Interfacial Charge Carrier Dynamics of GaOOH-Au Nanoheterostructures

• Main Authors: Hsu, Yi-Han, 許逸涵
• Other Authors: Hsu, Yung-Jung
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/66038472245764664877

碩士 === 國立交通大學 === 材料科學與工程學系 === 100 === Due to the photo-induced charge separation property, semiconductor-metal nanoheterostructures have been extensively applied in many photoelectric conversion processes including photovoltaics, photocatalysis and water splitting. In this work, a facile wet-chemistry chemical precipitation approach was deveopled to prepare GaOOH nanorods (NRs) with considerable uniformity in size. It was found that the pH value of reaction solution as well as the addition of MgSO4 greatly influenced the morphology of the resultant GaOOH. To further the charge separation efficiency of GaOOH, Au nanoparticles were deposited on the surface of GaOOH NRs with a chemical reduction method. By modulating the concentration of HAuCl4 employed, the amount of Au nanoparticles decorated on GaOOH NRs can be readiy controlled. Owing to the difference in band structure between GaOOH and Au, the photoexcited electrons of GaOOH would preferentially transfer to Au, leaving photogenerated holes in GaOOH to achieve charge carrier separation. The result of steady-state photoluminescence analysis IV confirms the enhancement in charge separation efficiency for GaOOH NRs upon the deposition of Au nanoparticles. Among the different samples, GaOOH-Au with 1.0 mol% of Au was found to show the most significant charge separation efficiency. Time-resolved photoluminescence spectra were measured to quantitatively analyze the electron transfer event between GaOOH and Au. As compared to the relevant commercial products like P-25 TiO2 and Ga2O3 powders, the as-synthesized GaOOH-Au sample exhibited superior photocatalytic performance toward methanol oxidation, attributable to the effective charge separation that took place at the interface of GaOOH-Au. The current GaOOH-Au sample may find potential applications in relevant photocatalytic reactions such as water splitting and photoexcited electron storage.