Reduced N/Ni-doped TiO₂ nanotubes photoanodes for photoelectrochemical water splitting

Abstract

This work reports the facile synthesis of reduced N/Ni-doped TiO2 nanotubes photoanodes and their photocatalytic activity application.

Photoelectrochemical Water Splitting Properties of Ti-Ni-Si-O Nanostructures on Ti-Ni-Si Alloy

“…It was calculated that the flat-band potential was −0.625 V (vs. Ag/AgCl). The carrier concentration was in the range of 2.13 × 10 16 /cm 3 to 8.57 × 10 16 /cm 3 for Ti-Ni-Si-O photoanodes, which was comparable with those of pure TiO 2 photoanodes [ 23 ]. Simelys et al [ 38 ] reported that a higher carrier concentration could facilitate the charge separation at the semiconductor-electrolyte interface, and the carrier concentration reached up to 7.05 × 10 19 /cm 3 for the TiO 2 nanotubes with a thickness of about 1.5 μm.…”

“…Therefore, modification strategies including foreign element doping, surface decoration, and sensitization with dye have been adopted to overcome these drawbacks over the last 30 years [ 11 , 12 , 13 , 14 , 15 , 16 ]. One of the most studied methods is the doping of TiO 2 materials with metal ions or nonmetallic elements such as Ni, Ta, Nb, Fe, Zn, C, N, and so on [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ].…”

Influences of Doping on Photocatalytic Properties of TiO2 Photocatalyst

“…Other N and metal codoping also includes (N, Ni) codoping [301], (N, Bi) codoping [302], (N, V) codoping [303], and (N, Mo) codoping [304]. Liu et al reported the facile synthesis of reduced (N, Ni) codoped TiO 2 nanotubes and their photocatalytic activity application [301]. The narrowed bandgap of TiO 2 due to the doping of N and Ni elements could enhance the light absorption effectively.…”

Ni/Si-Codoped TiO2 Nanostructure Photoanode for Enhanced Photoelectrochemical Water Splitting

“…One is the relatively large intrinsic band gap (3.2 eV for anatase and 3.0 eV for rutile), resulting in an inefficient utilization of solar energy [5]. The other is the high recombination rate of photogenerated electrons and holes in the TiO 2 nanostructure, which inhibits the migration of photogenerated electrons and holes to the surface of the photocatalyst [6].…”

“…Anodization of multicomponent titanium alloy can not only dope foreign elements in TiO 2 but also modify TiO 2 nanostructures. In our previous works, we have reported the fabrication of Ni-doped TiO 2 and Si-doped TiO 2 [6,12,21], but few works have been reported on the fabrication of Ni/Si-codoped TiO 2 and the relevant PEC properties. In this work, we successfully fabricated Ni/Si-codoped TiO 2 nanostructures by anodizing Ti-Ni-Si ternary alloy.…”