Doped TiO2 Photocatalysts for the Photocatalytic Degradation Efficiency of Methylene Blue and Humic Acid under Solar Light

In the current research, we successfully prepared TiO2/Ni–Cu–Zn ferrite composite powder for magnetic photocatalyst. The core Ni–Cu–Zn ferrite powder was synthesized using the steel pickling liquor and the waste solution of electroplating as the starting materials. The shell TiO2 nanocrystal was prepared by sol-gel hydrolysis precipitation of titanium isopropoxide [Ti(OC3H7)4] on the Ni–Cu–Zn ferrite powder followed by heat treatment. From transmission electron microscopy (TEM) image, the thickness of the titania shell was found to be approximately 5 nm. The core of Ni–Cu–Zn ferrite is spherical or elliptical shape, and the particle size of the core is in the range of 70–110 nm. The magnetic Ni–Cu–Zn ferrite nanopowder is uniformly encapsulated in a titania layer forming core-shell structure of TiO2/Ni–Cu–Zn ferrite powder. The degradation efficiency for methylene blue (MB) increases with magnetic photocatalyst (TiO2/Ni–Cu–Zn ferrite powder) content. When the magnetic photocatalyst content is 0.40 g in 150 mL of MB, the photocatalytic activity reached the largest value. With a further increase in the content of magnetic photocatalyst, the degradation efficiency slightly decreased. This occurs because the ultraviolet (UV) illumination is covered by catalysts, which were suspended in the methylene blue solution and resulted in the inhibition in the photocatalytic reaction. The photocatalytic degradation result for the relationship between MB concentration and illumination revealed a pseudo first-order kinetic model of the degradation with the limiting rate constant of 1.717 mg/L·min and equilibrium adsorption constant 0.0627 L/mg. Furthermore, the Langmuir–Hinshelwood model can be used to describe the degradation reaction, which suggests that the rate-determining step is surface reaction rather than adsorption is in photocatalytic degradation.

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Efficiency of Photocatalytic Degradation of Humic Acid Using Magnetic Nanoparticles (Fe-doped TiO2@Fe3O4) in Aqueous Solutions

Health Scope ◽

10.5812/jhealthscope.102577 ◽

2020 ◽

Vol 9 (2) ◽

Author(s):

Hossein Moein ◽

Gholamreza Nabi Bidhendi ◽

Naser Mehrdadi ◽

Hossein Kamani

Keyword(s):

Magnetic Nanoparticles ◽

Humic Acid ◽

Aqueous Solutions ◽

Photocatalytic Degradation ◽

High Efficiency ◽

Sol Gel ◽

Reaction Times ◽

Doped Tio2 ◽

Natural Organic Matters ◽

Uv Lamp

Background: Among water pollutants, Natural Organic Matters (NOMs) are highly important for making problems in water treatment plants. Objectives: The main objective of this study was to investigate the efficiency of photocatalytic degradation of humic acid using magnetic nanoparticles (Fe-doped TiO2@Fe3O4) in aqueous solutions. Methods: In the present experiment, Fe-doped TiO2@Fe3O4 nanoparticles were synthesized by the sol-gel method, and SEM, XRD, and DRS analyzes were utilized to characterize the synthesized nanoparticles. The effects of various variables, including pH (3 - 11), initial concentration of humic acid (20 - 80 mg/L), and concentration of nanoparticles (250 - 2000 mg/L) at different reaction times (15 - 60 min) were investigated on the photocatalytic degradation of humic acid. Results: The maximum degradation efficiency of humic acid at pH 3, the initial humic acid concentration of 5 mg/L, nanoparticle dose of 400 mg/L, and reaction time of 60 min using a 15-W bare UV lamp. Conclusions: Due to the high efficiency of photocatalytic degradation, it is proposed to use for the removal of humic acid from water resources.

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