Catalyst Dose Concentration Research Articles

Enhanced Organic Pollutant Removal Efficiency of Electrospun NiTiO3/TiO2-Decorated Carbon Nanofibers

A nanocomposite comprised of nickel titanate/titania nanoparticles decorated with carbon nanofibers (NiTiO3/TiO2-decorated CNFs) is successfully synthesized via electrospinning and further utilized for methylene blue (MB) photodegradation. The morphology, phase, structural and chemical composition of the nanocomposite is investigated via scanning electron microscope, X-ray diffraction and transmission electron microscope equipped with energy dispersive X-ray. A mathematical model is developed to predict the photocatalytic activity of the produced nanocomposite by considering parameters such as initial dye concentration, light intensity, reaction temperature, and catalyst dosage. The reaction rate constant K1 decreased from 0.0153 to 0.0044 min-1 with an increase in the MB concentration from 5 to 15 mg L-1, while K2, K3, and K4 were found to increase with the increase in reaction temperature (0.0153 to 0.0222 min-1), light intensity (0.0153 to 0.0228 min-1) and catalyst dose concentration (0.0153 to 0.0324 min-1), respectively. The results obtained are found to be in good agreement with the modeling results and showed effective photodegradation activity. The performance of our catalyst is found to be better compared to other catalysts previously reported in the literature. The recyclability data of the synthesized NiTiO3/TiO2-decorated CNFs catalyst for four runs show that the catalyst is quite stable and recyclable. This nanocomposite photocatalyst offers a low-cost solution for wastewater pollution problems and opens new avenues to further explore the electrospinning method for the synthesis of nanocomposites.

Effective degradation of ciprofloxacin and Cr (VI) by surface plasmon resonance induced photocatalyst Ag (0)/BiVO4@SiO2: Performance and mechanism

A novel plasmonic Ag (0)/BiVO4@SiO2 composite was fabricated by encapsulation of SiO2 on the surface of porous BiVO4 followed by the loading of different percentage of Ag nanoparticle on the surface of BiVO4/SiO2 using reducing agent. The optimized Ag (0)/BiVO4@SiO2 manifests the highest photocatalytic performance towards degrading ciprofloxacin (CIP) and hexavalent chromium Cr (VI), which degradation efficiencies are 93.3 % and 95.6 % respectively. Such enhancement in photocatalytic degradation could be due to the absorption in the visible light range induced by LSPR (localized surface Plasmon resonance) and effective transportation and interfacial separation of photogenerated charge carriers in Ag(0)/BiVO4@SiO2. The impacts of different key parameters such as (pH, different catalyst dose concentration, and various substrate concentrations) are investigated systematically. The excellent mineralization capacity and recyclability performance of Ag (0)/BiVO4@SiO2 are mainly attributed due to the presence of reactive radicals such as h+, OH., O2−., e-s produced during the reaction time h+, and OH., are considered as the dominant species for the photocalytic oxidation of CIP and O2−., e− are for the reduction of Cr (VI). Therefore, this present study not only report on plasmonic photocatalyst but also new design of photocatalyst capable of degrading efficiently antibiotics as well as toxic heavy metal.