Malaysian Journal of Analytical Sciences Vol 23 No 1 (2019): 90 - 99

FACILE TECHNIQUE FOR THE IMMOBILISATION OF TIO₂ NANOPARTICLES ON GLASS SUBSTRATES FOR APPLICATIONS IN THE PHOTOCATALYTIC SELF-CLEANING OF INDOOR AIR POLLUTANTS

(Salutan nanopartikel TiO₂ ke atas Substrat Kaca Melalui Teknik Mudah untuk Penyingkiran Bahan Pencemar Udara dalaman Melalui Proses Fotokatalisis)

Kah Hon Leong¹*, Jia Quan Lee², A. Ashok Kumar³, Lan Ching Sim¹, Saravanan Pichiah⁴

¹Department of Environmental Engineering, Faculty of Engineering and Green Technology,

Universiti Tunku Abdul Rahman, Jalan Universiti, Bandar Barat, 31900 Kampar, Perak, Malaysia

²Environmental Engineering Laboratory, Department of Civil Engineering, Faculty of Engineering,

University of Malaya, 50603 Kuala Lumpur, Malaysia

³Department of Chemical Engineering, School of Engineering and Technology,

Periyar Maniammai University, Thanjavur - 613 403, India

⁴Department of Environmental Science and Engineering,

Indian Institute of Technology (ISM) Dhanbad- 826004, Jharkhand, India

*Corresponding author: khleong@utar.edu.my

Received: 13 April 2017; Accepted: 17 April 2018

Abstract

Self-cleaning technology employing titania (TiO₂) photocatalysts has major applications in the removal of indoor air pollutants. Pollutant removal efficiency significantly depends on the properties of the photocatalyst thin film, which is deposited on substrates. The present work developed a facile immobilisation technique that is based on simple sol–gel process. In this technique, TiO₂ nanoparticles are spray-coated onto a porous glass substrate. The uniformity of the TiO₂ coating on the glass surface was studied using a dynamic flowsense charge-coupled device camera. The influence of different TiO₂ nanoparticle concentrations in the ethanol phase was identified through rheological analysis, which showed that nanoparticle concentration is a crucial factor that affects the uniformity of the coating layer. The ability of the obtained material to catalyse formaldehyde photodegradation in presence of artificial UV light was investigated. Results demonstrated that >15.0 g/L TiO₂ is required to activate formaldehyde photodegradation and that uniform surface coatings with sufficient surface thickness can be obtained by spraying TiO₂nanoparticles on glass substrates at concentrations of more than 15.0 g/L. This study demonstrated that uniformly coated photocatalysts for the efficient self-cleaning of indoor air pollutants can be fabricated through a facile technique.

Keywords: self-cleaning, TiO₂, sol-gel, formaldehyde, photocatalysis

Abstrak

Teknologi pembersihan menggunakan TiO₂ sebagai fotokatalis yang memainkan peranan penting terutamanya dalam menyingkirkan bahan pencemar udara dalaman. Pembersihan bahan pencemar ini sangat bergantung kepada ketebalan filem salutan terbentuk pada substrat. Dalam kajian ini teknik mudah dapat dicapai melalui proses sol-gel dan diikuti dengan salutan semburan TiO₂berliang nanopartikel ke atas substrat kaca. Keseragaman pembentukan titania bersalut pada permukaan kaca dikaji menggunakan kamera “gabungan cas dinamik flowsense. Pengaruh kepekatan nanopartikle TiO₂ yang berbeza-beza dalam fasa etanol membawa kepada analisis reologi. Kajian reologi menunjukkan keberkesanan kepekatan nanopartikel bagi mendapatkan lapisan salutan yang seragam. Keberkesanan salutan dinilai dengan penyingkiran formaldehid dalam kehadiran cahaya UV tiruan. Keputusan penyingkiran menunjukkan bahawa kepekatan TiO₂ yang tinggi dengan melebihi 15.0 g/L menunjukkan penyingkiran formaldehid pada tahap yang ketara disebabkan oleh keseragaman salutan pada permukaan kaca serta ketebalan permukaan yang mencukupi. Kajian ini menunjukkan prestasi yang baik dalam mengesahkan salutan fotokatalis yang seragam untuk meningkat keberkesanan penyingkiran bahan pencemar udara dalaman.

Kata kunci: penyingkiran, TiO₂, sol-gel, formaldehid, fotokatalisis

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