N-doped titanate nanostructures on gradient surface layer of one dimensional nanofibers synthesized on Ti electrode by chemical and thermal treatments
N-doped titanate nanostructures on gradient surface layer of one dimensional nanofibers synthesized on Ti electrode by chemical and thermal treatments
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通过化学和热处理在钛电极上合成的一维纳米纤维梯度表面层的氮掺杂钛酸盐纳米结构
DOI：
10.1039/c3ta13728g
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
Yoshinori Naruta and Hiroaki Takadama
中科院分区：
文献类型：
--
作者：
Rohit Khanna;Seiji Yamaguchi;Alireza Valanezhad;Tadashi Kokubo;Tomiharu Matsushita;Yoshinori Naruta and Hiroaki Takadama
TiO 2纳米结构由于其半导电性和光催化性能而引起了人们的广泛关注，但很少用作需要高导电性的水电解的功能电极。与TiO 2相比，由于钛酸盐的层状结构，预期N在钛酸盐中的高掺杂水平，这试图改善导电性。在这里，与通常使用的严重水热处理相比，通过温和的NaOH和HCl处理在Ti金属表面上合成具有高表面积和差结晶度的一维钛酸氢（H-titanate）纳米纤维的表面层。层状H-钛酸盐的不良结晶结构允许通过在700 °C或更高温度下的热处理将大量的N结合到其表面层中，从而将其转化为具有高电导率的Ti-氮氧化物，同时保持处理层的高表面积。深度剖面分析的化学和热处理的钛金属显示，O和H的浓度是最高的表面层的顶面。随着深度的增加，O和H的浓度逐渐降低，而N的浓度逐渐增加，表明处理后的纳米纤维表面层的结构梯度。纳米纤维表面层下方的致密区域由Ti 2N组成，其量随着温度的升高而增加。通过我们独特的化学和热处理在Ti电极表面上合成了这种没有明确界面的N掺杂钛酸盐纳米纤维的梯度表面层，并以不同的深度进行建模。本工作的具体目标是表征和研究在处理的钛电极上合成的H-钛酸盐纳米纤维的一维梯度表面层中的N-掺杂结构的形成机制。在钛电极上处理的一维纳米纤维表面层可以潜在地用于在其表面上固定分子催化剂之后的水的电分解。
TiO2 nanostructures have attracted much attention due to their semi-conductivity and photocatalytic properties, but are rarely used as functional electrodes for water electrolysis that requires high electrical conductivity. Compared to TiO2, a high doping level of N into titanates is expected due to their layered structure, which was attempted to improve the conductivity. Here, a surface layer of one dimensional hydrogen titanate (H-titanate) nanofibers with high surface area and poor crystallinity was synthesized on the surface of Ti metal by mild NaOH and HCl treatments, as compared to the commonly used severe hydrothermal treatments. The poorly crystallized structure of the layered H-titanate allowed the incorporation of a large amount of N into its surface layer by thermal treatments at 700 °C or more, thereby transforming it into Ti-oxynitrides with high electrical conductivity while retaining the high surface area of the treated layer. The depth profile analyses of the chemically and thermally treated Ti metal revealed that the concentration of O and H was the highest at the top surface of the surface layer. With increasing depth, the concentration of O and H decreased gradually whereas the concentration of N increased gradually, indicating gradients in the structures of the treated nanofibrous surface layer. The dense region below the nanofibrous surface layer was composed of Ti2N, whose amount increased with increasing temperature. This kind of gradient surface layer of N-doped titanate nanofibers without well-defined interfaces was synthesized on the surface of the Ti electrode by our unique chemical and thermal treatments and was modeled with varying depths. The specific objective of the present work is to characterize and study the mechanism of formation of the N-doped structures in a one dimensional gradient surface layer of H-titanate nanofibers synthesized on the treated Ti electrode. The treated one dimensional nanofibrous surface layer on a Ti electrode can be potentially used for the electro-splitting of water after fixation of molecular catalysts on its surface.
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DOI：
10.1016/j.jphotochem.2007.05.011
发表时间：
2007-12
影响因子：
4.3
作者：
T. Tran;A. Nosaka;Y. Nosaka
通讯作者：
T. Tran;A. Nosaka;Y. Nosaka
影响因子：
3.9
作者：
Wen, Puhong;Itoh, Hiroshi;Feng, Qi
通讯作者：
Feng, Qi
DOI：
10.3891/acta.chem.scand.16-1255
发表时间：
1962-01-01
期刊：
ACTA CHEMICA SCANDINAVICA
影响因子：
--
作者：
HOLMBERG, B
通讯作者：
HOLMBERG, B
多晶Ti-N薄膜电阻率负温度系数的起源
DOI：
10.1063/1.332044
发表时间：
1983
期刊：
影响因子：
--
作者：
Y. Igasaki;H. Mitsuhashi
通讯作者：
H. Mitsuhashi
影响因子：
1.1
作者：
Kawai, Takahiro;Kizuki, Takashi;Kokubo, Tadashi
通讯作者：
Kokubo, Tadashi