Formulation of silver phosphate/graphene/silica nanocomposite for enhancing the photocatalytic degradation of trypan blue dye in aqueous solution.

Photocatalytic degradation of several harmful organic compounds has been presented as a potential approach to detoxify water in recent decades. Trypan Blue (TB) is an acidic azo dye used to distinguish live cells from dead ones and it's classified as a carcinogenic dye. In this study, silver phosphate (Ag3PO4) nanoparticles and novel Ag3PO4/graphene/SiO2 nanocomposite have been successfully prepared via simple precipitation method. Afterward, their physical properties, chemical composition, and morphology have been characterized using SEM, EDS, TEM, SAED, BET, XRD, FTIR and UV-VIS spectroscopy. The specific surface area of Ag3PO4 and Ag3PO4/G/SiO2 nanocomposite were reported to be 1.53 and 84.97 m2/g, respectively. The band gap energy of Ag3PO4 and Ag3PO4/G/SiO2 nanocomposite was measured to be 2.4 and 2.307 eV, respectively. Photocatalytic degradation of Trypan blue (TB) was studied at different parameters such as pH, catalyst dosage, initial concentration, and contact time. The results showed that, at initial dye concentration of 20 ppm, pH = 2, and using 0.03 g of Ag3PO4/G/SiO2 as a photocatalyst, the degradation percent of TB dye in the aqueous solution was 98.7% within 10 min of light exposure. Several adsorption isotherms such as Langmuir, Freundlich, and Temkin adsorption isotherms have been tested in addition to the photocatalytic degradation kinetics. Both catalysts were found to follow the Langmuir isotherm model and pseudo-second-order kinetic model. Finally, the possible photocatalytic performance mechanism of Ag3PO4/G/SiO2 was proposed.

Efficient removal of bovine serum albumin from water by cellulose acetate membranes modified with clay and titania nano particles.

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.

Efficient photocatalytic degradation of petroleum oil spills in seawater using a metal-organic framework (MOF).

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.