摘要
Ta4N5是熱力學中高N含量的穩定相，然而，Ta4N5沒有獲得太多的關注，與Ta3N5比較，特別是以濺鍍法的製程。從我們的研究中，發現Ta4N5的能隙接近2.5電子伏特，可有效地利用可見光範圍接近500奈米，運用在光催化應用是相當有潛力。
本研究中，是利用直接濺鍍Ta4N5 奈米柱在FTO基材上及研究其的光活性之應用。藉由調整Ar/N2比的參數獲得，濺鍍槍和基材的工作距離，濺射壓力和直流電源大小來獲得多晶且良好分裂程度的陣列式Ta4N5的奈米柱。利用各種分析工具，例如XRD，SEM，TEM和UV-VIS用來研究其特性。
研究光降解的程度。無論在pH=10中600 C和550 C樣品顯示出比在pH = 7的降解速度快約2倍。在可見光的照射與0.5 V電位下其600 C樣品的光化學電流大約4 A/cm2, Ta4N5奈米柱經過七個週期和三次的循環測試顯現出色的穩定性。而600 C的樣品中IPCE量測值約3％，且IPCE變化趨勢是波長的函數並且發現與UV-VIS吸收光譜一致。
未來工作的研究包括推行下列各項：具有優良結晶度與較好的分離程度Ta4N5奈米柱，奈米柱Ta3N5結構，各種陽離子摻雜，並分解水獲得氫氣燃料。

Abstract
Ta4N5 is N-rich thermodynamically stable phase, however, Ta4N5 did not obtain much attention, comparing with Ta3N5, especially using sputtering. From our research, the band gap of Ta4N5 is approximate 2.5 eV that can effectively utilize the visible light up to 500 nm, which is promising for photocatalysis.
In this research, reactive sputtering was used to directly grow Ta4N5 nanorod arrays on a FTO substrate for the photo-related applications. Well separated and polycrystalline Ta4N5 nanorod arrays were obtained by tuning the parameters of the Ar/N2 ratio, the working distances between the gun and the substrate, the sputtering pressures, and the DC power. Various characterization tools such as XRD, SEM, TEM, and UV-VIS were used to study the properties.
The photodegradation performance was studied. Both in-situ 600 C and 550 C samples showed a considerable improvement under the environment at pH = 10, approximately 2 times faster than that measured at pH = 7. The photoelectrochemical current for the in-situ 600 C samples was measured approximate 4 A/cm2 under visible light illumination at the constant bias supply at 0.5 V. The IPCE of the in-situ 600C sample was found approximately 3% and the IPCE variation trend as a function of wavelength was found in a good agreement with the UV-VIS absorption spectrum. Ta4N5 nanorods showed excellent stability after a cycling test consisting of three runs and seven cycles for each run.
The future works for this research include pursuing the followings: much better separation of Ta4N5 nanorods with excellent crystallinity, Ta3N5 nanorod structures, various cation dopings, and water splitting to obtain H2 fuels.

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