Enhanced Photoelectrochemical Water Splitting Performance of Ni/Si-doped TiO₂ Photoanode Fabricated through Electrochemical Reduction in Aqueous Solutions

Abstract

Ni/Si-doped TiO2 nanostructures were prepared by anodizing Ti-1Ni-5Si alloy. The electrochemical reduction in the aqueous solutions was a simple and effective method to self-dope Ti3+ into Ni/Si-doped TiO2 nanostructures. It was found that electrochemical reduction in neutral aqueous solution (pH 7) was more effective than that in either acidic aqueous solution (pH 3) and basic aqueous solution (pH 13). The stable reduced Ni/Si-doped TiO2 photoanode obtained in the neutral aqueous solution exhibited an excellent photoelectrochemical water splitting performance due to the increased Ti3+ and oxygen vacancies species, which not only extended the visible-light absorption range but also promoted the charge transfer and separation process. A remarkable photocurrent density of 2.41 mA cm−2 at 0 V vs Ag/AgCl was achieved, corresponding to a photoconversion efficiency of 1.12%, which was 5.9 times that of the undoped TiO2 photoanode (0.19%).

Recent progress on post-synthetic treatments of photoelectrodes for photoelectrochemical water splitting

“…In addition, it was proved that electrochemical reduction could induce a type II structure, which enhances charge separation and transport 78 as well as creates self-doped Ti 3+ accompanied by increasing the amount of O vac in the TiO 2 photoanode. [79][80][81] These studies validate that electrochemical treatments not only can affect the surface/ interface properties of TiO 2 , but also improve its bulk attributes from time to time.…”

Enhancement of Electrochemical Properties of Lithium Rich Li2RuO3 Cathode Material

“…They found that Cr doping increases capacity and Na doping suppresses voltage-decay. Similar doping investigations using Mg, [24][25][26] Ni, [25][26][27][28][29][30][31][32][33][34][35] Co, 28,31,36,37 and N [38][39][40] on the electrode of lithium-ion batteries have demonstrated improved electrochemical performance.…”

Effects of Si Slabs on the Performance of CdO Thin Films Designed for Optoelectronic Applications

“…Such behavior was assigned to the many-body effects which are known causing shifting up of the valence band and shifting down of the conduction band resulting in the band gap shrinkage 8 . Narrowing the energy band gap upon Si doping was also assigned to the lattice shrinkage caused by the stronger electronegativity of Si (1.80) 32 over that of Cd (1.69).…”