Nanomaterials
·
2022
·Vol. 12
·期 3
·542
·
IF 5.719
Liqin Yang,Zhihong Chen,Xin Wang,Mingliang Jin
The practical application of photocatalytic H2-evolution is greatly limited by its sluggish charge separation, insufficient active sites, and stability of photocatalysts. Zero-dimensional (0D) Ti3C2MXene quantum dots (MQDs) and amorphous Ti(IV) have been proven to be potential substitutes for noble co-catalyst to accelerate the separation of photogenerated electron-hole pairs and prevent the self-oxidation of photocatalysts, leading to better photocatalytic H2-evolution performance with long-term stability. In this study, amorphous Ti(IV) and MQDs co-catalysts were successfully deposited on ZnIn2S4(ZIS) microspheres composed of ultra-thin nanosheets via a simple impregnation and self-assembly method (denoted as MQDs/ZIS/Ti(IV)). As expected, the optimal MQDs/ZIS/Ti(IV) sample exhibited a photocatalytic H2-evolution rate of 7.52 mmol·g−1·h−1and excellent photostability without metallic Pt as the co-catalyst in the presence of Na2S/Na2SO3as hole scavenger, about 16, 4.02 and 4.25 times higher than those of ZIS, ZIS/Ti(IV), and MQDs/ZIS, respectively. The significantly enhanced photocatalytic H2-evolution activity is attributed to the synergistic effect of the three-dimensional (3D) flower-like microsphere structure, the amorphous Ti(IV) hole co-catalyst, and a Schottky junction formed at the ZIS–MQDs interface, which offers more active sites, suppresses self-photocorrosion, and photo-generates the charge recombination of ZIS.
研究领域:
材料科学
·
能源化学
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DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2025
·
IF 6.9
Di Wang,Jing Wang,Yiqiang Wu,Delin Sun,Wenlei Wang
Transition metal ions and non-metal co-doped carbon-based materials have attracted extensive attention due to their unique properties and excellent catalytic effect. Fe 2 O 3 /TiO 2 @Fe/Ti-N-C multifunctional photocatalyst with Fe-Ti alloy and abundant nitrogen defects was reported. The photocatalytic results showed that the removal rates of Cr (VI), Congo red (CR) and levofloxacin (LFX) in water by Fe 2 O 3 /TiO 2 @Fe/Ti-N-C were 88.46, 96.71 and 99.06 %, respectively. The photoelectric test results show that bimetallic conjugated structure of Fe and Ti can effectively increase the light absorption range and accelerate the carrier separation. N-defects can significantly increase the lifetime and concentration of photogenerated holes, thereby improving the catalytic efficiency of the photocatalyst. The single factor experiments proved that the optimal pH for the degradation of Cr(VI), CR and LFX by Fe 2 O 3 /TiO 2 @Fe/Ti-N-C was 1, 11 and 9, respectively. In addition, Ca 2+ and Mg 2+ promoted the degradation of Cr(VI) and inhibited the degradation of CR and LFX. SO 4 2- inhibited the degradation of Cr(VI) and promoted the degradation of CR and LFX. Cl - inhibited the degradation of Cr(VI), CR and LFX. This study elucidates the mechanism of N-defects and bimetallic sites in photocatalytic reactions, and provides theoretical support for efficient removal of heavy metals and organic pollutants in water.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
高影响因子
Materials Research Letters
·
2024
·
IF 8.6
Xiaoqi Mao,Lianwen Wang,Guodong Sun,Xuezhe Zhang,Yongqing Fu,Longlong Dong
Breaking trade-off barriers of strength-ductility in Ti alloys and their composites has been a key challenge for their engineering applications. Herein, we developed a new strategy of introducing β-Ti ductile zones in heterostructured (Cu@CNTs/TC4)+TC18 composites, which were synthesized using two-stepped ball milling, spark plasma sintering and hot rolling processes. Such composites are composed of TC18-coarse grain zones (CGZ) and (TiC+α'')-reinforced TC4-fine grain zones (FGZ). They achieve an exceptional high strength and high ductility, which are superior to those of TC4 alloys and homogeneous Cu@CNTs/TC4 composites. Heterogeneous interfacial microstructures of TC4-FGZ/TC18-CGZ play an important role in strengthening and toughening effects. The grain-coordinated deformation between TC18-CG and TC4-FG is also the key reason for achieving an exceptional ductility.
研究领域:
材料科学
·
力学工程
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产品关联
DOI
高影响因子
POLYHEDRON
·
2020
·
IF 2.343
Zhongmin Liu,Cong Wang,Yongchuan Wu,Longlong Geng,Xiuling Zhang,Dashuai Zhang,Hui Hu,Yongzheng Zhang,Xin Li,Wei Liu,Ping Na
The adsorption behavior of arsenic on adsorbent have been researched widely, but chemical adsorption of arsenic is uncommon. In this work, a kind of microporous metal-organic framework (MIL-125(Ti)) with columnar morphology and uniform size was solvothermally synthesized, and its chemical adsorption behavior and mechanism of arsenic were firstly investigated by experimental and simulation study. Remarkably, ultra-fast adsorption behavior and excellent arsenic removal capability was achieved. It takes only 20 min to rapidly remove 5 mg L −1 arsenic with 0.2 g L −1 MIL-125(Ti), which is far superior to the previously reported materials. Both experimental and simulation study results show that the adsorption of arsenic obeys a new chemical adsorption mechanism. Both As(III) and As(V) can easily replace the terephthalic acid ligand via competitive coordination and bind to the Ti active site of MIL-125(Ti). In addition, the reaction energy barriers for ligand substitution by H 2 O, As(III) and As(V) are 0.46, 0.33 and 0.15 eV, respectively, which further confirming that structure reforming of MIL-125(Ti) plays a key role for chemical adsorption. The study solves the difficulty of removing low concentration of arsenic and provides molecular-level understanding of the chemical adsorption mechanism of arsenic on MIL-125(Ti).
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
SEPARATION AND PURIFICATION TECHNOLOGY
·
2021
·
IF 7.312
Guanglai Mo,Linxi Wang,Jianhong Luo
It is a challenge to achieve efficient photocatalytic activity of pure MOFs. Herein, the defective NH 2 -MIL-125(Ti) with adjustable linker vacancy level was successfully created by thermal treatment. The band gaps of samples decreased and the more Ti-O clusters on the surface of the samples can be achieved as the time of thermal treatment increased from 0 to 500 min, both of which facilitated the photocatalytic activity for the reduction of Cr(VI). Moreover, the ligands from the surface to the inside of the samples were successively decarboxylated, resulting in the declined specific surface area and the increased proportion of mesoporous and the defect level. The moderate defect level in NH 2 -MIL-125(Ti) can be obtained as the time of thermal treatment was 300 min, which facilitated the separation of photogenerated charges, contributing to the highest photocatalytic activity for reduction of Cr(VI), which was 9.2 times than that of the initial MOFs. However, the excessive linker vacancy defect level in NH 2 -MIL-125(Ti) may result in the seriously affected crystal structure and the retarded separation of photogenerated charges.
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
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2025
·
IF 8.3
Jun-Qing Ye,Bin Cheng,Yunfei Bu,Jun-Feng Qian,Qian Liang,Ming-Yang He,Qun Chen
The development of high-efficiency photocatalysts for water splitting to hydrogen (H 2 ) is crucial for alleviating energy crisis and environmental problems. In this study, a novel type-II ternary heterojunction photocatalyst, CDs/NH 2 -MIL-125 (Ti)/Cu 2 O, was fabricated through the integration of NH 2 -MIL-125 (Ti) with Cu 2 O and carbon dots (CDs), exhibited excellent photocatalytic H 2 production rate of 12817.1 μmol/g/h with apparent quantum efficiency (AQE) of 17.13 % under visible light irradiation. Characterization revealed a uniform and dense structural integration with a high Brunauer-Emmett-Teller (BET) surface area of 275.9 m 2 g −1 and a suitable energy band gap of 2.18 eV. Furthermore, the heterostructures promoted efficient photo-generated carrier separation and enhanced reduction capabilities . Notably, CDs, serving as cocatalysts or electron acceptors, improved visible light utilization and electron migration, significantly boosting H 2 production. Insights from electron spin resonance (ESR) and density functional theory (DFT) calculations supported the migration mechanisms of electrons. This work presents a significant advance in photocatalytic technology for sustainable energy by designing high-performance CDs-modified heterojunction photocatalysts.
研究领域:
材料科学
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能源科学
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产品关联
DOI
高影响因子
DALTON TRANSACTIONS
·
2023
·Vol. 52
·期 11
·3517-3525
·
IF 4
Shihui Wang,Zhoujun He,Ling Wu,Deling Wang,Ruiru Si,Xiyao Liu,Ruowen Liang
Due to their explicit structure, metal–organic frameworks (MOFs) have been supposed to be credible platforms to research the micro-mechanism of heterogeneous photocatalysis. In this study, amino-functionalized MOFs (MIL-125(Ti)–NH2 (denoted as MTi), UiO-66(Zr)–NH2 (denoted as UZr) and MIL-68(In)–NH2 (denoted as MIn)) with three different metal centers were synthesized and applied for the denitrification of simulated fuels under visible light irradiation, during which pyridine was used as a typical nitrogen-containing compound. The results showed that MTi had the best activity among the above three MOFs, and the denitrogenation rate increased to 80% after 4 h of visible light irradiation. On the grounds of the theoretical calculation of pyridine adsorption and actual activity experiments, it can be presumed that the unsaturated Ti4+ metal centers should be the key active sites. Meanwhile, the XPS and in situ infrared results verified that the coordinatively unsaturated Ti4+ sites facilitate the activation of pyridine molecules through the surface –N⋯Ti– coordination species. The coordination–photocatalysis synergism promotes the efficiency of photocatalytic performance and the corresponding mechanism is proposed.
研究领域:
材料科学
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环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2020
·
IF 3.573
Meijuan Chen,Xiaoyan Wei,Liaoliao Zhao,Yu Huang,Shun-cheng Lee,Wingkei Ho,Kehao Chen
Highly efficient and stable photocatalysts were synthesized at room temperature by modifying MIL-125(Ti) with N-doped carbon quantum dots (N/CM(Ti)). The N/CM(Ti) with 2.5 vol % N doped carbon quantum dots (N/CQDs) had the best light absorption and visible-light photocatalytic nitrogen oxide (NO) removal efficiency (approximately 49%). It was found through X-ray photoelectron spectroscopy analysis that a N–Ti–O bond was formed in the 2.5 vol % N/CM(Ti), which is more conducive to charge transfer. Photocurrent and electrochemical impedance data also showed that the carrier separation efficiency of 2.5 vol % N/CM(Ti) was significantly superior to that of MIL-125(Ti). In addition, the TiIII–TiIV of MIL-125(Ti) acts as the active center for photocatalytic removal of NO. Two possible electron migration paths were proposed: electron transfer from N/CQDs to TiIII–TiIV center of MIL-125(Ti) due to the photoinduced electron transfer property of N/CQDs, and absorption of UV light generated from the N/CQDs by the terephthalic acid ligand followed by electron transfer to metal active sites for photocatalytic removal of NO.
研究领域:
材料科学
·
环境科学
·
化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COORDINATION CHEMISTRY
·
2023
·
IF 1.9
Jinyan Tan,Na Zhang,Ling Wang,Liduo Chen,Cuiqin Li,Jun Wang
Metal-organic framework MIL-125(Ti)-NH2 was prepared and coordinated with salicylaldehyde and NiCl2·6H2O to create a heterogeneous catalyst for ethylene polymerization. The structure of the products was characterized by a variety of physical methods, such as Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), inductively coupled plasma mass spectrometry (ICP-MS), and nitrogen adsorption-desorption. The catalytic performance of MIL-125(Ti)-NH2-Sal-Ni was also investigated. The results showed that the reaction temperature, Al/Ni molar ratio, and ethylene pressure influenced on the catalytic activity and product selectivity. Under optimal reaction conditions, the catalytic activity of MIL-125(Ti)-NH2-Sal-Ni for ethylene oligomerization could reach 5.90 × 104 g·(mol Ni·h)−1 using cyclohexane as the solvent and MAO as the co-catalyst; the main products were C4 and C6. In addition, MIL-125(Ti)-NH2-Sal-Ni had good catalytic stability and recycling, which could be reused at least twice without significant loss of activity. Moreover, based on the evaluation of catalytic performance, the catalytic ethylene oligomerization mechanism of MIL-125(Ti)-NH2-Sal-Ni was also deduced.
研究领域:
材料化学
·
催化化学
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产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2018
·Vol. 8
·期 7
·1936-1944
·
IF 5.365
Zhongmin Liu,Yongchuan Wu,Jitao Chen,Yaru Li,Jingyu Zhao,Kaihua Gao,Ping Na
A bifunctional cake-like TiO2 was successfully synthesized via calcination of MIL-125(Ti) at a suitable temperature by a one-step method and was applied for As(III) removal by simultaneous photocatalytic oxidation and adsorption. The as-synthesized samples were characterized by XRD, TGA/DSC, SEM, TEM, N2 adsorption–desorption isotherms, PL spectra, photocurrent, FTIR and XPS. The effects of calcination temperature on the specific surface areas of the samples, transformation of the TiO2 crystal phase and properties of As(III) removal were investigated. The results showed that higher calcination temperature resulting in a lower specific surface area and more transformations of the TiO2 crystal phase from anatase to rutile. The TiO2 calcined at 380 °C (MIL-125(Ti)-380 °C) exhibited excellent properties for As(III) removal, including photocatalytic oxidation of As(III) and simultaneous adsorption of the generated As(V). In addition, MIL-125(Ti)-380 °C could be reused at least four times without significant reduction in the photocatalytic oxidation and adsorption performances. The excellent photocatalytic oxidation and adsorption abilities of MIL-125(Ti)-380 °C can be attributed to the synergistic effects of strong photogenerated electron–hole separation and high specific surface area. The bifunctional cake-like TiO2 provides a wonderful strategy to remove As(III) completely from contaminated water using a single step.
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
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
·
2020
·
IF 4.652
Hailiang Li,Dechang Jia,Zhihua Yang,Xingqi Liao,Haize Jin,Delong Cai,Yu Zhou
Post heat treatment has been considered as an essential process to relieve residual stress, tailor the microstructure and obtain desired mechanical properties of the parts manufactured by selective laser melting (SLM) technology. The present work comparatively investigated the effect of heat treatment on microstructure evolution and mechanical properties of the SLM-fabricated Ti–6Al–4V alloy (Ti64) and 2 vol% TiB/Ti–6Al–4V titanium matrix composite (TMC). Microstructure analysis indicated that the as-built and heat treated TMC samples showed profoundly different microstructures compared to that of Ti64 samples . With heat treatment temperature increasing, the dominant acicular α′ martensite of Ti64 was decomposed into fine (α+β) lamella and microstructure coarsening occurred. A finer (α+β) dual-phase matrix microstructure, compared to that of Ti64, was achieved for TMC samples when heat treatment temperature exceeded 850 °C. The densely dispersed clusters of parallel nanoscale TiB precipitates of the TMC grew into individually separate TiB whiskers with larger nanoscale and sub-microscale size through a stacking up process of (100) planes based on an Ostwald ripening process. Mechanical testing results showed that the hardness and yield strength values of TMC samples before and after heat treatment were all higher than that of the Ti64 samples. A superior comprehensive mechanical performance with relatively high yield strength (1345 MPa) and significantly improved fracture strain from 17.6% to 31.3% was achieved for the TMC sample after heat treatment at 850 °C.
研究领域:
材料科学
·
金属加工工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Shengdong Sun,Hui Liu,Longlong Fan,Yang Ren,Xianran Xing,Jun Chen
Grain size effect plays a vital role in piezoelectric performance from both scientific and technological view. However, the underlying structural mechanism related to grain size is still unclear. In the present study, the structural mechanism of grain size effect on piezoelectric performance has been revealed in the prototype Pb(Zr,Ti)O 3 system by using in-situ synchrotron X-ray diffraction. The miniaturization of grain size tends to favor the appearance of higher symmetric tetragonal phase, while a single monoclinic phase is determined in the coarse-grained ceramics. The direct structural evidence reveals that both tetragonal and monoclinic phases in the fine-grained ceramics are less sensitive to the electric field, corresponding to the inferior piezoelectric performance, while the single monoclinic phase in the coarse-grained ceramics is more active to be driven by the electric field, generating good piezoelectric behavior. Both domain switching ability and lattice strain are suppressed with decreasing grain size, which directly leads to the deterioration in piezoelectric performance. The current results will benefit the structural understanding of the size effect of piezoelectric and other related systems.
研究领域:
材料科学
·
物理学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）