Electrochemical and photoelectrochemical activity of laser modified semitransparent nanotubes formed out of AuTi layers and titania nanotubes decorated with gold nanoparticles

This is the authors' abstract. We don't add key points for this paper.

• Two types of semitransparent laser-treated oxide nanotubes with embedded Au. • Highest photocurrent density achieved for gold-coated nanotubes treated with laser. • Laser-treated Ti/Au oxide nanotubes show enhanced current density. • Improved redox activity in Ti/Au oxide nanotubes compared to bare titania. Two types of novel semitransparent titania nanotube (TiNT) materials were fabricated using two protocols, i.e. laser treated: a) titania nanotubes covered with thin gold layer and b) oxide nanotubes produced out of titanium-gold co-deposited layers. SEM images and secondary ion mass spectroscopy measurements revealed the formation of well-distributed Au nanoparticles in the TiNT matrix due to laser irradiation and the optimized laser parameters used for the material modification were identified based on the electrochemical behavior of the samples. The electrochemical tests of both types of electrodes were performed and the highest photocurrent density of 13 µAcm -2 recorded at +0.8 V for the electrode material prepared according to a) route and treated with 80 mJcm -2 laser energy fluence is 6.5 times higher than photocurrent density recorded for bare titania material (2 µAcm -2 ) and 4.3 times higher than the same electrode material without laser treatment (3 µAcm -2 ). On the other hand, electrode material fabricated according to protocol b) shows an enhanced current density of 0.93 mAcm -2 under anodic polarization when the material was treated with 20 mJcm -2 laser energy fluence comparing to bare titania (0.22 mAcm -2 ). Moreover, the latter electrode exhibits redox behavior similar to the gold disc electrode and higher space charge capacitance compared to bare titania material.