Textural Enhancement of Hydrothermally Grown TiO2 Nanoparticles and Bilayer-Nanorods

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Mechanics, Materials Science & Engineering, July 2017 – ISSN 2412-5954

Textural Enhancement of Hydrothermally Grown TiO2 Nanoparticles and Bilayer-Nanorods for Better Optical Transport 1

J. Sahaya Selva Mary1, V. Chandrakala1, Neena Bachan1, P. Naveen Kumar1, K. Pugazhendhi1, J. Merline Shyla1,a 1 – Department of Physics, Energy NanoTechnology Centre (ENTeC), Loyola Institute of Frontier Energy (LIFE), Loyola College, Chennai, India a – jmshyla@gmail.com DOI 10.2412/mmse.9.99.459 provided by Seo4U.link

Keywords: bilayer-nanorods, nanoparticles, hydrothermal, photoconductivity.

ABSTRACT. TiO2 nanostructures have been studied as photoanode materials via improvement of their textural and electronic properties for Dye Sensitized Solar Cells (DSSCs). They have exhibited appreciable photovoltaic performance owing to their excellent electron transport and high specific surface area. We report herein, the comparative analysis of TiO2 nanoparticles (TPs) and Bilayer-TiO2 nanorods (B-TRs) prepared by hydrothermal method at 200 ºC for 12 h and 120 ºC for 12 h respectively using an autoclave unit. The as-synthesized samples were characterized using High Resolution Scanning Electron Microscopy (HR-SEM), Energy Dispersive X-ray (EDAX), Fourier Transform Infrared (FT-IR) spectroscopy, Ultra Violet -Visible Spectroscopy (UV-Vis) and Photoconductivity techniques. The morphological results showed that the TPs are spherical in shape with diameter in the range of 18-29 nm and the B-TRs revealed the formation of hierarchical nanostructures on top of aligned nanorod trunks possessing porous nature and dimensions of ~ 262 nm diameter and ~ 660 nm length. FTIR spectra confirmed the presence of Ti-O-Ti vibrations in both the cases. The optical properties of TPs and B-TRs showed a strong absorption edge in the UV region. Photoconductivity techniques revealed the ohmic nature of the samples with a linear increase in both dark and photocurrent with corresponding increase in the applied field. However, in B-TRs there is a significant increase in photocurrent than TPs which suggests a strong capability of absorbing light. Thus we can conclude that the bilayer nanostructure with better photoresponse, can be used as a promising photo anode material for DSSCs.

Introduction. In the past decade, extensive research has been done in the development of technology for efficient utilizing of renewable energy. Among them, photovoltaic is considered as the most promising technology due to its availability, sustainability and reliability [1-2]. Although photovoltaic devices built on silicon or compound semiconductors have achieved high efficiency for practical use, they still require major breakthrough to meet the long-term goal of very-low cost production [3]. Among the various semiconducting metal oxides, TiO2 has attracted considerable attention in the field of energy conversion and environmental protection [4] due to its cost effectiveness, non-toxic nature, accessibility, stability [5] and unique photoelectric conversion capability [6]. Functional properties of TiO2 are influenced by many factors such as crystallinity, particle size, surface area, and synthesis techniques [7]. TiO2 nanostructures have been studied as photoanode materials for DSSCs and they have exhibited appreciable photovoltaic performance owing to their excellent electron transport and high specific surface area [8]. Synthesis methods such as hydrothermal, solvothermal, sol-gel, direct oxidation, chemical vapour deposition (CVD), electro deposition, and microwave methods have been used for the synthesis of TiO2 nanostructures [9]. Among these, hydrothermal technique is the most important and promising fabrication method for nanoscale materials [10]. In this study, a comparative analysis of TiO2 nanostructures (TPs and BTRs), prepared by hydrothermal method using Teflon-lined stainless steel autoclave was investigated.

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© 2017 The Authors. Published by Magnolithe GmbH. This is an open access article under the CC BY-NC-ND license http://creativecommons.org/licenses/by-nc-nd/4.0/

MMSE Journal. Open Access www.mmse.xyz


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