TiO2 Nanotubes on Transparent Substrates: Control of Film Microstructure and Photoelectrochemical Water Splitting Performance

Abstract

Abstract:Transfer of semiconductor thin films on transparent and or flexible substrates is a highly desirable process to enable photonic, catalytic, and sensing technologies. A promising approach to fabricate nanostructured TiO 2 films on transparent substrates is self-ordering by anodizing of thin metal films on fluorine-doped tin oxide (FTO). Here, we report pulsed direct current (DC) magnetron sputtering for the deposition of titanium thin films on conductive glass substrates at temperatures ranging from room temperature to 450 • C. We describe in detail the influence that deposition temperature has on mechanical, adhesion and microstructural properties of titanium film, as well as on the corresponding TiO 2 nanotube array obtained after anodization and annealing. Finally, we measure the photoelectrochemical water splitting activity of different TiO 2 nanotube samples showing that the film deposited at 150 • C has much higher activity correlating well with the lower crystallite size and the higher degree of self-organization observed in comparison with the nanotubes obtained at different temperatures. Importantly, the film showing higher water splitting activity does not have the best adhesion on glass substrate, highlighting an important trade-off for future optimization.

Titanium Dioxide Photocatalysis

“…A promising approach to fabricate nanostructured TiO 2 films on transparent substrates is self-ordering by the anodizing of thin metal films on fluorine-doped tin oxide (FTO) coupling pulsed direct current (DC) magnetron sputtering for the deposition of titanium thin films on conductive glass substrates and anodization and annealing for the TiO 2 nanotube array [13]. Zelny et al reported a detailed investigation of mechanical and adhesion properties of Ti films sputtered at different temperatures, showing that a more active TiO 2 nanotube sample towards photoelectrochemical water splitting was obtained from a Ti substrate sputtered at 150 • C, showing the lowest crystallite size, best degree of self-organization, and enhanced charge transfer at the semiconductor/liquid interface.…”

Dry Hydrogen Production in a Tandem Critical Raw Material-Free Water Photoelectrolysis Cell Using a Hydrophobic Gas-Diffusion Backing Layer

“…The existence of several concerns related to the increasing energy demand and the related environmental crisis [1][2][3][4][5][6] indicates the need to identify innovative, effective and low cost solutions. Photoelectrochemical water splitting (PWS) [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] is recognised as a promising strategy and it attracts particular interest for storing solar energy into the chemical bonds of hydrogen as fuel [26][27][28], which can be further utilised in fuel cells [29][30][31][32][33][34], internal combustion engines and to progressively decarbonize industrial processes [35][36][37][38][39].…”

One Pot Microwave Irradiation Synthesis of Spherical and Nanotube Titanates Incorporated Reduced Graphene for Efficient Hydrogen Production Photo-Electrocatalytically

“…Constructively, our cost effective photocatalyst 50TNT-50GO has shown superior photoelectrocatalytic water splitting performances (9.2 mA cm -2 ) compared to others in literatures such as various black titania either produced via reduction by CaH 2 (1.99 mA cm -2 ) or Mg metal (3.1 mA cm -2 ) [19][20]. It also exceeds those of the ternary structured Ag/TiO 2 /CNT (0.9 mA cm -2 ), TiO 2 @RG (6.0 mA cm -2 ), reduced graphenegraphene oxide nanohybrid (61.35 μA/cm 2 ) and controlled lm of TiO 2 nanotubes (175 µA cm −2 ) [21][22][23][24] all performed in the same electrolyte.…”