Sains Malaysiana 48(5)(2019): 1129–1135

http://dx.doi.org/10.17576/jsm-2019-4805-22

 

Peningkatan Kecekapan Pemisahan Air Menggunakan g-C3N4 yang Disinar Gama

(Improvement of Water Splitting Efficiency using Gamma Irradiated g-C3N4)

 

NURUL AIDA MOHAMED¹, JAVAD SAFAEI¹, AZNAN FAZLI ISMAIL^2,3, MOHAMAD FIRDAUS MOHAMAD NOH¹, MOHD FAIRUZ SOH¹, MOHD ADIB IBRAHIM¹, NORASIKIN AHMAD LUDIN¹ & MOHD ASRI MAT TERIDI^1*

 

¹Solar Energy Research Institute (SERI), Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia

 

²Nuclear Science Program, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia

 

³Center for Frontier Science, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia

 

Diserahkan: 3 Julai 2018/Diterima: 13 Mac 2019

 

ABSTRAK

Dalam kajian ini, kesan sinar gama ke atas bahan semikonduktor g-C3N4 kGy (0.1 kGy dan 0.5) dibincangkan dan dibandingkan dengan sampel yang tidak disinar untuk melihat perbezaanya. Bahan g-C3N4 disintesis dari urea melalui proses pempolimeran haba pada suhu 520°C. Struktur dan morfologi g-C3N4 dianalisis dengan menggunakan pembelauan Sinar- X (XRD), spektroskopi transformasi Fourier inframerah (FT-IR), mikroskop pengimbas elektron pancaran medan dengan spektroskopi tenaga sinar-X (FESEM-EDX), spektroskopi cahaya nampak - ultraungu (UV-Vis) dan ketumpatan arus (LSV). Sinar gama telah mengubah struktur ikatan g-C3N4 dan mengurangkan sela jalur iaitu daripada 2.80 eV kepada 2.72 eV. Di samping itu, sampel g-C3N4 yang disinar pada 0.1 kGy menghasilkan prestasi lima kali ganda lebih tinggi iaitu daripada 3.59 μAcm-2 kepada 14.2 μAcm-2 pada 1.23 V lawan Ag/AgCl dalam larutan elektrolit 0.5 M Na2SO4 (pH7). Kesimpulannya, keputusan kajian menunjukkan bahan semikonduktor yang dirawat dengan sinar gama berpotensi untuk meningkatkan fotoelektrokimia (PEC) pemisahan air.

 

Kata kunci: g-C3N4, pemisahan air; sela jalur tenaga; sinar gama

 

ABSTRACT

In this study, the effect of gamma radiation on g-C3N4 semiconductor material (0.1 and 0.5 kGy) was discussed and compared to the non-irradiated sample in order to investigate the difference. The g-C3N4 material was synthesised from urea by thermal polymerization at the temperature of 520°C. The structure and morphology of the g-C3N4 were analysed by X-ray diffractometer (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscope with energy dispersive X-ray spectroscopy (FESEM-EDX), ultraviolet- visible (UV-Vis), profilometer and photocurrent density (LSV). The finding indicates that gamma radiation has changed the bonding structure of the g-C3N4 and reduces the optical band gap energy from 2.80 to 2.72 eV. In addition, the irradiated g-C3N4 sample at 0.1 kGy has five times better performance which increases from 3.59 μAcm-2 to 14.2 μAcm-2 at 1.23 V versus Ag/AgCl in 0.5 M Na2SO4 electrolyte solution (pH7). As a conclusion, this study shows that the treated semiconductor material with gamma-ray potentially to increase the photoelectrochemical efficiency.

 

Keywords: g-C3N4; energy band gap; gamma radiation; water splitting

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