多層次的二氧化鈦/二氧化釕奈米柱複合結構被合成出來：利用射頻濺鍍在矽基材上長出二氧化釕奈米柱，接這在其上用旋轉塗佈法塗佈無晶相的二氧化鈦層，在乙酸液熱反應底下，這層無晶相層會轉變成特殊形貌的鈦酸鹽類，再經過700 oC持溫1小時的退火動作，鈦酸鹽類會轉變成anatase相的二氧化鈦，並且不改變形貌。我們可以得到亞微米顆粒、花狀和奈米顆粒三種不同形貌的二氧化鈦。
不同型貌的多層次二氧化鈦/二氧化釕奈米柱複合結構可以當作在光電化學水分解的光陽極，所使用的電解液為1 M KOH，在氙燈照射下，電壓0.2 V vs.Ag/AgCl時，花狀二氧化鈦可以測到的光電流增益為2.20 mA/cm2，二氧化鈦奈米顆粒可測到1.16 mA/cm2，二氧化鈦亞微米顆粒可測到1.48 mA/cm2。
但是，量測不同厚度的花狀二氧化鈦二氧化釕奈米柱複合結構的光電流增益，當厚度大於6 μm，光電流增益和穩定性會有明顯的下降，因此我們推測最佳厚度可能在2 μm附近，花狀二氧化鈦在三個形貌中表現最好。在光電化學水分解中，多層次二氧化鈦/二氧化釕奈米柱是依很有潛力的光陽極。

Hierarchical TiO2 / RuO2 nanorod heterostructure was synthesized. Amorphous TiO2 layer was firstly spin-coated onto RuO2 nanorods on Si wafer prepared by RF sputtering. The amorphous layer was transformed to titanate with special morphology under acetic acid solvothermal reaction. After heating at 700 oC for 1 h, the titanate further transfer to anatase without morphology change. Three kinds of morphology of TiO2 were synthesized, including submicron-particle, flower-like, and nanoparticles.
Furthermore, the varied-morphologied TiO2 / RuO2 nanorods heterostructure was used as working electrode for photoelectrochemical water splitting in 1 M KOH aqueous solution. It showed larger photocurrent enhancement (2.20 mA/cm2 at 0.2 V vs Ag/AgCl) compared with that of TiO2 nanoparticles / RuO2 nanorods (1.16 mA/cm2 at 0.2 V vs Ag/AgCl) and that of TiO2 submicron-particles (1.48 mA/cm2 at 0.2 V vs Ag/AgCl) under the irradiation of a Xe lamp.
However, the photocurrent enhancement and photostability of TiO2 / RuO2 nanorod heterostructure with varied thickness drop largely when the thickness of the sample exceeds 6 μm. From the outcome above, the optimum thickness is around 2 μm, and the performance of flower-like TiO2 is the best among the three morphologies. These suggest the hierarchical heterostructure that TiO2 flower / RuO2 nanorods can be employed as a potential photoanode for photoelectrochemical water splitting.

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