Bandgap engineering of TiO2 nanoparticles through MeV Cu ions irradiation

Ishaq Ahmad; Muhammad Usman; Ting-kai Zhao; Sara Qayum; Iram Mahmood; Arshad Mahmood; Abdoulaye Diallo; Camillus Obayi; Fabian Ifeanyichukwu Ezema; Malik Maaza

Arabian Journal of Chemistry (Jan 2020)

Bandgap engineering of TiO2 nanoparticles through MeV Cu ions irradiation

Ishaq Ahmad,
Muhammad Usman,
Ting-kai Zhao,
Sara Qayum,
Iram Mahmood,
Arshad Mahmood,
Abdoulaye Diallo,
Camillus Obayi,
Fabian Ifeanyichukwu Ezema,
Malik Maaza

Affiliations

Ishaq Ahmad: Experimental Physics Labs, National Centre for Physics, Quaid-i-Azam University Campus, Islamabad 44000, Pakistan; NPU-NCP Joint International Research Center on Advanced Nanomaterials and Defects Engineering, Northwestern Polytechnical University, Xi'an 710072, China; UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria, South Africa; Nanosciences African Network (NANOAFNET), iThemba LABS, National Research Foundation, P O Box 722, Somerset West 7129, South Africa; Corresponding authors at: UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, P O Box 392, Pretoria, South Africa.
Muhammad Usman: Experimental Physics Labs, National Centre for Physics, Quaid-i-Azam University Campus, Islamabad 44000, Pakistan
Ting-kai Zhao: NPU-NCP Joint International Research Center on Advanced Nanomaterials and Defects Engineering, Northwestern Polytechnical University, Xi'an 710072, China; School of Materials Science & Engineering, Northwestern Polytechnical University, Xi'an 710072, China
Sara Qayum: Experimental Physics Labs, National Centre for Physics, Quaid-i-Azam University Campus, Islamabad 44000, Pakistan; Physics Department, Allama Iqbal Open University, Islamabad, Pakistan
Iram Mahmood: Department of Industrial Engineering, College of Engineering, King Khalid University, Abha 61413, Saudi Arabia
Arshad Mahmood: National Institute of Lasers and Optronics (NILOP), P.O Nilore, Islamabad, Pakistan
Abdoulaye Diallo: Department of Physics and Chemistry, Faculty of Sciences and Technologies of Formation and Education, University Cheikh Anta Diop (UCAD), B.P. 5036 Dakar-Fann, Senegal; UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria, South Africa; Nanosciences African Network (NANOAFNET), iThemba LABS, National Research Foundation, P O Box 722, Somerset West 7129, South Africa
Camillus Obayi: Department of Metallurgical & Materials Engineering, University of Nigeria, Nsukka 410001, Enugu State, Nigeria
Fabian Ifeanyichukwu Ezema: UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria, South Africa; Nanosciences African Network (NANOAFNET), iThemba LABS, National Research Foundation, P O Box 722, Somerset West 7129, South Africa; Department of Physics & Astronomy, University of Nigeria, Nsukka 410001, Enugu State, Nigeria; Corresponding authors at: UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, P O Box 392, Pretoria, South Africa.
Malik Maaza: UNESCO-UNISA Africa Chair in Nanosciences/Nanotechnology, College of Graduate Studies, University of South Africa, Muckleneuk Ridge, PO Box 392, Pretoria, South Africa; Nanosciences African Network (NANOAFNET), iThemba LABS, National Research Foundation, P O Box 722, Somerset West 7129, South Africa

Journal volume & issue: Vol. 13, no. 1
pp. 3344 – 3350

Abstract

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The effect of 5 MeV Cu++ ions irradiation on structural and optical properties of Anatase TiO2 nanoparticles (TiO2-NPs) is investigated. For this purpose, TiO2-NPs are irradiated with different Cu++ ions fluences, ranging from 1 × 1015 to 1 × 1016 ions/cm2 at room temperature. XRD results confirm the Ti3O7 phase appear at the dose of 5 × 1015 ions/cm2 and peak intensity of Ti3O7 phase gradually increases with an increase of Cu++ ions irradiation dose. At the dose of 1 × 1016 ions/cm2 TiO2 Anatase phase were transformed to Rutile phase. Same observations are confirmed from Raman spectroscopy. High resolution transmission electron microscopy (HRTEM) reveals that morphology converted into wavy shape and crystal structure detrioted with increase Cu ion irradiation dose to form vacancy loops and interstitial loops. Scanning electron microscopy (SEM) shows that TiO2-NPs have been fused to form a cluster of nanoparticles at high Cu ion beam dose, while bandgap of TiO2-NPs reduces from 3.19 eV to 2.96 eV as a function of Cu++ irradiation fluence. These phase transformations and crystal damage are the responsible for optical bandgap reduction. The mechanism for the currently observed phase transformation of TiO2 and coalescence of TiO2-NPs are discussed in term of thermal spikes model. Keywords: TiO2 nanoparticles, Cu++ irradiation, Rutile phase, Coalescence of NPs, Bandgap engineering

Published in Arabian Journal of Chemistry

ISSN: 1878-5352 (Print)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Science: Chemistry
Website: http://www.journals.elsevier.com/arabian-journal-of-chemistry/

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