Investigating the photocatalytic degradation property of Pt, Pd and Ni nanoparticles-loaded TiO₂ nanotubes powder prepared via rapid breakdown anodization

ABSTRACT

The present study was performed to investigate the photocatalytic efficiency of the titania (TiO₂) nanotubes (NTs) powder prepared via rapid breakdown anodization sensitized individually with Ni, Pd and Pt metal nanoparticles (NPs). The TiO₂ NTs powder had the length of 5–6 μm, with the outer diameter between 20 and 25 nm and the wall thickness of 3–4 nm as observed in the scanning and transmission electron microscopes. The crystal structure analysis employing X-ray diffraction indicated the presence of Pt, Pd and Ni NPs in face-centered cubic phase over the anatase TiO₂ NTs powder. The photocatalytic degradation of methylene blue (MB) was carried out with these photocatalysts. As a result, the performance of the 2 at.% Pt-loaded Pt–TiO₂ NTs nanocomposite was determined to be superior on comparison to other photocatalysts under the current investigation. Fourier-transform infrared spectra confirmed the absence of any adsorption of MB or degraded products onto the surface of all the photocatalysts. The electron paramagnetic resonance analysis substantiated the e⁻ transfer interaction from the conduction band of TiO₂ NTs to Fermi level of Pt NPs has resulted in the better photodegradation process. The possible degradation mechanism using Pt–TiO₂ NTs nanocomposites is discussed.

KEYWORDS:

• Titania
• nanotubes
• powder
• rapid breakdown anodization
• photodegradation

Acknowledgement

TMD thanks Council of Scientific and Industrial Research (CSIR) for the award of Senior Research fellowship (SRF) with sanction order vide no: 08/264/(0007)/2017-EMR-I. TMD, CR and PS gratefully acknowledge UGC-DAE CSR (grant No: CSRKN/CRS-52/2013–14/651) and Dr. G. Amarendra, Director, UGC-DAE CSR, Kalpakkam Node. Dr. S. Amirthapandian, IGCAR, Kalpakkam is acknowledged for the TEM facility. TMD acknowledges Ms. M. Rebeca Sofiya Joice for the efficient support. The authors are thankful to Mr. P. Dhandapani, CSIR-SRF and Ms. V. Manju of CECRI, Karaikudi for the EPR and DRS spectral data, respectively.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by Council of Scientific and Industrial Research (CSIR) [grant number 08/264/(0007)/2017-EMR-I,Senior Research Fellowship (SRF)]; UGC-DAE CSR [grant number CSRKN/CRS-52/2013-14/651].