電漿電解氧化製備多孔奈米晶粒二氧化鈦膜及其性質

本研究使用電漿電解氧化法在酸性及鹼性電解液於鈦基材上皆可製備出多孔奈米晶粒之二氧化鈦膜。酸性電解液使用0.5 M磷酸，鹼性電解液分別為0.03 M磷酸鈉溶液及0.3 M碳酸鈉溶液。實驗結果顯示電解液成分及電壓對鍍膜之結晶結構及孔洞結構影響很大。鹼性電解液中0.03 M磷酸鈉溶液形成的鍍膜是銳鈦礦相，而使用0.3 M碳酸鈉溶液卻是形成金紅石相。金紅石相形成分散之圓形孔洞且在孔洞之間有裂紋存在。磷酸鈉溶液中形成分散獨立之圓形孔洞但在孔洞之間並無裂紋存在，磷酸鈉溶液形成之孔洞結構晶粒尺寸約在50 nm，表面粗度約在0.45μm，結果顯示低濃度磷酸鈉作為電解液具有平整的表面是一種具環保的鍍膜製程，腐蝕試驗結果顯示經PEO製程所形成之鍍膜具有極低之腐蝕電流密度。

關鍵字

二氧化鈦；電漿電解氧化；金紅石；銳鈦礦；表面粗度

並列摘要

Porous nanocrystalline titania films were synthesized on the Ti plates in acid or base solution by plasma electrolytic oxidation. Using 0.5 M phosphoric acid ( H_3PO_4 ) as acid electrolyte and 0.3 M sodium carbonate (Na_2CO_3) or 0.03 M sodium phosphate (Na_3PO_4) as alkaline electrolyte. The experimental results indicated that the composition of electrolyte and voltage magnitudes have significant effects on the crystalline structure and pores structure. Using 0.3 M Na_2CO_3 as electrolyte, rutile phase films are grown on titanium plates. Cracks are found between pores while anatase phase films were synthesized by 0.03 M Na_3PO_4. The pore structure of Na_3PO_4 exhibits separately distributed circle-shaped pores. However, The grain size of as-grown films was measured about 50 nm and the roughness was about 0.5 μm. The results show dilute concentrations of Na_3PO_4 as the electrolyte exhibits more smooth surface coating. Therefore, PEO is an environmentally friendly process. Corrosion test results showed that the coating formed by the process of PEO demonstrate extremely low corrosion current density.

並列關鍵字

Titania(TiO_2) ； plasma electrolytic oxidation ； anatase ； rutile ； roughness

參考文獻

He, Z.,Cai, Q.,Fang, H.,Situ, G.,Qiu, J.,Song, S.,Chen, J.(2013).Photocatalytic activity of TiO2 containing anatase nanoparticles and rutile nanoflower structure consisting of nanorods.Journal of Environmental Sciences.2460-2468.