Sains Malaysiana 45(8)(2016): 1265–1273

Pertumbuhan dan Penambahbaikan Nanokomposit Ag-ZnO untuk Aktiviti Fotomangkin

(Growth and Improvement of Ag-ZnO Nanocomposites for Photocatalytic Activity)

M.T.M. AYOB¹, H.M.K. MOHD1, I. ABDUL RAHMAN^1,2, F. MOHAMED^1,2, N.M. HIDZIR^1,2

& S. RADIMAN^1,2*

¹Pusat Pengajian Fizik Gunaan, Fakulti Sains dan Teknologi, Universiti Kebangsaan Malaysia

43600 Bangi, Selangor Darul Ehsan, Malaysia

²Pusat Penyelidikan Teknologi Nuklear, Fakulti Sains dan Teknologi, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor Darul Ehsan, Malaysia

Diserahkan: 20 April 2015/Diterima: 26 November 2015

ABSTRAK

Kami melaporkan hasil kajian terhadap nanokomposit Ag-ZnO dengan nisbah berat yang berbeza bagi Ag:ZnO (0:10, 7:10 & 25:10) yang telah disediakan melalui kaedah sonokimia. Kajian fotomangkin terhadap nanokomposit Ag-ZnO menunjukkan peningkatan kecekapan fotomangkin terhadap foto-penguraian larutan akues metilena biru berbanding nanobahan ZnO tulen di bawah penyinaran cahaya nampak. Sampel Ag-ZnO pada nisbah 7:10 menunjukkan aktiviti fotomangkin terbaik dan mencapai kadar penguraian sehingga 94% bagi tempoh masa penguraian selama 80 min, diikuti 86% bagi sampel ZnO tulen dengan menggunakan kaedah yang sama. Morfologi, struktur bahan, sifat optik dan kehabluran bagi nanokomposit Ag-ZnO juga dibincangkan menerusi data yang diperoleh melalui mikroskop elektron transmisi, spektroskopi ultralembayung-cahaya nampak dan difraktometer analisis sinar-X. Hasil kajian menunjukkan bahawa dengan penambahan zarah Ag kepada ZnO telah meningkatkan kadar serapan cahaya bagi ZnO di kawasan cahaya nampak dan meningkatkan kadar pemisahan cas foto-aruhan bagi menghasilkan rawatan air tercemar pewarna yang lebih baik.

Kata kunci: Ag-ZnO; foto-penguraian; metilena biru; rawatan air tercemar

ABSTRACT

We report the research results of Ag-ZnO nanocomposites with different weight ratio of Ag:ZnO (0:10, 7:10 & 25:10) which were prepared by sonochemical method. The photocatalytic study of Ag-ZnO nanocomposites showed enhanced photocatalytic efficiency of methylene blue aqueous solution photodegradation compared with the pure ZnO nanoparticle under visible light irradiation. The Ag-ZnO at a ratio of 7:10 displayed the best photocatalytic activity and reached 94% degradation rate for 80 min degradation time, followed by 86% for pure ZnO by the same method. The morphological, structural, optical properties and crystallinity of the Ag-ZnO nanocomposites were also elucidated with the data obtained from transmission electron microscopy, ultraviolet-visible spectroscopy and X-ray diffractometer analyses, respectively. The results showed that by adding particles of Ag to ZnO increases the absorbance of ZnO in the visible region and enhances the photoinduced charge separation rate for better wastewater treatment.

Keywords: Ag-ZnO; methylene blue; photodegradation; wastewater treatment

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*Pengarang untuk surat-menyurat; email: shahidan@ukm.edu.my