Synthesis of TiO2 nanoscale rods with MHz femtosecond laser irradiation of single crystal surface and characterisation

M Sivakumar,Krishnan Venkatakrishnan,Bo Tan

doi:10.1063/1.3600705

Abstract

Growth of nanoscale rods on single crystal rutile TiO2 surface irradiated by MHz pulse repetition rate femtosecond laser in nitrogen environment without a catalyst or template is reported. The rods are of 100 nm in width to 1 micron length. Microraman analysis of the laser irradiated surface shows only a decrease in the intensity of active modes as compared to untreated surface. The growth of TiO2 nanorods can be explained by a method combining nanoparticles formation due to expulsion of molten material from laser irradiated spot and their subsequent growth by vapor-liquid-solid process.

Highlights

TiO2 nanostructures have recently attracted widespread research attention because of their diversified functional properties
For instance dye-sensitized solar cells based on TiO2 nanoparticles and 1D nanostructures have shown an efficiency of 8.6 %
The irradiated surfaces were analysed by Scanning Electron Microscopy (SEM), microraman and X-ray diffraction (XRD) techniques

Summary

Introduction

TiO2 nanostructures have recently attracted widespread research attention because of their diversified functional properties. For instance dye-sensitized solar cells based on TiO2 nanoparticles and 1D nanostructures have shown an efficiency of 8.6 %.6. Both wet-chemistry (electrodeposition, sol-gel electrophoresis, hydrothermal methods, solvothermal methods, inverse microemulsion) and dry (thermal evaporation and metal-organic chemical vapor deposition) methods have been investigated to synthesize TiO2 1D nanostructures. Femtosecond laser pulses at MHz pulse repetition rate has shown potential in generating weblike self assembled nanofibrous structures, nanofibers and nanoscale tips of semiconductor, metallic and dielectric materials under atmospheric conditions.[12,13] It has been shown possible to control the size, shape and chemistry of the nanostructures by choosing optimum laser parameters and processing conditions.

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Results

Conclusion