalytic activity. The higher photodegradation performance was achieved by the composite containing 10 wt% TiO2 by which the MB was fully degraded within 15-20 min of irradiation. Besides, TiO2-SBA-15 could effectively inhibit the growth of Gram-positive and Gram-negative bacteria. These results offer a practical and economic approach in the environmental management industries

High-Pressure Metal-Free Catalyzed One-Pot Two-Component Synthetic Approach for New 5-Arylazopyrazolo[3,4-b]Pyridine Derivatives

An appropriate and efficient Q-tube-assisted ammonium acetate-mediated protocol for the assembly of the hitherto unreported 5-arylazopyrazolo[3,4-b]pyridines was demonstrated. This methodology comprises the cyclocondensation reaction of 5-amino-2-phenyl-4H-pyrazol-3-one with an assortment of arylhydrazonals in an NH$_4$OAc/AcOH buffer solution operating a Q-tube reactor. This versatile protocol exhibited several outstanding merits: easy work-up, mild conditions, scalability, broad substrate scope, safety (the Q-tube kit is simply for pressing and sealing), and a high atom economy. Consequently, performing such reactions under elevated pressures and utilizing the Q-tube reactor seemed preferable for achieving the required products in comparison to the conventional conditions. Diverse spectroscopic methods and X-ray single-crystal techniques were applied to confirm the proposed structure of the targeted compounds

Hybrid PSf/TNT-SO3H Ultrafiltration Membrane Fouling by Sodium Alginate: Effect of Permeation Flux on Fouling Resistance and Desalination Efficiency

The development of low fouling UF membranes with boosting water flux for implementations in water purifications is critical. Organic foulants and ionic strength are the main characteristics of surface water which affect the membrane performance for water generation and seawater desalination. Low fouling hybrid ultrafiltration membranes were fabricated from a combination of sulfonic acid functionalized titanium nanotubes (TNTs-SO3H) and polysulfone (PSf) by the nonsolvent-induced phase separation approach. The membrane fouling was explored utilizing a polysaccharide sodium alginate (SA) as a hydrophilic nature organic matter, and the impact of Na+ and Ca2+ ions on alginate membrane fouling were also addressed. The results showed that the membranes’ water permeability and natural organic matter fouling resistances were affected by the proportion of TNTs-SO3H in the membranes. The inclusion of TNTs-SO3H improves the water penetration fluxes (Jw1) and surface hydrophilicity of the manufactured membranes. In the UF of sodium alginate solution, the produced membrane comprising 5% TNTs-SO3H exhibits a higher penetration flux and rejection value than the other membranes. The introduction of Na+ and Ca2+ ions to the SA solution reduces the membrane fouling. Furthermore, the adsorption investigation of sodium alginate solutions at pH=7 was lowered as the amount of TNTs-SO3H was increased. After ultrafiltration, the fouled membrane containing 5% TNTs-SO3H is readily removed, and recurrent antifouling experiments indicate a consistent and maximum filtration efficiency

Highly efficient ultrafiltration membrane performance of PES@microcrystalline cellulose extracted from waste fruits for the removal of BrO3- from drinking water samples

New mixed-matrix ultrafiltration membranes (MMMs) made of polyethersulfone (PES) and microcrystalline cellulose (MCC) were created utilizing a nonsolvent induced phase separation (NIPS) approach for the remediation of bromate (BrO3-) from aqueous medium. The influence of MCC integrated on the contact angle, porosity, water flux, and BrO3- adsorption performance was also examined. The addition of MCC, up to 5 wt%, resulted in a significant decline in the contact angle from 60.1° of neat PES to 43.1°, indicating an increase in membrane hydrophilicity. Moreover, MCC incorporation at 1, 3, and 5 wt% concentrations led to an enhancement in the water flux to 169, 178, and 180 L m-2 h-1, respectively, indicating the improved membrane permeability. MCC-integrated PES membranes exhibited enhanced antifouling properties, as demonstrated by the achieved high flux recovery ratio (99%) of the 5% MCC-containing membrane. Furthermore, all MCC-integrated PES membranes exhibited superior performance in the removal of bromate ions (BrO3-), with rejection rates of 60.8%, 80.2%, and 92% for 1%, 3%, and 5% MCC, respectively, which was much greater than that of the virgin PES membrane

Antifouling hybrid ultrafiltration membranes with high selectivity fabricated from polysulfone and sulfonic acid functionalized TiO2 nanotubes

[Display omitted] •Hybrid UF membranes were prepared using PSf and sulfonic acid functionalized TiO2 nanotubes.•Hydrophilicity, charge and morphology of membranes depended on loading amount of TNTs-SO3H.•Hybrid membranes displayed excellent antifouling and selectivity at up to 5wt% TNTs-SO3H.•Membranes were effective at removal of humic acid up to 50ppm from aqueous solution at pH 7. In this work, antifouling hybrid ultrafiltration membranes were manufactured using polysulfone (PSf) and sulfonic acid functionalized TiO2 nanotubes (TNTs-SO3H). TNTs-SO3H were first synthesized by performing a coupling reaction between 3-mercaptopropyl trimethoxysilane and hydroxyl groups on TiO2 nanotubes with in situ oxidation using 30wt% H2O2 solution. Hybrid membranes containing TNTs-SO3H up to 5wt% were then prepared from the blend solutions of PSf/TNTs-SO3H via a non-solvent induced phase separation (NIPS) method. The hybrid membranes were characterized using contact angle, Fourier transform infrared spectroscopy, scanning electron microscopy and surface zeta potential studies. The antifouling capability of hybrid membranes with bovine serum albumin and humic acid (HA) as model foulants were investigated in detail. Hybrid membranes exhibited better water permeability and antifouling performance during filtration of foulant solutions. The ultrafiltration of HA solutions of different concentrations was carried out at pH=7 and 1bar feed pressure, with the removal of HA from aqueous solution being controlled through the charged behaviour, porosity and exclusion of HA by hybrid membranes. The maximum removal of HA from 20ppm aqueous solution was achieved using the hybrid membrane MTS-5 containing 5wt% TNTs-SO3H

Biogenic-Mediated Synthesis of Mesoporous Cu2O/CuO Nano-Architectures of Superior Catalytic Reductive towards Nitroaromatics

Cu2O/CuO nano-architectures were prepared by biogenic-mediated synthesis using pomegranate seeds extract as the reducing/stabilizing mediator during an aqueous solution combustion process of the Cu2+ precursor. The fabricated Cu2O/CuO nanocomposite were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FESEM) and nitrogen sorption. Nitrobenzene (NB) was applied a probe to test the catalytic activities of the fabricated Cu2O/CuO nanocomposite. The results indicated that pomegranate seeds extract (PSE) manifest Cu2O/CuO NPs of tiny particle size, larger pore volume and greater surface area compared to the bulky CuO synthesized in the absence of PSE. The surface area and total pore volume of Cu2O/CuO NPs were 20.1 m2 g−1 and 0.0362 cm3 g−1, respectively. The FESEM image shows the formation of broccoli-like architecture. The fabricated Cu2O/CuO nanocomposite possesses surprising activity towards the reduction of nitro compounds in the presence of NaBH4 into amino compounds with high conversion (94%). The reduction process was performed in water as a green solvent. Over four consecutive cycles the resulting nanocomposite also exhibits outstanding stability. In addition, the resulting Cu2O/CuO nanocomposite suggested herein may encourage scientists to start preparing more cost-effective catalysts for marketing instead of complicated catalysts

Towards superior permeability and antifouling performance of sulfonated polyethersulfone ultrafiltration membranes modified with sulfopropyl methacrylate functionalized SBA-15

A non-solvent induced phase separation (NIPS) process was used to fabricate a series of sulfonated polyethersulfone (SPES) membranes blending with different concentrations of SBA-15-g-PSPA with the applications in the ultrafiltration (UF) process. SBA-15 was modified with 3-methacrylate-propyltrimethoxysilane (MPS) to form SBA-15-g-MPS. It was further modified with the charge tailorable polymer chains by reacting with 3-sulfopropyl methacrylate potassium salt. The nanoparticles were uniformly dispersed and finger-like channels were developed within the membrane. The adding of surface modified SBA-15-g-PSPA nanoparticles has significantly improved membrane water permeability, hydrophilicity, and antifouling properties. The pure water fluxes of the composite SPES membranes were significantly higher than the pristine SPES membrane. For the membrane containing 5% (mass) of SBA-15-g-PSPA (MSSPA5), the pure water flux was increased dramatically to 402.15 L·m−2·h−1, which is ∼1.5 times that of MSSPA0 (268.0 L·m−2·h−1). The high flux rate was achieved with 3% (mass) of SBA-15 nanoparticles with retained high rejection ratio 98% for natural organic matter. The results indicate that the fashioned composite membrane comprising SBA-15-g-PSPA nanoparticles have a promising future in ultrafiltration applications

Synthesis, characterization of PMDA/TMSPEDA hybrid nano-composite and its applications as an adsorbent for the removal of bivalent heavy metals ions

[Display omitted] •HPNC was synthesized by ring opening polymerization and sol–gel reaction.•Hydrated radius and electronegativity played significant role in metal adsorption.•Metal ions interaction with –NH active sites was a possible adsorption mechanism.•Elution was maximum (Pb(II) 94.13%>Zn(II) 93.59%>Cd(II) 84.15%) with 0.1M HCl.•28.99% and 16.96% loss in Pb(II) adsorption and recovery after four consecutive cycles. Novel PMDA/TMSPEDA hybrid polymeric nano-composite (HPNC) was synthesized by ring opening polymerization and sol–gel reaction. TGA analysis showed thermally stable polymeric material. FT-IR analysis revealed co-ordinate bonding between amine groups (present on HPNC) and bivalent metal ions as a possible adsorption mechanism. Adsorption studies showed maximum uptake of Pb(II) (49.72mg/g) on HPNC followed by Cd(II) (45.22mg/g), and Zn(II) (41.75mg/g) at pH 7. Thermodynamically, the process was exothermic. Freundlich and pseudo-second-order kinetics model were the best fitted models to the experimental data. Kinetics studies showed better performance of HPNC for Cd(II) at lower concentration while Pb(II) adsorption was highly favorable at higher concentration. Rapid adsorption kinetics was observed for Pb(II) with equilibration time at various concentrations varied between 10 and 30min. Desorption studies showed maximum metal elution [Pb(II) (94.13%)>Zn(II) (93.59%)>Cd(II) (84.15%)] with 0.1M HCl. Regeneration studies showed 28.99% and 16.96% loss in Pb(II) adsorption and recovery after four consecutive cycles, respectively. The findings of present study showed potentiality of HPNC as an effective and economically feasible adsorbent for Pb(II)