Synthesis and characterization of 1-D gallium oxide/ 2-D reduced graphene oxide heterostructures

• Main Authors: Yu-Jie Huang, 黃昱傑
• Other Authors: Li-Chia Tien
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/5p9m47

碩士 === 國立東華大學 === 材料科學與工程學系 === 106 === The synthesis and characterization of 1-D gallium oxide / 2-D reduced graphene oxide (β-Ga2O3/r-GO) heterostructures were studied in this work. The graphene oxide (GO) was firstly synthesized by a modified Hummers method, and the GO solution was dispersed on thermally grown silicon dioxide (SiO2) substrates by spin coating and drop casting. The β-Ga2O3 nanostructures were grown on GO/SiO2 substrates by vapor transport. The results show that samples synthesized with Au catalysts were proceed by VLS mechanism, the obtained nanowires were twisting and with smaller diameters. For samples those were directly grew on GO/SiO2 substrates, the obtained products were nanoparticles and nanorods. Moreover, the density and distribution of GO on the SiO2 substrate also affect the growth behavior of the nanostructures, such as growth rate, surface morphologies, density, and distribution of nanostructures. We also study the effects of growth conditions on the growth of nanostructures. Structural characterization results show samples grown by VLS and VS mechanism were both monoclinic structure. The samples grown by VLS mechanism are with preferred orientation of [¯101], while the samples grown by VS mechanism are with preferred orientation of [111]. The GO was reduced to r-GO during the growth, suggesting the samples were β-Ga2O3/r-GO heterostructures confirmed by surface analysis results. The Raman spectra reconfirmed the formation of r-GO, the ID/IG ratio increased after formation of β-Ga2O3/r-GO, indicating the growth of β-Ga2O3 on GO introduce defects in the 2-D structures. For optical properties, the PL emission of β-Ga2O3/r-GO samples show a decreased luminescence property, suggesting quenching effect exist in heterostructures. It was also observed that the degradation rate of β-Ga2O3/r-GO sample is significantly higer than that of β-Ga2O3 nanowires. The results suggest β-Ga2O3/r-GO heterostructures exhibit a longer lifetime of photo-induced charge carriers and further increase its photocatalytic activity.