TY - JOUR
T1 - Characterization of Sputtered HfO2−x–TiO2−x Nanocolumn Arrays and Their Application in Photocatalysis
AU - Feng, Hao Che
AU - Chang, Kao Shuo
N1 - Funding Information:
This work was partly supported by the Ministry of Science and Technology, Taiwan, under Grants MOST 102-2221-E-006-073 and MOST 102-2633-E-006-001.
PY - 2017/7/1
Y1 - 2017/7/1
N2 - The physical and chemical properties of sputtered HfO2−x–TiO2−x nanocolumn arrays and the photocatalytic action of high-ε (HfO2) nanocolumns for decomposition of methylene blue have been studied. Fabrication of HfO2−x–TiO2−x nanocolumn array composites by reactive sputtering without further treatment was comprehensively investigated. Well-isolated HfO2−x nanocolumns with maximum separation of approximately 500 nm and excellent orientation normal to the substrate were obtained. The coupling between HfO2−x and TiO2−x was found to be crucial for enhanced photocatalytic action; the optimal coupling was identified for HfO2−x–TiO2−x nanocolumn composites with four pairs of alternating layers, which showed better performance (by approximately 25%) under 30 W of ultraviolet (UV) irradiation, compared with TiO2−x thin films. The synergistic photocatalytic effect was predominantly attributed to defect-induced electron migration along the HfO2−x nanocolumn structure. In addition, the corresponding photoluminescence spectra and energy band diagram for the HfO2−x–TiO2−x system were used to complement the photocatalytic results.
AB - The physical and chemical properties of sputtered HfO2−x–TiO2−x nanocolumn arrays and the photocatalytic action of high-ε (HfO2) nanocolumns for decomposition of methylene blue have been studied. Fabrication of HfO2−x–TiO2−x nanocolumn array composites by reactive sputtering without further treatment was comprehensively investigated. Well-isolated HfO2−x nanocolumns with maximum separation of approximately 500 nm and excellent orientation normal to the substrate were obtained. The coupling between HfO2−x and TiO2−x was found to be crucial for enhanced photocatalytic action; the optimal coupling was identified for HfO2−x–TiO2−x nanocolumn composites with four pairs of alternating layers, which showed better performance (by approximately 25%) under 30 W of ultraviolet (UV) irradiation, compared with TiO2−x thin films. The synergistic photocatalytic effect was predominantly attributed to defect-induced electron migration along the HfO2−x nanocolumn structure. In addition, the corresponding photoluminescence spectra and energy band diagram for the HfO2−x–TiO2−x system were used to complement the photocatalytic results.
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U2 - 10.1007/s11664-017-5434-8
DO - 10.1007/s11664-017-5434-8
M3 - Article
AN - SCOPUS:85015923556
VL - 46
SP - 4532
EP - 4538
JO - Journal of Electronic Materials
JF - Journal of Electronic Materials
SN - 0361-5235
IS - 7
ER -