Growth and Structural Properties of ZnO-SWCNTs Produced by Chemical Bath Deposition and Sol-Gel Methods

Abstract

Two different methods were used to synthesize and fabricate zinc oxide-carbon nanotubes (ZnO-CNTs) thin films; chemical bath deposition (CBD) and sol-gel method. Single-walled carbon nanotubes (SWCNTs) were implemented in preparing the thin films. The obtained thin films were annealed in air at different temperatures levels of 200 °C, 250 °C, 300 °C and 350 °C for 30 min. Both methods successfully grew various nanostructures of ZnO-CNTs such as nanoparticles, nanobranches and nanoflakes. The synthesized nanostructures were characterized by using field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The crystallite sizes were calculated between 38.54 nm and 6.13 nm. FESEM cross sectional images indicated the thin film thicknesses varied from 164.9 μm to 5.84 μm. The TEM images estimated the diameters of the SWCNTs in the range of 3.38 nm to 16.14 nm. TEM images also proved the presence of ZnO entangled between SWCNTs. A combination of ZnO and SWCNTs in the thin film proposes a simple and low cost CBD method to produce various ZnO-CNTs nanostructures with appropriate thickness. Keywords: zinc oxide; carbon nanotubes; nanostructures; thin film ABSTRAK Dua kaedah telah digunakan untuk mensintesiskan serta memfabrikasi filem nipis zink oksida-karbon nanotiub (ZnO-CNTs); kaedah pemendapan kubang kimia (CBD) dan sol-gel. Karbon-nanotiub berdinding satu (SWCNTs) telah digunakan dalam penyediaan filem nipis. Filem nipis yang diperolehi disepuh-lindap melalui udara pada tahap suhu yang berbeza dari 200 °C, 250 °C, 300 °C dan 350 °C selama 30 minit. Kedua-dua kaedah telah berjaya menumbuhkan pelbagai struktur nanoZnO-CNTs seperti nanozarah, nanodahan dan nanokepingan. Pencirian struktur nanoitu dilakukan menggunakan mikroskop elektron imbasan (FESEM), belauan sinar-X (XRD) dan mikroskop electron pancaran (TEM). Saiz kristal yang dikira adalah antara 38.54 nm dan 6.13 nm. Analisis bagi keratan rentas FESEM imej menunjukkan ketebalan filem yang pelbagai dari 164.9 μm sehingga 5.84 μm. Imej TEM menganggarkan diameter karbon nanotiub dalam julat 3.38 nm sehingga 16.14 nm. Imej TEM turut mengesahkan kewujudan ZnO yang melekat di antara CNTs. Kombinasi ZnO dan SWCNTs di dalam filem nipis mencadangkan penggunaan kaedah CBD yang ringkas dan berkos murah untuk menghasilkan pelbagai struktur ZnO-CNTs bersaiz nanodengan ketebalan yang sesuai. Kata-kata kunci: zink oksida; karbon nanotiub; struktur bersaiz nano; filem nipis