The remarkable characteristics of graphene make it a model candidate for boosting the effectiveness of nano-adsorbents with high potential owing to its large surface area, π–π interaction, and accessible functional groups that interact with an adsorbate. However, the stacking of graphene reduces its influence adsorption characteristics and also its practical application. On the other hand, the widespread use of aromatic compounds in the industry has aggravated the contamination of the water environment, and how to effectively remove them has become a research hotspot. Herein, we develop the functionalization of silica nanoparticles on graphene oxide nanosheet (FGS) by a facile, cheap, and efficient synthesis protocol for adsorption of Trypan Blue (TB) and Bisphenol A (BPA). It was demonstrated that chemical activation with KOH at high autoclaving temperature successfully transformed rice husk ash (RHA) into FGS. The graphene oxide layered interlamination was kept open by using SiO2 to expose the interlayers' strong adsorption sites. XRD, EDX, FTIR, Raman spectroscopy, SEM, HR-TEM, and BET surface area are used to investigate the chemical composition, structure, morphology, and textural nature of the as-produced FGS hybrid nanocomposite. The various oxygen-containing functional groups of the hybrid nanocomposites resulted in a significantly increased adsorption capacity, according to experimental findings. In addition, FGS2, the best composite, has a specific surface area of 1768 m2g−1. Based on Langmuir isotherms, the maximal TB dye and BPA removal capacity attained after 30 min were 455 and 500 mg/g, respectively. The Langmuir isotherm model, a pseudo-second-order kinetic model, and an intraparticle diffusion model have all been used to provide mechanistic insights into the adsorption process. This suggests that BPA and TB adsorption on FGS2 is mostly chemically regulated monolayer adsorption. Due to its unique sp2-hybridized single-atom-layer structure, the exposed graphene oxide nanosheets' extremely hydrophobic effect, hydrogen bonding, and strong—electron donor–acceptor interaction contributed to their improved adsorption of BPA and TB. According to adsorption thermodynamics, FGS2 adsorption of TB and BPA is a spontaneous exothermic reaction that is aided by lowering the temperature. For adsorption-based wastewater cleanup, the produced nanocomposites with a regulated amount of carbon and silica in the form of graphene oxide and silica can be used. These findings suggest that functionalized GO/SiO2 hybrid nanocomposites could be a viable sorbent for the efficient and cost-effective removal of aromatic chemicals from wastewater.

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Reverse osmosis (RO) is considered a lifesaver technology to conquer the current catastrophic water shortage situation. However, reaching a competitive RO membrane is a challenging issue. Therefore, this study investigated the optimum polymeric blending ratio between cellulose acetate (CA) and polyvinylidene fluoride (PVDF) to have a new blended polymeric membrane named cellulose acetate polyvinyl (CAPV-X), where X is the PVDF concentration %, with enhanced properties. The optimum prepared CA/PVDF blended membrane was selected for further enhancement with nano sized metal organic framework (UiO-66 MOF). Selection was made depending on each membrane salt rejection. A membrane characterization was performed based on Fourier transform infrared (FTIR), X-ray diffractometer (XRD), scanning electron microscope, thermal gravimetric analysis, and contact angle. FTIR and XRD data confirmed the successful preparation of the blended polymeric membranes CAPV-5, CAPV-7 and CAPV-10. Further, they proved UiO-66 nanofiller impregnation in the hybrid CA/PVDF/UiO-66 membrane (CPU). The addition of PVDF and nano-MOF had a slight positive effect on the membrane thermal stability. The contact angle increased with increasing the PVDF concentration and decreased once more with the impregnation of UiO-66. The RO membrane performance revealed that the optimum CA/PVDF ratio was found to be 93/7% with around 80% salt rejection and a permeate water flux of 4 L/m2 h. CPU composite membrane was then fabricated to enhance salt rejection and permeate water flux. The testing data indicated that salt rejection and permeate water flux increased over blended CAPV-7 membrane by almost 12% and 42%, respectively. Overall, CPU hybrid membrane could be used for water desalination with a good salt rejection of 90.2% and a permeate water flux of 5.7 L/m2 h. Graphical abstract

Photocatalysis is a green approach that has appeared to be a viable option for the degradation of a variety of organic contaminants. This work outlines the process of preparing the titanium-based metal-organic framework (MIL-125) photocatalysts using a simple solvothermal method. Structural, morphological, and optical analysis of samples (MT18 and MT48) was carried out by XRD, FT-IR, Raman, SEM, TGA, BET, and UV–Vis. Results indicated that the sample prepared at 150 °C and reaction time of 48 h (MT48) has a low crystal size of 7 nm with an optical band gap of 3.2 eV and a surface area of 301 m2 g−1. Under UV–visible light irradiation, the as-prepared MOFs proved to upgrade photocatalytic activity in degrading crude oil spills in saltwater. Effects of catalyst dosage and exposure time on the degradation of an oil spill in seawater were studied and analyzed using UV–Vis spectrophotometry and gas chromatography (GC–MS) which emphasized that the use of 250 ppm of MT48 photocatalyst under UV–Vis irradiation can degrade about 99% of oil spills in water after 2 h of exposure. The study's data revealed that MIL-125 could be used to photocatalyzed the cleanup of crude oil spills.

Modified cellulose acetate membranes with bentonite clay (CA/bent) and TiO2 nanoparticles (CA/TiO2) using the phase inversion method are successfully prepared and characterized. These Membranes are favored due to their high salt rejection properties and recyclability. The IR and EDX spectral data indicate the formation of modified membranes. The Scan Electron Microscope micrographs show that the modified membranes have smaller particle sizes with higher porosity than the neat membrane. The average pore diameter is 0.31 µm for neat cellulose acetate membrane (CA) and decreases to 0.1 µm for CA/0.05bent. All modified membranes exhibit tensile strengths and elongation percentages more than the neat membrane. The higher tensile strength and the maximum elongation% are 15.3 N/cm2 and 11.78%, respectively, for CA/0.05bent. The thermogravimetric analysis of modified membranes shows higher thermal stability than the neat membrane. The modified membranes exhibit enhanced wettability and hydrophilicity compared with cellulose acetate, by measuring the contact angle which decreases from 60° (CA) to 40° (CA/0.1bent). The ultrafiltration tests indicated that the CA/bent and CA/TiO2 are better than CA. The most efficient nanocomposite membrane is CA/0.05bent with 100% removal of (BSA) from industrial water with a flux equal to 9.5 mL/min under an applied pressure of 20 bar. Thus, this study introduces a novel ultrafiltration membrane (CA/0.05bent) that can be used effectively to completely remove bovine serum albumin from contaminated water.