This work reports a comprehensive study on the mechanisms for material formation, charge separation, persulfate activation, and photocatalytic degradation of fluoroquinolone antibiotics (e.g., ofloxacin (OFX), levofloxacin (LFX), and ciprofloxacin (CFX)) under LED visible light using the ZIF-8@Bi₂MoO₆ (BIZ) heterojunction. The BIZ heterojunction was synthesized by the combination of solvothermal and sol–gel methods and characterized by SEM, TEM, XRD, EDX, FTIR, PL, EIS, BET, TGA, and UV-vis DRS analyses. The results show that using 500 mg L⁻¹ BIZ (10% ZIF-8) with 500 mg L⁻¹ Na₂S₂O₈, at unadjusted pH for 25 min of irradiation results in an excellent photocatalytic activity with a degradation efficiency of 56.52% CFX, 85.70% LFX, and 96.36% OFX. The OFX degradation rate constant by BIZ was 3.2 and 23.3 times higher than those by Bi₂MoO₆ and ZIF-8, respectively. These high efficiencies are attributed to the high charge separation rates for the photo-generated carriers in the heterojunction structure. The activity of radicals in the photocatalytic process as well as their role in the OFX removal was in the order of SO₄˙⁻ > O₂˙⁻ > h⁺ > ¹O₂ > HO˙. The mechanisms of charge separation, persulfate activation, and degradation pathway were then proposed for the photocatalytic removal of OFX using the BIZ heterojunction under visible light.

Preparation of nano emulsions from Elsholtzia kachinensis and Elsholtzia ciliata essential oils for antibacterial and anticancer activities.

In this work, a green, novel, fast, and facile approach for synthesizing a SiO₂/C nanocomposite series from rice husk (RH) through quenching and grinding techniques has been reported along with its application for the adsorptive removal of Reactive Red 120 (RR120) dye from an aqueous solution. The effect of carbonization temperature on the textural and interfacial features of RH was confirmed by scanning electron microscopy (SEM), while the structure and elemental composition of the as-synthesized RH were investigated via XRD, Brunauer-Emmett-Teller (BET), FT-IR, Raman, and X-ray photoelectron spectroscopy (XPS). The RH had a high surface area (521.35 m² g^-1), large micropores, mesopores, and total pore volumes of 0.5059, 3.9931, and 5.2196 cm³ g^-1, while SiO₂ and C were the two major components. In the batch adsorption test, the effects of pH, contact time, adsorbent mass, temperature, and initial RR120 concentration were investigated. The maximum adsorption capacity was fitted by Langmuir, Freundlich, Temkin, Dubinin-Radushkevich (D-R), Hasley, Harkins-Jura, and BET isotherm models, and Langmuir was the best-fitted model. In addition, the pseudo-first-order, pseudo-second-order, intraparticle diffusion, and Elovich chemisorption models were used to explain the adsorption kinetics. Additionally, the values of Gibbs free energy, enthalpy, and entropy thermodynamics suggested that the RR120 adsorption phenomenon by RH8-3 was endothermic and spontaneous. The adsorption process was controlled by a physical mechanism, and the maximum adsorption capacity was found to be 151.52 mg g^-1 at pH 2, with a contact time of 90 min, adsorbent amount of 0.03 g, and temperature of 313 K. The adopted technique may open up a new alternative route for the mass utilization of RH for the removal of dyes in water and wastewater and also for various practical applications.