Hydroxyl-/Carboxyl-Rich Graphitic Carbon Nitride/Graphene Oxide Composites for Efficient Photodegradation of Reactive Red 195 and Antibacterial Applications

Efficient photocatalysis activation for reactive red 195 degradation by magnetic MIL-53(Fe)/Fe3O4@TiO2 hybrid nanocomposite

The study investigated the performance of a novel magnetic hybrid MIL-53(Fe)/Fe3O4@TiO2 composite for removing reactive red 195 (RR195) dye from water using UVc light. Various analytical techniques were used to characterize the nanocomposite materials. X-ray diffraction analysis confirmed the presence of MIL-53(Fe) and TiO2 in the composite. FT-IR analysis identified carboxyl and Ti-O-Ti groups in the photocatalyst structure. The study evaluated the effects of pH, dye concentration, photocatalyst dosage, and temperature on RR195 photodegradation. The Langmuir-Hinshelwood kinetic model provided the best fit for the reaction rate. Optimal conditions for an 84 % dye degradation were found at a photocatalyst dose of 15 mg/100 mL, pH 3, dye concentration of 100 mg/L, and 35 °C after 120 minutes of UVc light exposure. Thermodynamic analysis indicated an endothermic reaction with positive values for Δ#H and negative values for Δ#S. The MIL-53(Fe)/Fe3O4@TiO2 composite demonstrated excellent stability and achieved over 90 % dye degradation after five cycles. Overall, the composite shows promise for treating wastewater with dyes.

Photocatalytic Degradation of Tetracycline Hydrochloride Based on the Structure-Property Exploration of BiOCl

The correlation between structure and properties in the photodegradation reaction of bismuth oxychloride (BiOCl) was explored in this work. Three BiOCl samples with different sizes, morphological structures, and defects were prepared through a hydrothermal method with experimental manipulation. Their structural properties were comprehensively characterized using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, electron spin resonance, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy, and photoluminescence. Taking the photodegradation of tetracycline hydrochloride (TC-HCl) as the probe reaction, we found that high activity could be achieved by decreasing their crystal size and thickness, introducing proper defects in the structure, and assembling the nanosheets to get microball structure. Combined with radical-scavenge experiments and electron spin resonance (ESR) spin-trap spectra, we conclude that ̇O2- was the dominant reactive oxygen species for the degradation reaction. The degradation detailed pathway of TC-HCl was further analyzed using liquid chromatography-mass spectrometry. This work explores the structure-property correlation of BiOCl and provides strategies for the rational design of active photocatalysts for water remediation.