Swati Sood

Highly effective Fe-doped TiO2 nanoparticles photocatalysts for visible-light driven photocatalytic degradation of toxic organic compounds

This paper reports the synthesis of various molar concentrations of iron (Fe)-doped TiO2 nanoparticles and their efficient use as potential photocatalysts for photocatalytic degradation of toxic and harmful chemical, paranitrophenol. The nanoparticles were synthesized by a novel and facile ultrasonic assisted hydrothermal method and characterized in detail by various analytical techniques in terms of their morphological, structural, compositional, thermal, optical, pore size distribution, etc properties. The photocatalytic activities of the as-prepared Fe-doped TiO2 nanoparticles were examined under visible light illumination using para-nitrophenol as target pollutant. By detailed experimental findings revealed that the Fe dopant content crucially determines the catalytic activity of TiO2 nanoparticles. The maximum degradation rate of para-nitrophenol observed was 92% in 5 h when the Fe(3+) molar concentration was 0.05 mol%, without addition of any oxidizing reagents. The prepared nanoparticles demonstrated excellent photocatalytic response because of their small size, excellent crystalline structure, increase in threshold wavelength response and maximum separation of photogenerated charge carriers. Further, the determination of reaction intermediates has also been carried out and plausible mechanism of photocatalytic degradation of para-nitrophenol has been proposed.

The visible light-driven photocatalytic degradation of Alizarin red S using Bi-doped TiO2 nanoparticles

In this paper we report the preparation of a series of Bi3+-doped TiO2 nanoparticles with different Bi-concentrations, i.e. 0.25–5% by a facile sol–gel process and their application as an efficient photocatalyst. The detailed characterization revealed that the Bi-doped TiO2 catalysts possess densely grown nanoparticles, a high specific surface area, crystalline anatase TiO2 and good optical properties. The incorporation of Bi3+ into the TiO2 lattice led to the expansion of the TiO2 spectral response into the visible light region and the efficient separation of charge carriers. The prepared samples were employed for the photocatalytic degradation of Alizarin red S dye (ARS) under visible light illumination. It was found that the incorporation of the Bi3+ ions in the TiO2 lattice causes a marked improvement in the photocatalytic degradation of the ARS dye; however, the degradation efficiency depended upon the Bi+3 ion doping concentration and the dose of the prepared catalyst. The detailed photocatalytic experiments confirmed that the 1% Bi+3 ion doping concentration and 0.1 g L−1 dose exhibited the best photocatalytic degradation efficiencies for the model dye. Moreover, more than 80% degradation of ARS was observed by the prepared Bi-doped catalysts within 90 minutes under visible light. The synthesized Bi-doped TiO2 nanoparticles revealed a superior photocatalytic behavior towards the photocatalytic degradation of ARS under similar experimental conditions, as compared to the synthesized TiO2 nanoparticles and other commercially available derivatives (TiO2 PC-50 and TiO2 P25).

Photocatalytic degradation of the antibiotic levofloxacin using highly crystalline TiO2 nanoparticles

This paper reports the photocatalytic degradation of levofloxacin (LEVO), a widely used antibiotic drug, using highly crystalline TiO2 nanoparticles. The TiO2 nanoparticles were synthesized using a sol–gel technique and characterized by various techniques in terms of their morphological, structural, compositional, thermal and optical properties. The detailed studies revealed that the prepared TiO2 nanoparticles are grown in high density, are highly crystalline and exhibit good optical properties. Over 90% photocatalytic degradation of LEVO was achieved by the prepared TiO2 nanoparticles in 120 min under UV light illumination. By comparing the photocatalytic degradation properties of the prepared TiO2 nanoparticles with a commercially available TiO2 catalyst (P25 and PC-50), it was observed that the as-synthesized TiO2 nanoparticles exhibited a superior photocatalytic performance towards LEVO. Moreover, the antibiotic efficacy of levofloxacin was tested against E. coli and interestingly, it was found that its antibacterial activity was drastically inhibited after the treatment of the drug solutions with the prepared photocatalyst.