Electrochemically Faceted Bamboo‐type TiO₂ Nanotubes Provide Enhanced Open‐Circuit Hydrogen Evolution

Abstract

In this paper we prepare facetted “black” TiO2 nanotube arrays (NTAs) with a bamboo‐type structure which exhibits an enhanced performance for open‐circuit H2 generation without the use of any noble metal co‐catalyst. The TiO2 nanotubes were formed by applying alternating positive and negative voltages. During the electrochemical formation, not only a bamboo structure is formed but the tubes are reduced in the cathodic cycle. After a rapid annealing treatment of these tubes in air at 500 °C for 10 s, the bamboo rings (knots) provide (001) facets preferentially located at the knot, while (101) planes prevail on the smooth part of tube between knots, as shown by TEM. The short annealing time keeps Ti3+/oxygen vacancies (VO) as co‐catalytically active centers still preserved in the TiO2 NTAs. The results of intensity modulated photocurrent spectroscopy (IMPS) and open‐circuit potential decay measurements (VOC) indicate that these faceted and reduced TiO2 nanotube arrays provide an efficient separation and reaction of photo‐generated charge carriers, leading to an improved photocatalytic H2 evolution performance.

Rational Regulation of Surface Free Radicals on TiO2 Nanotube Arrays via Ag2O–AgBiO3 towards Enhanced Selective Photoelectrochemical Detection

“…A kind of advanced 1D morphology for high-efficient photoelectrochemical (PEC) reaction is the self-organized titanium dioxide nanotube arrays (TiO 2 NTAs) produced by electrochemical anodization on a Ti substrate [ 10 , 11 , 12 , 13 ]. Previous works have demonstrated the use of TiO 2 NTA-based photoanodes for organic pollutant degradation and renewable energy production [ 14 , 15 , 16 , 17 , 18 ], in which TiO 2 NTAs exhibit considerable performance due to their large surface area, high chemical and mechanical stability, oriented electron transport, and tunable morphologies [ 19 , 20 , 21 ]. Recently, inspired by the above-mentioned concept, detection sensors based on the PEC characteristic of TiO 2 NTAs for organics have been established [ 22 , 23 , 24 ] and are considered to be a potential method to replace and solve these issues in the traditional way.…”

One-step electrosynthesis of visible light responsive double-walled alloy titanium dioxide nanotube arrays for use in photocatalytic degradation of dibutyl phthalate

“…13 This length is quite comparable to the inner dimensions of TiO 2 nanotubes, which indicates that replacing the TiO 2 nanoparticles with a nano-tubular layer can particularly effective in reducing the frequency of unproductive recombination. 14 Over the past decade, various morphologies of TiO 2 nanotubes have been developed, such as bamboo-like 15 and Ybranched, 16 owed to their favorable properties, such as high surface area, enhanced mass transport and increased rate of diffusion. Comparing with traditional nanotubes, speciallyshape nanotubes have more adsorption and catalytic active sites, thus exhibiting higher catalytic performance and are gradually becoming the focus of research.…”