Fabrication of Hierarchical TiO₂Nanotubes in a New HBF₄-Based Electrolyte for Enhanced Morphology and Photocatalytic Activities

Abstract

The present work introduces a new HBF 4 -based electrolyte for the preparation of anodic TiO 2 nanotubes (NTs). It is shown that, by optimizing the preparation parameters, highly ordered and extremely smooth TiO 2 NTs can be successfully fabricated in the HBF 4 -containing electrolyte via a two-step anodization approach (so-called the BF 4 −TiO 2 NTs). The obtained BF 4 −TiO 2 NTs have unique hierarchical upper-nanopore/lower-nanotube structure and show both enhanced photoelectrochemical and photocatalytic performances than the referenced TiO 2 NTs formed in the F − -containing electrolyte (i.e., the F−TiO 2 NTs). We consider that the decomposition of BF 4 − into F − under high electric field is the key for the formation of anodic BF 4 −TiO 2 NTs, and this allows the growth of BF 4 −TiO 2 NTs going through a quite different way as compared to that of the F−TiO 2 NTs. These findings may pave an alternative way for the preparation of TiO 2 NTs with enhanced geometrical features and application properties.

Microwave-assisted preparation of self-doped TiO2 nanotube arrays for enhanced photoelectrochemical water splitting

“…2, XRD diffraction peaks located at 25.3 , 37.8 , 47.9 , and 54.0 suggest that the annealed TNTs are highly crystallized with pure anatase phase. 26,27 Aer the microwave-assisted chemical reduction, the MR-TNTs also exhibit strong anatase diffraction, but a close observation of the XRD pattern in the range of 20 to 30 reveals a broad peak centered at 20.8 and a sharp peak located at 27.2 (inset of Fig. 2).…”

Electrodeposition of ultrathin nickel–cobalt double hydroxide nanosheets on nickel foam as high-performance supercapacitor electrodes

“…1a). The O 1s XPS spectrum can be divided into two small peaks, in which the main peak at around 531.1 eV is attributed to hydroxide groups (OH À ), 25,28 revealing the formation of metallic hydroxides (Fig. 1b).…”

Barrier-oxide layer engineering of TiO2 nanotube arrays to get single- and multi-stage Y-branched nanotubes: Effect of voltage ramping and electrolyte conductivity

“…A better degree of control of the nanotube array architecture will expose tunable and functional properties, for example controlling the texture and surface area can enhance light absorption properties [10,11]. TNAs with special morphologies have attracted great interests in many fields because of their novel properties which can largely be incorporated into nano devices [12][13][14][15][16][17][18][19][20]. Modulating the surface morphology of TNAs is a key factor to enlarge the specific surface area of the nanotubes, which leads to better interfacial applications, like improved performance of dye-sensitized solar cells (DSSC), better catalytic, electrochemical and gas sensing properties, among others [21][22][23][24].…”