CERAMICS INTERNATIONAL
·
2015
·
IF 2.605
Guanjun Wen,Kuibao Zhang,Haibin Zhang,Yuancheng Teng,Ye Zhou
Synroc is recognized as the second generation waste form for safety disposal of high-level radioactive waste (HLW). In this study, the Synroc mineral of rutile was employed as host phase for the immobilization of Nd 2 O 3 and CeO 2 , which were selected as surrogates of trivalent and tetravalent actinide nuclides. Rutile waste forms with different Nd 2 O 3 and CeO 2 incorporations were prepared under normal pressure sintering. Nd 2 Ti 2 O 7 pyrochlore was produced as the target phase in 1100 °C calcined Nd-bearing TiO 2 . Lattice stabilization of CeO 2 in rutile TiO 2 could not be accomplished even under 1500 °C sintering. The 28 day normalized leaching rates ( LR i ) of Ti and Nd in Nd-bearing rutile, which decline congruously as the Nd 2 O 3 content increases, are lower than 3×10 −5 g m −2 d −1 . The incorporation of CeO 2 significantly impairs the aqueous durability of rutile waste form.
研究领域:
核废料管理
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
·
2017
·
IF 3.454
Qilai Zhou,Yasuhisa Oya,Takumi Chikada,Wen Zhang,Lihong Xue,Youwei Yan
Ultrafine lithium titanate (Li 2 TiO 3 ) powder was synthesized by hydrothermal method . The phase formation and transition condition among α, β, and γ-Li 2 TiO 3 were discussed. XRD and ICP-AES showed the single α-phase was formed at 180 °C with 2 h hydrothermal reaction, and it transited into β-phase at 400 °C. SEM observation and EDS analysis confirmed the dissolution of TiO 2 and the formation of α-Li 2 TiO 3 proceeded simultaneously with preferable growth direction of (-133) lattice. During the phase transition, the powder maintained the small crystallite , which facilitated the fabrication of Li 2 TiO 3 bulk with small grain size. After the Ar + irradiation, the surface region to the depth of 3 μm of Li 2 TiO 3 ceramic was affected, where the decrease of crystallization and disturbance of short-range order were confirmed by GIXRD and Raman spectroscopy . In spite of the structure change at the surface area, the ceramic bulk maintained the same.
研究领域:
材料科学
·
核能工程
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2016
·Vol. 6
·期 20
·7604-7614
·
IF 5.287
Juan Yang,Xiaoxiao Shen,Jianping Wei,Lina Zhang,Dan Zhao,Banghua Yao
Nanostructured H-titanate materials with different morphologies, including nanotubes, nanosheets and nanofibers, are examined as active photocatalysts for the selective oxidation of alcohols to elucidate the relationship between the structure and the catalytic properties. H-titanate nanotubes (H-TNTs) exhibit superior photocatalytic performance under visible light irradiation to H-titanate nanosheets (H-TNS) and nanofibers (H-TNF) although they have similar crystal structures. N2 adsorption–desorption isotherms and low temperature electron spinning resonance (ESR) spectra indicate that H-TNTs possess a huge specific surface area and a large fraction of unsaturated surface Ti active sites. This facilitates the formation of a high concentration of surface complexes between unsaturated Ti atoms and adsorbed alcohols and consequently enhances the visible-light absorption, which play key roles in achieving high activity for ligand-to-metal charge transfer (LMCT) based photocatalytic systems. The unique structural features of 1D nanotubes promote the charge-transfer efficiency from the coordinated alcohol species to surface Ti atoms, which is evidenced by low temperature ESR under visible light and photoelectrochemical characterizations. Furthermore, pyridine-adsorbed Fourier transform infrared (FT-IR) spectra reveal that there are effective Brønsted acid sites on the surface of H-TNTs, which can accelerate the decomposition of Ti-peroxide species and the regeneration of Ti active sites. In brief, the features of 1D nanotubes, including large surface area, abundant unsaturated surface Ti sites, high concentration of surface complex, strong visible-light absorption, effective charge transfer and Brønsted acidity, contribute to the high photocatalytic activity of H-TNTs.
研究领域:
材料科学
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催化化学
·
纳米技术
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE ELECTROCHEMISTRY
·
2020
·Vol. 24
·期 4
·997-1006
·
IF 2.646
Song Haishen,Yuan Hailiang,Chen Hezhang,Tang Anping,Xu Guorong,Liu Lihua,Zhang Zhian,Kuang Qiujuan
The commercial application of lithium-sulfur (Li-S) battery is hampered by the insulating characteristic and dissolution problem of sulfur and lithium polysulfides. Herein, a mesoporous TiO 2 @PPy material has been fabricated to act as the chemical immobilizer for sulfur species in Li-S battery. In the structure, PPy layer is covered uniformly on surface of the mesoprous TiO 2 , forming a core-shell structure. The well-developed mesopores act as the reservoir for sulfur, while the PPy layer improves the conductivity of material and further prevents diffusion of soluble polysulfides. The synthesized TiO 2 /S@PPy composite delivers an improved rate capability and cycling stability, with an initial discharge specific capacity of 1013.7 mAh g −1 at 0.1 C. In addition, the composite reserves a high capacity of 567.0 mAh g −1 after 300 cycles at 0.5 C, with a decreasing rate of 0.103% per cycle.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2024
·
IF 3.5
Mengting Jiang,Xiaopeng Li,Tengfei Deng
In this study, aluminum titanate/anorthite (Al 2 TiO 5 -CaAl 2 Si 2 O 8 ) ceramics were fabricated from ferrotitanium slag through phase reconstruction. Stabilization of the ceramic was achieved by migration of Mg element into Al 2 TiO 5 phase. The results indicated that optimal performance was achieved with the addition of 4 wt% MgO and 60 wt% ferrotitanium slag at 1370°C. The ceramic exhibited bulk density of 3.11 ± 0.01 g/cm 3 , thermal storage density of 1.51 kJ/cm 3 , and thermal expansion coefficient of 3.40 × 10 −6 /°C (1000°C), respectively. Additionally, the solid solution of Mg 2+ in the Al 2 TiO 5 lattice reduced the formation of microcracks and enhanced the mass transfer process. Consequently, the sintering temperature decreased from 1415°C to 1370°C while the bending strength increased from 61.25 ± 1.05 MPa to 75.92 ± 7.72 MPa. Furthermore, finite element simulation demonstrated that higher thermal expansion led to concentrated thermal stress, potentially increasing the possibility of ceramic cracking. This research provides a new strategy for preparing low thermal expansion ceramics from titanium-containing solid waste.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Xiaoyun Dong,Huimin Hao,Ningning Wang,Hong Yuan,Xianjun Lang
Semiconductor photocatalysis can carry out selective chemical transformations under ambient conditions, mitigating the associated environmental consequences. However, a single semiconductor photocatalyst usually cannot perform the transformations satisfactorily from the aspects of light-absorption, efficiency, and selectivity , etc. To address these challenges, cadmium sulfide (CdS)/titanate hybrid was fabricated by simultaneously growing titanate and CdS and had been comprehensively characterized. The optimized CdS/titanate hybrid can power the highly selective oxidative homocoupling of amines under the irradiation of green light-emitting diodes (LEDs). Specifically, CdS with a narrow bandgap captures green light; the conduction band of titanate activates molecular oxygen (O 2 ). The valence band of CdS could ensure the selective oxidative homocoupling of amines in methanol (CH 3 OH). The hybridization between CdS and titanate accounts for the expeditious oxidative homocoupling of amines into imines and the improved stability. Reactive oxygen species (ROS) quenching experiments and in situ electron paramagnetic resonance (EPR) tests suggest that superoxide anion (O 2 − ) and benzylamine radical are intermediates en route to imines. This work highlights the viability of hybridization of dual semiconductor nanostructures in implementing visible light-powered selective conversions.
研究领域:
材料科学
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环境化学
·
半导体技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2020
·
IF 5.774
Jingtao Bi,Jingkang Wang,Xin Huang,Qingqing Tao,Miao Chen,Ting Wang,Hongxun Hao
As a superior cation-exchanger and photocatalyst, titanate exhibited efficient ability for heavy metals decontamination and organics degradation. However, no reports about simultaneous removal of heavy metals and organics by using titanate has been found. The influence of intercalated heavy metal on the photocatalytic performances of titanate and its mechanism was poorly understood. In this work, titanate materials with different amounts of intercalated Pb(II) were prepared. Analytical TEM mapping images showed the uniform distributions of intercalated Pb(II) in titanate, excluding the formation of segregated nano-domains comprising either titanate or Pb-titanate. The crystalline and luminescent properties, which are relevant with the specific surface area and migration/recombination of the charge carriers, were considered as critical factors influencing the photocatalytic performance since the surficial charge states and derived band structures of titanate with different amounts of Pb(II) were almost identical. Steady state reaction experiments revealed that the catalytic activity of titanate after Pb(II) intercalation first sharply increased for 0.10Pb-Titanate and then decreased with further Pb(II) insertion. Better catalytic performance of 0.10Pb-Titanate was attribute to larger specific surface area, superior sorption affinity, higher excited charge carrier’s quantity and satisfied luminescence lifetime. Finally, it was observed that simultaneous removal strategy by pure titanate not only enhanced the sorption of lead ions than individual removal system but also promoted the photocatalytic ability than 0.10Pb-Titanate, which provides a new idea for the utilization and optimization of titanate materials for simultaneous decontamination of heavy metals and organics.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Hongxia Liu,Hui Mei,Shiping Li,Longkai Pan,Zhipeng Jin,Gangqiang Zhu,Laifei Cheng,Litong Zhang
Bismuth titanate (Bi 12 TiO 20 ) with unique sillenite structure has been shown to be an excellent photocatalyst for environmental remediation. However, the narrow light-responsive range and rapid recombination of photoinduced electrons-holes limit the photocatalytic performance of Bi 12 TiO 20 . To overcome the limitations, a practical and feasible way is to fabricate heterojunctions by combining Bi 12 TiO 20 with suitable photocatalysts. Here, using a facile chemical precipitation method, a novel and hierarchical core–shell structure of n-Bi 12 TiO 20 @p-BiOI (BTO@BiOI) heterojunction was rationally designed and synthesized by loading BiOI nanosheets on BTO nanofibers. The constructed BTO@BiOI composites exhibited significant charge transfer ability due to the synergistic effects of the built-in electric field between BTO and BiOI as well as close interfacial contacts. In addition, the narrow bandgap characteristics of the BiOI led to wide light absorption ranges. Therefore, the BTO@BiOI heterojunction exhibited an improved photocatalytic performance under visible light irradiation. The NO removal efficiency of optimal BTO@BiOI was 45.7%, which was significantly higher compared to that of pure BTO (3.6%) or BiOI (23.1%). Moreover, the cycling experiment revealed that BTO@BiOI composite has a good stability and reusability. The possible mechanism of photocatalytic NO oxidation over BTO@BiOI was investigated in detail.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Guanzheng Wang,Wenjiang He,Zhentao Yuan,Lu Li,Xiao Wang,Wenshen Tang,Zhaolin Zhan
The slow diffusion rate of lithium ions limits commercial TiO 2 from being used at scale in LiBs. This paper presents the strategy used to synthesize a homojunction anatase/rutile-TiO 2 core-shell microsphere enriched with oxygen vacancies. Oxygen vacancies and interfacial shared storage accelerate electron mobility and improve lithium-ion diffusion kinetics. Electrochemical AC impedance measurements show that the Li + diffusion coefficient of A/R-TiO 2 -V o 2 samples with oxygen vacancies is (1.14 × 10 -12 cm 2 /s), which is higher than the diffusion coefficient of A/R-TiO 2 samples without oxygen vacancies (9.28 × 10 -14 cm 2 /s). The study of the effect of oxygen vacancy content on crystal structure and lithium-ion storage capabilities was quantitatively modulated. The specific capacity of an A/R-TiO 2 -V o 2 anode containing a moderate number of oxygen vacancies was 405 mAh/g after 450 cycles at 0.5 C, which is 121% of the theoretical maximum. This high-capacity behavior can be mainly attributed to the synergistic effect of core-shell hollow structures, interfacial shared storage, and oxygen vacancies generating additional active sites located at grain boundaries that are available for lithium storage. This strategy of oxygen defect engineering combined with heterojunctions can be extended to other materials with similar dilemmas.
研究领域:
材料科学
·
电化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Tianze Zhang,Rui Wang,Junpeng Xiao,Lu Li,Xinzhi Ma,Weiguang Zhang
Benefitting from the large interlayer spacing, ultrahigh conductivity and abundant surface chemistry, Ti 3 C 2 T x has been a promising electrode material for supercapacitors (SCs). CoS has attracted much attention due to its low cost, weak Co-S bond and relatively high theoretical capacity. Herein, CoS nanowires were grown on few-layered Ti 3 C 2 T x by one-step solvothermal method as a SC electrode. Within the composite, Ti 3 C 2 T x could function as conductive network and buffer matrix to provide ultra-fast electronic transport and relieve volume expansion of CoS nanowires. Simultaneously, the active CoS nanowires with high capacitance act as interlayer spacer to restrain the restacking of Ti 3 C 2 T x nanosheets . As a result, CoS/Ti 3 C 2 T x -5 electrode exhibits a remarkable improvement specific capacitance of 528 F g −1 at a current density of 1 A g −1 and ultrahigh capacitance retention of 99.3% after 20 000 cycles at a current density of 10 A g −1 . The attempts and efforts made in this work provide a prototype for achieving excellent electrochemical properties .
研究领域:
材料科学
·
能源存储
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2019
·
IF 4.175
Yanping Gao,Chao Wang,Pengfei Hu,Fengyi He,Minghong Wu,Haijiao Zhang
Hierarchical TiO 2 nanostructures have shown a good prospect for energy storage and conversion. However, the intrinsic low conductivity and sluggish reaction kinetics greatly hamper their applications as the anode materials for lithium-ion batteries (LIBs). Herein, an eco-friendly route has been developed as a scalable strategy for preparing the anatase TiO 2 nanostructures via a simple template-free hydrothermal process. The as-made TiO 2 product has a high surface area of 146.3 m 2 g −1 and a unique hierarchically branched nanostructure, which is constructed by the rigid trunk and flexible nanosheets . Significantly, the product demonstrates the uniform distribution of carbon/nitrogen in the TiO 2 architecture. Benefiting from these unique structural features, the TiO 2 -400 electrode shows a superior electrochemical performance for reversible lithium storage, demonstrating a high reversible capacity of 268.2 mA h g −1 at 100 mA g −1 after 600 cycles and long cycling life. This study also opens a new window for rational design of hierarchical nanostructures with excellent properties by an environmentally benign technique.
研究领域:
材料科学
·
能源存储
✓ 已验证
产品关联
DOI
高影响因子
Journal of Advanced Ceramics
·
2015
·Vol. 4
·期 2
·130-134
·
IF 0
Gao Yupeng,Wang Libo,Li Zhengyang,Zhang Yafei,Xing Baolin,Zhang Chuanxiang,Zhou Aiguo
Two-dimensional (2D) carbide Ti 3 C 2 was synthesized by exfoliating Ti 3 AlC 2 in HF solution and used for supercapacitive performance investigation in 3 M KOH electrolyte. The specific surface area (SSA) of as-synthesized Ti 3 C 2 was 22.35 m 2 /g. Ti 3 C 2 -based supercapacitor electrodes exhibited good energy storage ability and had a volumetric capacitance 119.8 F/cm 3 at the current density of 2.5 A/g. Moreover, the addition of carbon black into Ti 3 C 2 powders greatly improved the performance of Ti 3 C 2 -based capacitors because carbon black restrained the preferred orientation of 2D Ti 3 C 2 , providing fast ion transport channels, and in turn, decreasing electrical resistance from 16.7 Ω to 3.5 Ω.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
危险品化学品经营许可证（带存储）