Sains Malaysiana 47(2)(2018): 253-259

http://dx.doi.org/10.17576/jsm-2018-4702-06

Cr₂O₃ Nanoparticles Anchored on ZnO Nanorods as Active Heterostructure Catalysts for Phenol Degradation  

(Zarah Nano Cr₂O₃ Bergabung pada Rod Nano ZnO sebagai Pemangkin Heterostruktur Aktif untuk Degradasi Fenol)

Sze-Mun Lam^1*, Jin-Chung Sin² & Abdul Rahman Mohamed³

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

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

Perak Darul Ridzuan, Malaysia

²Department of Petrochemical Engineering, Faculty of Engineering and Green Technology

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

Perak Darul Ridzuan, Malaysia

³School of Chemical Engineering, Universiti Sains Malaysia, Engineering Campus

Seri Ampangan, 14300 Nibong Tebal, Pulau Pinang,Malaysia

Received: 25 March 2017/Accepted: 1 August 2017

ABSTRACT

With the rapid civilization and industrialization, water pollution is becoming more and more intricate. Heterogeneous photocatalysis using metal oxide loaded ZnO nanorods is a well-known environmental technology to degrade toxic organic pollutants. In this study, Cr₂O₃ particles anchored on the ZnO nanorods (Cr₂O₃/ZnO) were successfully synthesized by a hydrothermal-deposition technique. Microscopic and crystallographic analyses indicated that the synthesized samples consisted of two-phase heterostructure of Cr₂O₃ and ZnO. The photocatalytic results showed that the phenol degradation by Cr₂O₃ /ZnO heterostructures was higher than those of pure ZnO and commercial TiO₂. The synergetic effect between Cr₂O₃ and ZnO was the pivotal reason for the improvement of photoactivity as proven by the photoluminescence and terephthalic acid–photoluminescence analyses.

Keywords: Cr₂O₃; nanocomposite; phenol; photocatalysis; ZnO nanorod

ABSTRAK

Dengan pertamadunan dan perindustrian yang pesat, isu alam sekitar seperti pencemaran air menjadi semakin rumit. Fotopemangkinan heterogen menggunakan logam oksida digabungkan rod nano ZnO adalah teknologi alam sekitar yang terkenal untuk degradasi bahan pencemar organik toksik. Dalam kajian ini, heterostruktur Cr₂O₃/ZnO dengan zarah Cr₂O₃ berpasang pada rod nano ZnO telah berjaya disintesis oleh teknik hidroterma-pemendapan. Analisis mikroskopik dan kristalografi menunjukkan bahawa sampel yang disintesis terdiri daripada dua fasa berheterostruktur Cr₂O₃ dan ZnO. Keputusan fotopemangkinan menunjukkan bahawa degradasi fenol oleh heterostruktur Cr₂O₃/ZnO adalah lebih tinggi berbanding dengan ZnO tulen dan TiO₂ komersial. Kesan sinergi di antara Cr₂O₃ dan ZnO adalah sebab utama peningkatan aktiviti pemfotomangkinan seperti yang dibuktikan oleh analisa fotoluminasi dan asid tereftalik-fotoluminasi. 

Kata kunci: Cr₂O₃; fenol; fotopemangkinan; komposit nano; rod nano ZnO

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*Corresponding author; email: lamsm@utar.edu.my