改質二氧化鈦奈米管光催化裂解水產氫之研究

Modification of Titania nanotube for Hydrogen Generation from photocatalytic splitting water

詹晉豪(Chin-Hao Chan)

指導教授 ： 王宏文

中原大學/理學院/化學研究所/碩士(2013年)

https://doi.org/10.6840/CYCU.2013.00146

摘要

本研究利用震盪化學浴沉積法(Chemical Bath Deposition, CBD)將硫化鎘(CdS)及三氧化二鐵(Fe2O3)均勻複合到二氧化鈦奈米管陣列(Titania Nanotube Arrays, TNA)上，探討複合對光催化活性之影響，並將其應用於光催化水解產氫上。由於複合CdS缺乏可見光長波長部分的吸收能力，且產氫效率較不穩定，因此藉由共複合能隙值較低的Fe2O3，以期改善吸收特性及產氫穩定性。結果顯示共複合有長波長區域的吸收，且在8小時內有穩定的產氫效率，其產氫效率分別為12 mlcm-2h-1(Fe2O3/CdS)及1.54 mlcm-2h-1(CdS/Fe2O3)，可看出共複合Fe2O3/CdS效率值較TNA-blank(2.43 mlcm-2h-1)高約5倍，但共複合CdS/Fe2O3效率卻較TNA-blank低。藉由測量半導體界面間反應的費米能階變化作機制推導可看出，共複合Fe2O3/CdS的階梯狀結構有利於電子及電洞的傳導，但共複合CdS/Fe2O3的相反結構則容易導致電子電洞再結合，因此共複合Fe2O3/CdS有較好的光電流值及產氫效率。

關鍵字

產氫 ； 奈米管陣列 ； 硫化鎘 ； 二氧化鈦 ； 三氧化二鐵

並列摘要

CdS and Fe2O3-sensitized TiO2 nanotube arrays (TNA) was fabricated by inserting CdS and Fe2O3 nanoparticles into TNA via ultrasonic-assisted chemical bath deposition, and its effect on photocatalytic properties and hydrogen generation rate were discussed in this study. CdS-sensitized TNA lacked of absorption on long wavelength region and stability on hydrogen generation, so we used Fe2O3 which has lower bandgap to improve absorption properties and hydrogen generation efficiency. The results show that co-sensitized TNA had good apsortion ability on long wavelength region and good stability in eight hours hydrogen generation experiment. The hydrogen generation rate for Fe2O3/CdS and CdS/Fe2O3 were 12 and 1.54 mlcm-2h-1. The rate of hydrogen generation for Fe2O3/CdS was five times higher than TNA-blank(2.43 mlcm-2h-1), but CdS/Fe2O3 had lower hydrogen generation efficiency. The mechanism derivation was designed by measuring the shift of the Fermi level of two semiconductors due to their contact. Co-sensitized Fe2O3/CdS had stepwise structure and is advantageous to transition for excited electrons and holes, but CdS/Fe2O3 had a reverse structure which results in recombination of electron and hole. Therefore, Fe2O3/CdS had better photocurrent performance and hydrogen generation rate.

並列關鍵字

hydrogen generation ； CdS ； Fe2O3 ； titania ； nanotube arrays

參考文獻

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