Effects of iron ions, doping methods and nanotubular morphology on TiO2 solar photocatalytic performance

Abstract

The effects of Fe2+ and Fe3+ as TiO2 cocatalysts were studied, and the experimental results showed that Fe3+ was more efficient than Fe2+, which needed an intermediate reaction to produce hydroxyl radicals. TiO2 was modified with the aim of improving its structural, optical, and adsorption properties, thus improving its photocatalytic performance. The light range of the catalyst activation process was expanded, which increased the catalyst's ability to absorb visible light. Consequently, this study exploits solar energy in photocatalysis by Fe ion doping using different methods, including impregnation, photodeposition, solvothermal doping, and hydrothermal doping, and evaluates the influence of each doping method on TiO2 optical properties and photocatalytic activity. Enhancing the catalyst adsorption capacity by morphologically modifying TiO2 nanoparticles into nanotubes using the hydrothermal method increases the catalyst surface area from 55 to 294 m2/g, as shown in the MEB and BET results. The effect of combining morphological changes and Fe3+ doping on TiO2 activity was evaluated. We observed a reduction in the TiO2 band gap from 3.29 to 3.01 eV, absorption edge widening, and an increase in the specific surface area up to 279 m2/g; thus, the synthesized catalyst eliminated Cefixime in 120 min.

Photocatalytic Antimicrobials: Principles, Design Strategies, and Applications

“…228 First of all, the small specific surface area makes the surface of the photocatalyst unable to be in full contact with the light, thus reducing the absorption of light. 229 Second, the photocatalyst with small specific surface area cannot offer enough active sites for photocatalysis reaction, which reduces the efficiency of light conversion and utilization. Finally, such a photocatalyst cannot combine well with bacteria, thus decreasing the photocatalytic inactivation effect.…”

“…Currently, bulk photocatalysts face the birth defect of their small specific surface areas . First of all, the small specific surface area makes the surface of the photocatalyst unable to be in full contact with the light, thus reducing the absorption of light . Second, the photocatalyst with small specific surface area cannot offer enough active sites for photocatalysis reaction, which reduces the efficiency of light conversion and utilization.…”

Recent advances in spinel ferrite-based magnetic photocatalysts for efficient degradation of organic pollutants

“…UV merely accounts for 5% while visible light takes up 46% of entire solar energy, leaving the rest part corresponding to IR. Many reported photocatalysts have band gaps wider than 3.1 eV, which enables them to absorb a tiny portion of solar light (Melki et al 2021). Thus, as for photocatalysts, it is essential to utilize visible light (visible solar energy).…”

TiO2-Decorated by Nano-γ-Fe2O3 as a Catalyst for Efficient Photocatalytic Degradation of Orange G Dye under Eco-friendly White LED Irradiation

“…Using modified TiO 2 , Fe 3+ , and H 2 O 2 , we can significantly enhance the production of ·OH and the degradation of synthetic dyes and other organic pollutants . On the other hand, to perform the conventional photo-Fenton reaction, a Fenton-like reaction by mixing TiO 2 and Fe 3+ /Fe 2+ as catalysts has been developed . Several studies have reported that these TiO 2 /Fe 2 O 3 nanocomposites as catalysts are effective in removing nonbiodegradable contaminants, such as dyes and antibiotics from wastewater .…”

“…Several studies have reported that these TiO 2 /Fe 2 O 3 nanocomposites as catalysts are effective in removing nonbiodegradable contaminants, such as dyes and antibiotics from wastewater . This is caused by an increase in the catalyst surface area, which leads to catalyst activity depletion . Most recently, TiO 2 /γ-Fe 2 O 3 nanocomposites have been developed that have the highest catalytic efficiency and stability for the degradation and removal of organic pollutants such as ciprofloxacin (CIP), metronidazole (MNZ), ibuprofen, Auramine (AM) dye, bisphenol A (BPA), and rhodamine B (RhB) dye …”