標題: Enhanced Photocatalytic Performance of Nitrogen-Doped TiO2 Nanotube Arrays Using a Simple Annealing Process
作者: Phuoc Huu Le
Le Trung Hieu
Tu-Ngoc Lam
Nguyen Thi Nhat Hang
Nguyen Van Truong
Le Thi Cam Tuyen
Pham Thanh Phong
Leu, Jihperng
材料科學與工程學系
Department of Materials Science and Engineering
關鍵字: N-doped TNAs;two-step anodization;photocatalytic activity;thermal annealing;modified TiO2;band gap
公開日期: 1-Dec-2018
摘要: Nitrogen-doped TiO2 nanotube arrays (N-TNAs) were successfully fabricated by a simple thermal annealing process in ambient N-2 gas at 450 degrees C for 3 h. TNAs with modified morphologies were prepared by a two-step anodization using an aqueous NH4F/ethylene glycol solution. The N-doping concentration (0-9.47 at %) can be varied by controlling N-2 gas flow rates between 0 and 500 cc/min during the annealing process. Photocatalytic performance of as-prepared TNAs and N-TNAs was studied by monitoring the methylene blue degradation under visible light ( 400 nm) illumination at 120 mWcm(-2). N-TNAs exhibited appreciably enhanced photocatalytic activity as compared to TNAs. The reaction rate constant for N-TNAs (9.47 at % N) reached 0.26 h(-1), which was a 125% improvement over that of TNAs (0.115 h(-1)). The significant enhanced photocatalytic activity of N-TNAs over TNAs is attributed to the synergistic effects of (1) a reduced band gap associated with the introduction of N-doping states to serve as carrier reservoir, and (2) a reduced electronhole recombination rate.
URI: http://dx.doi.org/10.3390/mi9120618
http://hdl.handle.net/11536/148678
ISSN: 2072-666X
DOI: 10.3390/mi9120618
期刊: MICROMACHINES
Volume: 9
Appears in Collections:Articles