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Nanostructured‐alloy‐type anodes have received great interest for high‐performance lithium‐ion batteries (LIBs). However, these anodes experience huge volume fluctuations during repeated lithiation/delithiation and are easily pulverized and subsequently form aggregates. Herein, an efficient method to stabilize alloy‐type anodes by creating defects on the surface of the metal oxide support is proposed. As a demonstration, PPy‐encapsulated SnS2 nanosheets supported on defect‐rich TiO2 nanotubes were produced and investigated as an anode material for LIBs. Both experimental results and theoretical calculations demonstrate that defect‐rich TiO2 provides more chemical adhesions to SnS2 and discharge products, compared to defect‐poor TiO2, and then effectively stabilizes the electrode structure. As a result, the composite exhibits an unprecedented cycle stability. This work paves the way to designing durable and active nanostructured‐alloy‐type anodes on oxide supports. [ABSTRACT FROM AUTHOR]

Abstract: The synthetic rutile and metal-doped LiFePO4 are prepared from the high-titanium residue and iron-rich lixivium, which are obtained from the ilmenite by a mechanical activation and leaching process. ICP results show that the rutile contains 92.01% TiO2, 1.59% Fe2O3, 0.034% MnO2 and 0.60% (MgO+CaO), which meet the requirement of the titanium dioxide chlorination process. The results also reveal that small amounts of Al3+, Ca2+ and Ti4+ precipitate in the FePO4·xH2O precursor. XRD and Rietveld-refine results show that the metal-doped LiFePO4 is single olivine-type phase and well crystallized, and Ti4+ occupy M1 site, Ca2+ occupy M2 site and Al3+ occupy both sites, which indicates the formation of cation-deficient solid solution. The sample exhibits a capacity of 123mAhg− 1 at 5C rate, and retains 94.3% of the capacity after 100cycles. [Copyright &y& Elsevier]

Abstract: The purpose of this study is to utilize the huge FeSO4·7H2O waste slag produced by the titanium dioxide industry. FeC2O4·2H2O precursors are synthesized at various pH values by using the waste slag and H2C2O4·2H2O as raw materials, and without any purifying process. ICP analysis confirms that the impurity content of FeC2O4·2H2O increases with the pH value. Crystalline cation-substituted LiFePO4 are prepared from the FeC2O4·2H2O precursors. The cation dopants do not obviously change the structure of LiFePO4, and all the samples are single olivine-type phase and well crystallized. The lattice parameters of LiFePO4 decrease with the increased dopants contents. The dopants limit the size of LiFePO4 nanocrystals, LiFePO4 particles agglomeration and, consequently, improve the electrochemical performance of LiFePO4. The cation-substituted LiFePO4 prepared from the waste slag show much better electrochemical properties than the pure LiFePO4 at high current rates. The optimal pH value for synthesizing FeC2O4·2H2O from the waste slag is about 1.0, with 96.6% iron recovery. The cation-substituted LiFePO4 prepared from this precursor exhibits the best electrochemical properties, which delivers a capacity of 152, 142 and 126mAhg−1 at 1C, 2C and 5C rate, respectively, and shows excellent cycling performance. [Copyright &y& Elsevier]

Abstract: Nanosized CdS coupled TiO2 nanocrystals were prepared by a microemulsion-mediated solvothermal method at relatively low temperatures. The prepared samples were characterized by X-ray photoelectron spectroscopy (XPS), BET surface area analysis, X-ray diffraction (XRD), UV–vis absorption spectroscopy (UV–vis), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM). It was found that the CdS coupled TiO2 materials consisted of uniform anatase TiO2 of 6–10nm with highly dispersed cubic phase CdS nanocrystals. The prepared samples exhibit strong visible light absorption at about 550nm. Meanwhile, they have high surface area in the range of 156–263m2 g−1 and mesoporous character with the average pore diameter of ca. 5.0–6.5nm. The coupling between the (101) crystal planes of anatase and (111) crystal planes of CdS was observed in the HRTEM image. Ti3+ signal was observed in the electron paramagnetic resonance (EPR) spectrum of CdS coupled TiO2 nanocrystals under visible light irradiation. It provided the evidence of an effective transfer of photo-generated electrons from the conduction band of CdS to that of TiO2. As expected, the nanosized CdS sensitized TiO2 nanocrystal materials showed enhanced activity in the oxidation of methylene blue in water or nitric oxide in air under visible light irradiation. The mechanism of photocatalysis on CdS coupled TiO2 nanocrystals under visible light is also discussed. [Copyright &y& Elsevier]

Nanocrystalline TiO2 (sample S1) was prepared from a titanium oxo cluster (Ti7O4(OEt)20) precursor via a sol–gel route. This photocatalyst showed a higher photocatalytic activity than the TiO2 (sample S2) obtained from titanium tetraisopropoxide. The samples were characterized by thermal analysis (TGA/DSC), X-ray diffraction, micro-Raman spectroscopy, transmission electron microscopy, N2 adsorption (BET surface area), infrared absorption spectroscopy (FT-IR) and X-ray photoelectron spectroscopy. The characterization results show that both samples are anatase nanocrystals with particle sizes of about 12 nm, but the more photocatalytically active sample S1 has more surface hydroxyl groups and larger surface area and pore volume than sample S2. [Copyright &y& Elsevier]

In view of the inferior specific capacity and low rate capability of titanium dioxide with individual-phase, multi-sized anatase/bronze nanoribbons with heterojunction structure are prepared by a hydrothermal ion exchange method in this study. The effects of calcination temperature on the crystallographic structure, architecture morphology and electrochemical properties of anatase/bronze nanoribbons are investigated. The results show that the prepared anatase/bronze nanoribbons present one-dimensional nanostrips structure with a bandwidth of about 100 nm, and nanofibers are attached to the surface. It is found that calcination temperature is critic in the crystallographic structure, architecture morphology and electrochemical performance of anatase/bronze nanoribbons. The multi-sized anatase/bronze nanoribbons prepared at 300 °C show improved electrochemical performance with superior specific capacity, outstanding rate capability and long cycle life. At the current density of 200 mA·g−1, the specific discharge capacity of the first circle reaches 728 mAh·g−1. Moreover, the specific discharge capacity remains 92.5 mAh·g−1 after 2000 charge-discharge cycles 2000 mA·g−1. The design of anatase/bronze heterojunction structure supplies a potential strategy to develop titanium-based anode with advantageous electrochemical performance. [Display omitted] • Multi-sized anatase/bronze nanoribbons with heterojunction was prepared. • Multi-sized architecture and heterojunction promote sodium storage. • As-obtained anatase/bronze nanoribbons showed good electrochemical performance. [ABSTRACT FROM AUTHOR]

Searching for affordable and efficient anode materials is of great significance for the development of sodium-ions batteries. Anatase-based electrode material has demonstrated reasonably voltage and outstanding cyclability. However, low specific capacity and poor Na+ transmission efficiency of conventionally prepared anatase material restrain its practical application. To achieve anatase-based electrode material with superior sodium storage, pompon-villus shaped hydrogen titanate/anatase composite with heterostructure is synthesized by a facile method. Thanks to the cooperative effect of unique pompon-villus architecture, open channel of hydrogen titanate, and specific heterostructure, the synthesized composite displays excellent rate performance and long cycle performance: the discharge specific capacity is remains 157.8 mAh·g−1 after 200 cycles at 0.1 A·g−1, and the discharge specific capacity is maintaining 104.1 mAh·g−1 after 1000 cycles at 2 A·g−1. This work supplies new fundamental strategy and paves an encouraging avenue in designing anatase-based electrode with improved electrochemical performance for sodium-ions batteries. [Display omitted] • Pompon-villus shaped hydrogen titanate/anatase was prepared for the first time. • Heterostructure was constructed between hydrogen titanate and anatase. • As-obtained hydrogen titanate/anatase showed good electrochemical performances. [ABSTRACT FROM AUTHOR]

Ultrathin TiO 2 nanosheets (NST) containing Ti3+ sites are developed as a photocatalyst that exhibits high degradation efficiencies (98.6%) for the degradation of enrofloxacin (ENR) under visible light. The increment of degradation efficiencies for ENR over NST is mainly due to the increase of Ti3+ and oxygen vacancies (OVs). Ti3+ sites on the surface of NST can be associated with ENR molecules through the formation of surface coordination species -COO∙∙∙Ti- intermediates, resulting in the activation of ENR. OVs on NST can adsorb and activate more O 2 molecules to accelerate the generation of O 2 - by photogenerated electrons reduction. The photogenerated holes quickly transfer to the surface of the catalyst to directly degrade the activated ENR. Finally, a possible mechanism about the synergistic effect of coordination activation and photocatalysis is proposed over NST at a molecule level. This study highlights the significant role of coordination activation in the photocatalytic degradation of antibiotics. [Display omitted] • TiO 2 nanosheets with Ti3+ sites and oxygen vacancies are synthesized for the efficient degradation of enrofloxacin (ENR). • ENR molecules are activated on the catalysts via surface -COO∙∙∙Ti- coordination species. • O 2 molecules can be adsorbed and activated on oxygen vacancies to generate O 2 - by photo-generated electron reduction. • A synergistic mechanism of coordination activation and photocatalysis is proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Surface phosphorylated TiO 2 nanofibers with binary-phase are fabricated successfully. • The reactivity of TiO 2 nanofibers is boosted by surface phosphorylation treatment. • The synthesized SP-TiO 2 -A/B shows significantly improved electrochemical performance. TiO 2 -based nanostructure has been reported as one of the most developable anode materials for sodium-ion batteries, but its low capacity and poor rate capability bring an unavoidable challenge and impede the practical application. In this study, surface phosphorylated TiO 2 nanofibers with anatase/bronze binary-phase are fabricated using ion exchange-annealing treatment and subsequent phosphorylation. The resulting nanofibers can serve as an efficient electrode material for sodium storage, affording a reversible capacity of 224.7 mAh g−1 at 200 mA g−1 and a superior high-rate cycling capability of 108.9 mAh g−1 at 2000 mA g−1 after 1000 cycles. XPS and HRTEM reveal that the synthesized SP-TiO 2 -A/B nanofibers present heterojunction-boundary between anatase/bronze binary-phase and well-crystallized internal-structure with disordered/amorphous surface, and a high ratio of active surface was motivated through phosphorylation and Na+ ion storage behavior was efficiently modulated. The surface phosphorylation engineering provides a promising strategy to develop Na-storage electrodes with superior electrochemical performance. [ABSTRACT FROM AUTHOR]

CdS/TiO2heterojunction nanofibers have been successfullysynthesized through the photodeposition of CdS on 1D TiO2nanofibers that were prepared via a facile electrospinning method.The as-synthesized samples showed high photocatalytic activities uponselectively oxidizing a series of alcohols into corresponding aldehydesunder visible light irradiation. TEM observations revealed that CdSwas closely grown on the TiO2nanofibers. Moreover, itwas found that the CdS/TiO2nanofibers that were photodepositedfor 4 h exhibited the highest catalytic activity, with a conversionof 22% and a selectivity of 99%, which were much higher than thoseof commercial CdS. In addition, we also discuss the photoabsorptionperformance and the reaction mechanism of the photocatalytic oxidationof alcohols. [ABSTRACT FROM AUTHOR]

The nano-TiO 2 samples with different morphologies were prepared for visible-light-driven photocatalytic selective oxidation of benzylamine and the role of active sites between morphologies and photocatalytic performances was discussed. [Display omitted] • Three types of anatase nano-TiO 2 with different morphologies were prepared for visible-light-driven photocatalytic selective oxidation of benzylamine. • The surface properties of the samples were systematically studied by various characterization techniques. • Coordinatively unsaturated Ti atoms can chemisorb and activate benzylamine molecules via forming H-N ... Ti coordination species. • Oxygen vacancies can chemisorb and activate oxygen molecules to form reactive oxygen species. • The role of active sites between morphologies and photocatalytic performances was discussed. Enormous efforts have been devoted to exploring the influence of the materials' morphology on photocatalytic performance, while the role of active site between them attracts less attention. Herein, three types of anatase nano-TiO 2 with different morphologies were successfully prepared for visible-light-driven photocatalytic selective oxidation of benzylamine. The material properties of the samples were systematically studied by various characterization techniques such as XRD, SEM, TEM, AFM, XPS, UV–vis DRS, ESR and in situ FTIR. Due to possessing clear advantages especially for having more active sites (coordinatively unsaturated Ti atoms and oxygen vacancies), the TiO 2 with porous structure shows more excellent photocatalytic performance than the other samples. Coordinatively unsaturated Ti atoms can chemisorb and activate benzylamine molecules via forming H-N ... Ti coordination species, whose absorption property of visible light guarantees that TiO 2 samples can achieve the photocatalytic process under visible light. Oxygen vacancies can chemisorb and activate oxygen molecules to form reactive oxygen species (superoxide radical) by the reduction of photogenerated electrons. Finally, a possible synergetic mechanism based on the interaction of reactants and catalyst interfaces was proposed at the molecular level to illustrate the photocatalytic process. [ABSTRACT FROM AUTHOR]

Cu 2 O clusters/TiO 2 nanosheet (CNSX) as a photocatalyst is created to tailor the selectivity of CO 2 photoreduction. The catalysts show different selectivity of CO and CH 4 with the increase of Cu 2 O mass. TiO 2 nanosheet (NS) exhibits 100% selectivity of CH 4 with a rate of 37.6 μmol g−1 h−1. However, CO 2 would be converted to CO with selectivity of 98% and yield of 162.6 μmol g−1 h−1 on 5 wt% Cu 2 O/TiO 2 nanosheet (CNS3). The Ti···CO 2 –···Ti coordination intermediate on Ti3+ sites is responsible for CH 4 formation, whereas the Cu···CO 2 ···Ti specie on Cu1-δ and Ti4+δ sites determines CO production. The Cu+–Ti3+ interface interaction on CNSX surface can generate Cu1-δ and Ti4+δ sites and eliminate Ti3+ via the charge transfer from Ti3+ to Cu+. The selectivity is thus tailored effectively by Cu+–Ti3+ interface interaction mediated CO 2 coordination model. This work would offer a new perspective for tailoring the selectivity of CO 2 photoreduction. The selectivity of CO and CH 4 from CO 2 photoreduction is effectively tailored by Cu+–Ti3+ interface interaction mediated CO 2 coordination model over Cu 2 O clusters/TiO 2 nanosheet. [Display omitted] • Cu 2 O clusters/TiO 2 nanosheets (CNSX) are constructed as a photocatalyst for selective conversion of CO 2. • The catalysts show different selectivity of CO and CH 4 with increasing Cu 2 O mass. • The Cu+–Ti3+ interface interaction on CNSX surface could generate Cu1-δ and Ti4+δ sites and eliminate Ti3+. • The Ti···CO 2 –···Ti coordination intermediate would be generated on Ti3+ sites, which is responsible for CH 4 formation. • Cu1-δ and Ti4+δ sites cause the formation of Cu···CO 2 ···Ti specie for determining CO production. [ABSTRACT FROM AUTHOR]

Abstract: Ca2Nb2O7 (CN) nanopolyhedra with relatively high surface area and small crystallites have been prepared by a microwave-assisted template-free hydrothermal method for the first time. The samples are characterized by powder X-ray diffraction (XRD), UV–vis diffuse reflectance spectra (UV–vis DRS), N2-adsorption, and Transmission electron microscopy (TEM). A comparative study on the photocatalytic degradations of methyl orange (MO) in aqueous solution and benzene in gas phase has been carried out between Ca2Nb2O7 nanopolyhedra and TiO2. Results show that the MO and benzene could be effectively degraded and mineralized over the CN samples. Due to the higher photoabsorption performance and concentration of ls, TiO2 exhibit a superior photocatalytic activity for the degradation of MO compared with the CN samples. However, the weaker redox ability of the photogenerated hole–electron pairs induces the lower mineralization ratio of MO. Fourier transform infrared (FT-IR) analysis reveals that the photocatalytic active sites of TiO2 have been blocked by stable intermediates, leading to the deactivation of the photocatalyst. In contrast, although the CN samples exhibit a lower photocatalytic degradation rate of MO, they show a much higher mineralization ratio of MO and benzene compared with TiO2. Therefore, the CN samples maintain a clean surface during the photocatalytic process, resulting in a high and stable photocatalytic degradation performance. In addition, water plays a key role in the photocatalytic degradation of organic pollutants. [Copyright &y& Elsevier]

Abstract: We demonstrate a simple, improved and novel approach for the synthesis of a kind of anatase TiO2 nanosheets and Li4Ti5O12 anode material with excellent electrochemical performance from the natural ilmenite. We use the H2O2 to leach the Ti from the hydrolyzed titania residue under alkaline condition of leaching. Before boiling, the LiOH was added into the leach solution. The obtained precipitation of titanium dioxide hydrate can be purified and refined into special nanostructure by the addition of LiOH. SEM and XRD show that the as-prepared TiO2 are special nanostructure and well-crystallized anatase phase. The analysis of elemental contents reveals that the content percent of TiO2 in as-prepared TiO2 nanosheets is more than 99%. Moreover, the titanium dioxide hydrate can be used to prepare Li4Ti5O12 anode material directly. The obtained Li4Ti5O12 shows charge specific capacities of 161,138 and 113mAhg−1 at 0.1C, 0.5C and 1C rates, respectively, and excellent cycling stability. [Copyright &y& Elsevier]

Abstract: We demonstrate a simple, rapid, inexpensive and novel approach for the synthesis of a kind of anatase TiO2 nanowires. The method is based on a hydrothermal method under normal atmosphere without using the complex Teflon-lined autoclave, high concentrations NaOH solution and long reaction time. The as-prepared materials are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical measurements. The obtained anatase TiO2 nanowires show excellent performance. The initial Li insertion/extraction capacity is 260 and 224mAhg−1 at 20mAg−1, respectively. In the 20th cycle, the reversible capacity still remains about 216mAhg−1, exhibiting excellent cycling stability. The discharging capacity is about 159mAhg−1 in the 20th cycle at 200mAg−1, demonstrating a good high-rate performance. Anatase TiO2 nanowires might be a promising anode material for lithium-ion batteries. [Copyright &y& Elsevier]

Abstract: We demonstrate a simple and novel approach for the synthesis of a kind of anatase TiO2 nanowires. The method is based on a hydrothermal method under normal atmosphere without using the complex Teflon-lined autoclave, high concentrations NaOH solution and long react time. The as-prepared materials are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and electrochemical measurements. The obtained anatase TiO2 nanowires show excellent performance. There is a potential plateau at 1.77 and 1.88V in the process of Li insertion and extraction, and the initial Li insertion/extraction capacities are 283 and 236mAhg−1 at the density of 20mAg−1, respectively. In the 20th cycle, the reversible capacities still remain about 216 and 159mAhg−1 at the current densities of 20 and 200mAg−1, respectively, and the coulombic efficiency is more than 98%, exhibiting excellent electrochemical performance. [Copyright &y& Elsevier]

Abstract: The hydrolyzed titania residue with mainly precipitated hydrated TiO2 is prepared from mechanically activated Panzhihua ilmenite leached by hydrochloric acid. We use H2O2 as a coordination agent to leach Ti from the hydrolyzed titania residue. The effects of H2O2 to-hydrolyzed titania residue mass ratio, leaching pH value, leaching temperature, leaching time, and H2O2 concentration on leaching of hydrolyzed titania residue by H2O2 are investigated. The recovery of Ti is above 98% under the optimal conditions. XRD shows that the peroxo-titania powder prepared by boiling the aqueous titanium peroxide solution is crystalline anatase phase. A well-crystallized anatase TiO2 and rutile TiO2 can be obtained through calcining at the temperature of 800 and 1000°C, respectively. EDS shows that the impurities including silicon are enriched in the leaching slag. Little Si is detected as the only impurity in the synthetic TiO2 due to the weak alkaline condition of leaching. [Copyright &y& Elsevier]

Abstract: The present work reports the renewable hydrogen production by an anaerobic photocatalytic reforming of glucose, a compound that could be derived from biomass, over noble-metal-loaded TiO2 photocatalyst. The effects of reaction parameters, such as reaction atmosphere, noble-metal loading, amount of loaded platinum, crystalline phase of TiO2, initial concentration of glucose, and the pH value of the reaction solution on the hydrogen evolution are systematically investigated. The results show that the photocatalytic H2 production from the glucose solution can be significantly enhanced by depositing various noble metals on anatase TiO2, and the hydrogen evolution rates are decreased in the order Pd>Pt>Au≈Rh>Ag≈Ru. For Pt/TiO2 the greatest photocatalytic reforming activity of glucose occurs as the Pt loading content of ca. 1.0wt.%. The presence of O2 and acid strongly inhibits the hydrogen production. The effect of initial concentration of glucose on the hydrogen evolution rate could be well represented by the Langmuir–Hinshelwood kinetics model. A probable mechanism for the photocatalytic reforming process was proposed and discussed. [Copyright &y& Elsevier]

Abstract: Titanate/anatase nanocomposites consisting of titanate nanotubes and leaf-like anatase TiO2 nanoparticles were successfully prepared via a novel combinational hydrothermal method. The samples were characterized by means of X-ray diffraction (XRD) and transmission electron microscopy (TEM). The activity of the nanocomposites was examined by photocatalytic decolorization of rhodamine B under visible light irradiation. It is found that the nanocomposites exhibited a much improved photocatalytic activity in comparison with titanate nanotube, anatase TiO2 nanoparticle, and even the commercial Degussa P-25. The photocatalytic mechanism of the as-prepared nanocomposites was discussed. [Copyright &y& Elsevier]

Abstract: Nanocrystalline titanium dioxide (TiO2) was prepared by sol–gel method and studied at eight different thermal treatment temperatures ranging from 373 to 1073K. The resulting material was characterized by transient surface photoconductivity, XRD, photoluminescence, liquid-phase photocatalytic activity and other characters. The photocatalytic activity of these catalysts was estimated by measuring the decomposition rate of Rhodamine B. The quantum yield of tion during TiO2 photocatalytic process was estimated in aqueous solution using terephthalic acid as a fluorescent probe. Analysis of the photoconductive spectrum of samples has revealed the existence of carriers with two different lifetimes (τ 1 and τ 2), which varied with the sample thermal treatment temperature in the same peculiar fashion. Both of the photoconductive carrier lifetime τ 1, τ 2 of titanium dioxide and liquid-phase photocatalytic activity were top at temperature 673K, and bottom at temperature 473K. The resistance of the samples was also found to be maximal at thermally treatment temperature 673K.The high photoactivity of titanium dioxide at temperature 673K can be explained by interfacial charge-transference between anatase and rutile, which can promote the separation of electrons and holes, finally leading to long carrier lifetime and large resistance. The study of relationship between them shows carrier lifetimes may be used as a new way to measure the photoactivity of different photocatalysts. [Copyright &y& Elsevier]

Ultrathin TiO 2 nanosheet with abundant Ti3+ is constructed as a photocatalyst for CO 2 conversion in the absence of any sacrificial reagents. The exposed Ti3+ as a Lewis base site may activate CO 2 to form bridging Ti···CO 2 −···Ti, resulting highly CH 4 yield via the synergistic effect of coordination-activation and photocatalysis. • Ultrathin TiO 2 nanosheets (NST) with abundant Ti3+ sites are constructed as a photocatalyst for conversion CO 2. • The catalyst (NST) exhibits a high yield (147.2 μmol g−1 h−1) and selectivity (96.8 %) for CH 4. • CO 2 would be selectively activated on the surface of NST via forming the bridging Ti···CO 2 −···Ti coordination species. • The synergistic effect about coordination-activation and photocatalysis can greatly enhance CH 4 yield efficiency. Ultrathin TiO 2 nanosheet (NST) with abundant Ti3+ sites is developed as a photocatalyst which exhibits a high yield (147.2 μmol g−1 h−1) and selectivity (96.8%) for CO 2 to CH 4. The results of in situ FTIR, in situ EPR and density functional theory (DFT) calculation suggest that CO 2 would be selectively activated on NST surface via forming the bridging Ti···CO 2 −···Ti coordination species which not only lowers the activation energy barrier, but also determines the selectivity of CH 4. Additionally, NST with the better separation and transfer ability for photogenerated electrons-holes can fleetly supply the electrons to CO 2 molecules for high efficiently producing CH 4 via the Ti-C coordination bond. Finally, a possible mechanism of the synergistic effect about coordination-activation and photocatalysis is discussed at a molecule level. This work would offer a perspective for designing an effective photocatalyst and tailoring the selectivity of products by coordination activation. [ABSTRACT FROM AUTHOR]