Sains Malaysiana 43(2)(2014): 261–265

Using a Pilot Plant to Synthesise ZnO Powder: Particle Characterisation and

Marine Toxicity Studies

(Menggunakan Loji Pandu untuk Mensintesis Serbuk ZnO: Pencirian Partikel dan Kajian

Ketoksikan Marin)

S. MAHMUD*¹& Z. DIN²

¹Zinc Oxide Research & Innovation (ZORI) Team, Nano-Optoelectronic Research Lab

School of Physics, Universiti Sains Malaysia, 11800 Pulau Pinang, Malaysia

²Academy of Sciences Malaysia, 902-4 Jalan Tun Ismail, 50480 Kuala Lumpur

Malaysia

Received: 7 January 2013/Accepted: 19 July 2013

ABSTRACT

A zinc oxide (ZnO) pilot plant furnace was used to synthesize ZnO nanoparticles at very high capacities in a range of 1-4 t/month. The 4-t custom-designed furnace was used to synthesize ZnO particles possessing primary nanoparticles resembling rods and grains. At a combustion temperature of 1000-1300°C, zinc vapour was oxidized into ZnO powder in order to produce granular ZnO (ZG) particles. By blowing air into the combustion chamber, ZnO nanorods (ZR) were produced. The ZR specimen exhibited higher XRD intensities, stronger photocatalysis and higher electrical resistance compared to that of ZG sample. However, the ZR sample showed a stronger toxicity to marine phytoplankton, Isochrysis galbana, by starting to inhibit cell growth at 8 mg/L ZnO concentration in seawater whereas ZG sample started showing growth inhibition at a higher ZnO concentration of 32 mg/L. The toxicity of ZnO primary nanoparticles was probably attributed to the dissolution, release and uptake of free zinc ions especially for the case of the higher surface area of ZR particles that exhibited relatively higher zinc concentration on the particle surface, based on the elemental mapping of the electron spectroscopy imaging results.

Keywords: Isochrysis galbana; pilot plant; toxicity; ZnO

ABSTRAK

Satu tanur loji pandu zink oksida (ZnO) digunakan untuk menghasilkan partikel nano ZnO pada kapasiti tinggi dalam julat 1-4 t/bulan. Dengan reka bentuk-khusus, tanur seberat 4 t ini digunakan untuk mensintesis partikel ZnO yang memiliki partikel nano primer menyerupai rod dan butiran. Pada suhu pembakaran 1000-1300°C, wap zink dioksidakan menjadi ZnO untuk menghasilkan partikel butiran ZnO (ZG). Dengan meniup udara ke dalam kebuk pembakaran, nanorod ZnO (ZR) dihasilkan. Sampel ZR mempamerkan keamatan XRD yang lebih tinggi, fotokatalisis yang lebih kuat dan kerintangan elektrik yang lebih tinggi jika dibandingkan dengan ciri sampel ZG. Walau bagaimanapun, sampel ZR menunjukkan ketoksikan yang lebih kuat terhadap fitoplankton marin, Isochrysis galbana dengan merencat pertumbuhan sel pada kepekatan 8 mg/L ZnO dalam air laut manakala sampel ZG menunjukkan rencatan pertumbuhan sel pada kepekatan 32 mg/L. Ketoksikan partikel nano primer ZnO mungkin disebabkan oleh pelarutan, pembebasan dan pengambilan ion bebas zink terutama untuk kes partikel ZR yang memiliki keluasan permukaan yang lebih tinggi dan kepekatan zink relatif yang lebih tinggi di permukaan partikel, berdasarkan kepada data pemetaan unsur daripada maklumat pengimejan elektron spektroskopi.

Kata kunci: Isochrysis galbana; ketoksikan; loji pandu; ZnO

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*Corresponding author; email: shahromx@usm.my