Structure and visible photocatalytic activity of nitrogen-doped meso-porous TiO2 layer on Ti6Al4V substrate by plasma-based ion implantation
(1. School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China;
2. Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China;
3. Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China)
2. Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China;
3. Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050, China)
Abstract: The nitrogen-doped porous TiO2 layer on Ti6Al4V substrate was fabricated by plasma-based ion implantation of He, O and N. In order to increase the photodegradation efficiency of TiO2 layer, two methods were used in the process by forming mesopores to increase the specific surface area and by nitrogen doping to increase visible light absorption. Importantly, TiO2 formation, porosity architectures and nitrogen doping can be performed by implantation of He, O and N in one step. After implantation, annealing at 650 ℃ leads to a mixing phase of anatase with a little rutile in the implanted layer. By removing the near surface compact layer using argon ion sputtering, the meso-porous structure was exposed on surfaces. Nitrogen doping enlarges the photo-response region of visible light. Moreover, the nitrogen dose of 8×1015 ion/cm2 induces a stronger visible light absorption. The photodegradation of rhodamine B solution with visible light sources indicates that the mesopores on surfaces and nitrogen doping contribute to an apparent increase of photocatalysis efficiency.
Key words: Ti6Al4V alloy; TiO2 layer; nitrogen doping; ion implantation; structure; photocatalytic activity