Sains Malaysiana 41(4)(2012): 439-444
Penentuan Aras Jalur Tenaga Kompleks Tungsten Nitrosilditiolena
(Determination of
Band Energy Levels for Tungsten Nitrosyldithiolene)
Mark
Lee Wun Fui1, Ng Kim Hang1,
Lorna Jeffery Minggu2, Akrajas Ali Umar3 & Mohammad B. Kassim 1, 2 *
1Pusat Pengajian Sains Kimia dan Teknologi Makanan, Fakulti Sains dan Teknologi
Universiti Kebangsaan Malaysia, 43600 UKM, Bangi, Selangor D.E., Malaysia
2Institut Sel Fuel, Universiti Kebangsaan Malaysia
43600
UKM, Bangi, Selangor D.E., Malaysia
3Institut Kejuruteraan Mikro dan Nanoelektronik (IMEN), Universiti Kebangsaan Malaysia
43600
UKM Bangi, Selangor D.E., Malaysia
Diserahkan: 29 Jun 2011 / Diterima: 20 Oktober 2011
ABSTRAK
Sifat-sifat kimia dan fizik kompleks tungsten nitrosilditiolena dengan formula am [WTp*(NO)(L)] dengan Tp* = tris(3,5- dimetilpirazolil)hidroborat dan L = toluena-3,4-ditiolat (L1), 1,2-benzenaditiolat
(L2), 3,6-dikloro-1,2-benzenaditiolat (L3), telah dikaji untuk dijadikan pemeka foto bagi elektrod anod untuk sel fotoelektrokimia. Kompleks tungsten nitrosilditiolena disintesiskan dan diciri dengan menggunakan spektroskopi (IR) dan ultra-lembahyung dan cahaya nampak (UV-Vis) dan analisis mikro unsur CHNS. Teknik voltametri berkitar (CV) telah digunakan untuk menentukan keupayaan redoks kompleks dan seterusnya aras jalur tenaga telah ditentukan daripada data yang diperoleh. Ketiga-tiga kompleks menunjukkan jurang jalur tenaga dalam julat 1.59 – 1.63 eV. Jurang jalur tenaga yang dikira daripada analisis CV adalah bersepadan dengan anggaran daripada spektrum serapan elektronik kompleks. Berdasarkan gambar rajah jalur tenaga, ketiga-tiga kompleks dijangka mempunyai potensi untuk digunakan sebagai pemeka foto bagi fotoelektrod sel fotoelektrokimia.
Kata kunci: Pemeka foto; sel fotoelektrokimia; tungsten nitrosilditiolena
ABSTRACT
The
chemical and physical properties of tungsten nitrosyldithiolene complexes with a general formulae of [WTp*(NO)(L)]
where Tp* = tris(3,5-dimethylpyrazolyl)hidroborate and L = toluene 3,4-dithiolate (L1),
1,2-benzenedithiolate (L2), 3,6-dichloro-1,2-benzenedithiolate (L3), have been
studied for application as a photosensitizer in an anode for photoelectrochemical cell. These complexes were synthesized
and characterised by infrared (IR),
ultraviolet-visible (UV-Vis) spectroscopy and CHNS micro elemental analysis.
Cyclic voltammetry (CV) was used to determine their redox potentials and their
band energies were calculated from the potentials obtained. All three complexes
showed energy band gaps in the range of 1.59 – 1.63 eV.
The calculated band gaps from CV analyses were comparable with the estimated values
obtained from the UV-Vis absorption data. Based on the postulated band diagram,
these complexes may be a potential photosensitizer to be used in the photoeletrodes for photoelectrochemical cells.
Keywords: Photoelectrochemical cell; photosensitizer; tungsten nitrosyldithiolene
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*Pengarang untuk surat-menyurat; email: mbkassim@ukm.my
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