The key issue for TiO2 as an anode in lithium ion batteries (LIBs) is improving its electronic conductivity and ionic diffusion ability, which hinder its rate performance and practical application in LIBs. Herein, we design a novel strategy using incompletely oxidized TiC as a precursor to prepare carbon-doped TiO2 multiple-phase nanocomposites with improved ionic and electronic conductivity. The as-prepared carbon-doped TiO2 multiple-phase (TiO2(B) and anatase as major phases; TiC as a minor phase) nanocomposites exhibit a superior rate performance of up to 142 mA h g−1 at 15 000 mA g−1 (∼45 C) as well as excellent cycling stability as anode materials in lithium-ion batteries, showing great potential for application in lithium-ion batteries. Through a combination of carbon doping and the introduction of multiple-phases, not only is the electrochemical performance greatly enhanced in lithium ion batteries, but this carbon-doped TiO2 nanocomposite also shows high activity and stability for the electrochemical hydrogen evolution reaction from water.

To improve the electrochemical performance of TiO2 nanotube as anode materials in Li-ion batteries, N-doped TiO2 nanotube/N-doped graphene composites were prepared via hydrothermal synthesis followed by heat treatment in the presence of urea. The N-doped TiO2 nanotubes/N-doped graphene composites were characterized by X-ray powder diffraction, transition electron microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy. The electrochemical experiments demonstrated that the as-prepared sample exhibit superior discharge capacity (up to 369 mA h g−1 at 0.1 A g−1) as well as excellent rate ability (90 mA h g−1 even at 5 A g−1 at 180th cycle) as anode materials in lithium-ion batteries.

Here we report the electrochemical performance of N-doped ordered mesoporous carbon as an anode in sodium ion batteries for the first time. The experiments show that high reversible capacities as well as good rate performance can be achieved at room temperature; indicating a promising future for ordered mesoporous carbon in Na-ion batteries.

In photocatalytic solar water splitting systems, non-noble and highly active cocatalysts have always been pursued with tremendous interest. Herein an active and cheap photocatalyst, using Cu and graphene synergetically as co-catalysts immobilized on TiO2, was studied. This synergetic photocatalyst displayed enhanced photocatalytic hydrogen generation from water splitting in the presence of methanol as a sacrificial reagent. The hydrogen generation efficiency from the Cu–graphene synergetic cocatalyst was about 5 times higher than that of a pure graphene cocatalyst, and can be compared with that of systems containing the well-known Pt cocatalyst. Therefore this Cu–graphene synergetic cocatalyst provides an inexpensive means of harnessing solar energy to achieve efficient hydrogen evolution from water splitting.

Although many efforts have been done on the photocatalytic properties of anodic TiO2 nanotubes, much less work is done on the photocatalytic performance of TiO2 nanowires. Self-organized anodic TiO2 nanowire arrays have been fabricated using a simple electrochemical approach and used as photocatalysts in photodegradation of methylene blue (MB) dyes. Here we found for the first time TiO2 nanowires have better photocatalytic properties and incident photon-to-current efficiency (IPCE) than TiO2 nanotubes. N doped TiO2 nanowires showed further enhancement in photodegradation activity and photocurrent response in the visible region. Such TiO2 nanowires are expected to have great potential in photodegradation of pollutants, photovoltaic solar energy conversion and water splitting for hydrogen generation as well.Highlights► TiO2 nanowire arrays electrode fabricated via anodizing Ti foil. ► TiO2 nanowire arrays have higher photodegradation activity. ► N doped TiO2 nanowires enhanced visible-light photocatalytic activity.

Carboxylated-azobenzene chromophore modified TiO2 nanowire composites were prepared and characterized. Photocurrent measured with monochromatic incident light irradiation results showed that azobenzene modified TiO2 nanowire electrode had obviously higher photocurrent and broader visible light response covering range of 350–650 nm, and the wavelength position corresponding to the maximum photocurrent was red shift to about 470 nm. After alternate irradiation with UV and visible light, the azobenzene modified TiO2 nanowire electrode exhibited obvious photoelectrochemical switching properties. Furthermore, the photocurrent under visible light irradiation was much higher than that under UV irradiation due to the cis-to-trans isomerization transformation of azobenzene chromophore.

•A noble-metal-free photocatalytic system for highly efficient overall water splitting was developed.•The effective charge separation and transfer in SnOx–NiGa2O4 composites, the photocatalytic activity of the optimized composites photocatalysts can reach up to more than one order of magnitude greater than that of NiGa2O4 or SnOx alone respectively.•Under the visible irradiation the photocatalysts also displayed well both photocatalytic hydrogen evolution and pollution degradation potentials.•A deep understanding of the charge separation mechanism based on the band alignment in such system was provided.Overall water splitting is a huge challenge for the semiconductor photocatalysts. Herein, we investigated the high effective photocatalytic overall water stoichiometrically splitting into H2 and O2 activity using the SnOx–NiGa2O4 (SNG) composites photocatalysts. Because of the effective charge separation and transfer in SnOx–NiGa2O4 composites, the photocatalytic activity of the optimized composites photocatalysts can reach up to more than one order of magnitude greater than that of NiGa2O4 (NGO) or SnOx alone respectively. In addition, under visible light irradiation the photocatalysts also displayed well both photocatalytic hydrogen evolution and pollution degradation potentials. More importantly, we further elucidated the essential band gap relation between the SnOx and NiGa2O4 in the heterostructure, and a deep understanding of the charge separation mechanism based on the band alignment in such system was provided. Our study demonstrates great potential of the SnOx–NiGa2O4 composites to be an attractive photocatalysts for the overall water splitting or pollution degradation under visible light irradiation.The high effective photocatalytic overall water stoichiometrically splitting into H2 and O2 activity using the SnOx–NiGa2O4 composites photocatalysts was reported. Because of the effective charge separation and transfer in SnOx–NiGa2O4 composites, the photocatalytic activity of the optimized composites photocatalysts can reach up to more than one order of magnitude greater than that of NiGa2O4 or SnOx alone respectively. under visible light irradiation the photocatalysts also displayed wellboth photocatalytic hydrogen evolution and pollution degradation potentials. More importantly, we further elucidated the essential band gap relation between the SnOx and NiGa2O4 in the heterostructure, and a deep understanding of the charge separation mechanism based on the band alignment in such system was provided. Our study demonstrates great potential of the SnOx–NiGa2O4 composites to be an attractive photocatalysts for the overall water splitting or pollution degradation under visible light irradiation.Download high-res image (137KB)Download full-size image

To improve the electrochemical performance of TiO2 nanotube as anode materials in Li-ion batteries, N-doped TiO2 nanotube/N-doped graphene composites were prepared via hydrothermal synthesis followed by heat treatment in the presence of urea. The N-doped TiO2 nanotubes/N-doped graphene composites were characterized by X-ray powder diffraction, transition electron microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy. The electrochemical experiments demonstrated that the as-prepared sample exhibit superior discharge capacity (up to 369 mA h g−1 at 0.1 A g−1) as well as excellent rate ability (90 mA h g−1 even at 5 A g−1 at 180th cycle) as anode materials in lithium-ion batteries.

The key issue for TiO2 as an anode in lithium ion batteries (LIBs) is improving its electronic conductivity and ionic diffusion ability, which hinder its rate performance and practical application in LIBs. Herein, we design a novel strategy using incompletely oxidized TiC as a precursor to prepare carbon-doped TiO2 multiple-phase nanocomposites with improved ionic and electronic conductivity. The as-prepared carbon-doped TiO2 multiple-phase (TiO2(B) and anatase as major phases; TiC as a minor phase) nanocomposites exhibit a superior rate performance of up to 142 mA h g−1 at 15000 mA g−1 (∼45 C) as well as excellent cycling stability as anode materials in lithium-ion batteries, showing great potential for application in lithium-ion batteries. Through a combination of carbon doping and the introduction of multiple-phases, not only is the electrochemical performance greatly enhanced in lithium ion batteries, but this carbon-doped TiO2 nanocomposite also shows high activity and stability for the electrochemical hydrogen evolution reaction from water.

In photocatalytic solar water splitting systems, non-noble and highly active cocatalysts have always been pursued with tremendous interest. Herein an active and cheap photocatalyst, using Cu and graphene synergetically as co-catalysts immobilized on TiO2, was studied. This synergetic photocatalyst displayed enhanced photocatalytic hydrogen generation from water splitting in the presence of methanol as a sacrificial reagent. The hydrogen generation efficiency from the Cu–graphene synergetic cocatalyst was about 5 times higher than that of a pure graphene cocatalyst, and can be compared with that of systems containing the well-known Pt cocatalyst. Therefore this Cu–graphene synergetic cocatalyst provides an inexpensive means of harnessing solar energy to achieve efficient hydrogen evolution from water splitting.