MOLECULES
·
2024
·Vol. 29
·期 24
·5981
·
IF 4.2
Lizhe Ma,Zhiyong Fang,Jieli Duan,Jin Li,Kefu Zhu,Yinlong Jiang,Bang Ji,Zhou Yang
TiO2has broad prospects in reducing the safety risks posed by emerging pollutants in water environments. However, the high recombination rate of photogenerated carriers limits the activity and photon utilization efficiency of TiO2. In this study, mesoporous TiO2(m-TiO2) and ultra-thin g-C3N4nanosheets were composited using a hydrothermal method, with the m-TiO2tightly and uniformly wrapped by g-C3N4. The chemical structure, elemental composition, and optical properties of the heterojunction were analyzed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), and ultraviolet-visible diffuse reflectance spectroscopy (UV-vis-DRS). The activity of the m-TiO2@g-C3N4was evaluated by the degradation of tetracycline hydrochloride (TCH). Results showed that the heterojunction exhibited significantly enhanced reactivity compared to pure m-TiO2and g-C3N4, with kinetic rates of TCH being 1.48 and 6.84 times that of pure m-TiO2and g-C3N4, respectively. The TCH degradation kinetic rate varied from 0.194 min−1to 0.026 min−1and then decreased to 0.015 min−1on the scale of the bandgap and the number of absorbed photons in m-TiO2@g-C3N4. Concurrently, a 10wt% doping amount of g-C3N4significantly increased the reaction rate of photogenerated carriers in the system compared to the recombination rate, corresponding to excellent photon efficiency. Reproducibility was evaluated, and a possible degradation mechanism is proposed. This study opens new perspectives for the optimization of catalyst preparation processes aimed at enhancing photon efficiency.
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
Cell Reports Physical Science
·
2020
·
IF 0
Pengfei Zhang,Zhangliu Tian,Chin-Te Hung,Yong Liu,Bingquan Jia,Kun Lan,Biao Kong,Fuqiang Huang,Liqiang Mai,Dongyuan Zhao
The understanding and control of the structural complexity of mesoporous semiconductors with single-crystal-like nature are both attractive and challenging. Here, we report a crystallization-driven epitaxial assembly from monomicelles to construct branched mesoporous TiO 2 mesocrystals (m-TiO 2 MCs) with coherent atomic domains. The star-shaped multipods are obtained by two-step evaporation with nanocrystal mediation, primarily consisting of arms along < 001 >, < 101 >, and < 111 > crystal directions. For each arm, ordered open mesochannels arrange in parallel along the growth direction. The m-TiO 2 MC multipods have a surface area of ∼116 m 2 /g and single-crystal-like frameworks and are good hydrogen evolution photocatalysts. Under full-spectrum irradiation, the branched m-TiO 2 MCs exhibit a hydrogen evolution rate of 8 mmol h −1 g −1 , which is more than four times higher than that of commercial TiO 2 P25. This crystallization-driven self-assembly approach may provide valuable insight into designing programmable mesoporous mesocrystals by controlling the oriented assembly of monomicelle building blocks.
研究领域:
材料科学
·
化学
✓ 已验证
DOI
CRYSTENGCOMM
·
2020
·Vol. 22
·期 23
·4030-4038
·
IF 3.117
Jin Yan,Lei Dai,Penghui Shi,Jinchen Fan,Yulin Min,Qunjie Xu
A limited light absorption range and low electron transfer efficiency have always been the major problems in semiconductor photocatalysis. Here, a defect-rich heterophase junction-containing TiO2 porous nanostructure was designed and synthesized to improve the low utilization rate of photoexcited carriers in photocatalysis. Defects were first introduced into titanium dioxide, and co-doping was used to obtain defect-rich materials. At the same time, heterophase junction TiO2 with anatase and rutile phases was obtained under temperature control. The TiO2 phase junction could significantly improve the interface charge recombination. These two synergistically regulated the hydrogen production favorably, thus improving the carrier separation efficiency and reducing the band gap from the ultraviolet to the visible region, which resulted in the construction of the most effective defects. Theoretical predictions and empirical characterizations indicate that TiO2 with defects introduced into it presents a porous structure, and the doped phase exposes the internal defects of the bulk phase of the material to the surface and adjusts the defect position. The experimental results confirmed that the synergistic effect of B and Rh co-doping increased the photocatalytic hydrogen production yield of TiO2 by 10 times. This study provides new insights into photocatalyst defect regulation.
研究领域:
材料科学
·
纳米技术
·
能源化学
·
光催化
·
半导体物理
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2022
·
IF 12.92
Huapeng Li,Bin Sun,Tingting Gao,Huan Li,Yongqiang Ren,Guowei Zhou
ABSTRACT Photocatalytic degradation and hydrogen production using solar energy through semiconductor photocatalysts are deemed to be a powerful approach for solving environmental and energy crisis. However, the biggest challenge in photocatalysis is the efficient separation of photo-induced carriers. To this end, we report that the mesoporous TiO 2 nanoparticles are anchored on highly conductive Ti 3 C 2 MXene co-catalyst by electrostatic self-assembly strategy. The constructed mesoporous TiO 2 /Ti 3 C 2 composites display that the mesoporous TiO 2 nanoparticles are uniformly distributed on the surface of layer structured Ti 3 C 2 nanosheets . More importantly, the as-obtained mesoporous TiO 2 /Ti 3 C 2 composites reveal the significantly enhanced light absorption performance, photo-induced carriers separation and transfer ability, thus boosting the photocatalytic activity . The photocatalytic methyl orange degradation efficiency of mesoporous TiO 2 /Ti 3 C 2 composite with an optimized Ti 3 C 2 content (3 wt%) can reach 99.6% within 40 min. The capture experiments of active species confirm that the •O 2 − and •OH play major role in photocatalytic degradation process. Furthermore, the optimized mesoporous TiO 2 /Ti 3 C 2 composite also shows an excellent photocatalytic H 2 production rate of 218.85 μmol g –1 h –1 , resulting in a 5.6 times activity as compared with the pristine mesoporous TiO 2 nanoparticles . This study demonstrates that the MXene family materials can be applied as highly efficient noble-metal-free co-catalysts in the field of photocatalysis .
研究领域:
材料科学
·
环境科学
·
能源科学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2015
·
IF 4.504
Yunpeng Zong,Yong Liu,Wenxia Zhao,Hao Zhang,Baojun Li,Xiang Zhou,Hui Shen
Herein, we report a simple base-free hydrothermal route for the synthesis of mesoporous TiO 2 fibers by using chitosan as direct agent. This hierarchical structure combines advantages of mesopores constructed by interconnected sub-10 nm nanocrystals on nanoscale and 1D structure with large aspect ratio on micron-scale, which is desired structural characteristic needed for the high-performance anode materials. Benefiting from such unique structural features, it demonstrates superior high charge/discharge capability, good cycling stability and rate capability when used as lithium-ion batteries electrode. For example, it can deliver a capacity of 174 mA h g −1 at 0.5C and 137 mA h g −1 at 5C after 100 cycles.
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
ChemCatChem
·
2023
·Vol. 15
·期 7
·e202201687
·
IF 4.5
Wenjing Xu,Yingying Cheng,Jing Hou,Peng Kang
Graphical Mesoporous TiO 2 spheres with large specific surface area were synthesized by a simple two-step method for the electrocatalytic reduction of oxalic acid. The maximum Faradaic efficiency for glycolic acid reached 73.9 % at −0.5 V at ambient temperature, exceeding most recently reported results. Reducing oxalic acid to glycolic acid electrochemically remains a significant challenge due to the high overpotential and low selectivity and stability. This study uses mesoporous TiO 2 spheres of anatase phase as catalysts to reduce oxalic acid to glycolic acid with low overpotential. The maximum Faradaic efficiency of glycolic acid reaches 73.9 % at −0.5 V vs RHE. The mesoporous structure not only increases the specific surface area, but also limits the escape of intermediate glyoxalic acid from the catalyst surface due to the space-limiting effect of the mesoporous channel, such that oxalic acid can be deeply reduced to glycolic acid. Moreover, a mechanism for oxalic acid reduction is proposed, and the Ti 3+ /Ti 4+ redox pair plays an important role in the reduction of oxalic acid.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Tengfei Wang,Qing Pang,Boyu Liu,Hongyu Wang
Titanium dioxide (TiO 2 ), once considered a promising material for microwave absorption, still faces significant challenges in achieving broadband absorption performance. To address this issue, herein, a simple approach is reported for successfully introducing defects and crystalline/amorphous heterostructures onto mesoporous TiO 2 (Meso-am-TiO 2-x ). This study demonstrates the superior microwave absorbing properties of Meso-am-TiO 2-x , particularly in the low-frequency range. A reflection loss of up to −25.7 dB is achieved with a thickness of 4.6 mm, and the effective absorption bandwidth (EAB) value extends to 4.32 GHz. The experimental results indicate that the synergistic effects of the high specific surface area of mesoporous TiO 2 , defects-induced conduction loss, defect-induced dipole polarization loss, and interfacial polarization loss between the crystalline and amorphous heterostructures enhance the microwave absorption properties of Meso-am-TiO 2-x . This study provides insights toward developing innovative low-frequency broadband TiO 2 absorbers.
研究领域:
材料科学
·
电磁学
✓ 已验证
DOI
高影响因子
FOOD CHEMISTRY
·
2015
·
IF 3.391
Lingtian Wu,Yi Liu,Bo Chi,Zheng Xu,Xiaohai Feng,Sha Li,Hong Xu
Sucrose isomerase (SIase) is the key enzyme in the enzymatic synthesis of isomaltulose. Mesoporous titanium dioxide (M-TiO 2 ) and ε-poly- l -lysine-functionalized M-TiO 2 (EPL-M-TiO 2 ) were prepared as carriers for immobilizing SIase. SIase was effectively immobilized on EPL-M-TiO 2 (SI-EPL-M-TiO 2 ) with an enzyme activity of 39.41 U/g, and the enzymatic activity recovery rate up to 93.26%. The optimal pH and temperature of immobilized SIase were 6.0 and 30 °C, respectively. SI-EPL-M-TiO 2 was more stable in pH and thermal tests than SIase immobilized on M-TiO 2 and free SIase. K m of SI-EPL-M-TiO 2 was 204.92 mmol/L, and v max was 45.7 μmol/L/s. Batch catalysis reaction of sucrose by SI-EPL-M-TiO 2 was performed under the optimal conditions. The half-life period of SI-EPL-M-TiO 2 under continuous reaction was 114 h, and the conversion rate of sucrose after 16 batches consistently remained at around 95%, which indicates that SI-EPL-M-TiO 2 has good operational stability. Thus, SI-EPL-M-TiO 2 can be used as a biocatalyst in food industries.
研究领域:
食品科学
·
生物化学
·
酶工程
✓ 已验证
DOI
PubMed
高影响因子
CHEMICAL PHYSICS
·
2024
·
IF 2
Xing-Fei Guo,Quan Li,Hai-Tao Ren,Jing Wang,Xu Han
Mesoporous TiO 2 with a homogeneous Bi-Ag bimetallic distribution (Bi@Ag@MTs) can be obtained by calcination of a titanium-based metal organic framework (MOF, MIL-125) with Bi and Ag loading and applied to the photocatalytic reduction of nitrate using formic acid as a hole scavenger. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscope (TEM) and energy dispersive spectrometer (EDS) analyses show that Ag(I) and Bi(III) are present in MTs as fine clusters and Bi@Ag@MTs have a specific pancake structure, which provides a good carrier for photocatalytic reaction. The contents of Ag and Bi in Bi@Ag@MTs can be up to 2.28 wt% and 0.54 wt% analysed by Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES). Under UV irradiation, Bi@Ag@MTs(0.2,0.4) showed a high reduction rate (3.28 h −1 , 4.2 times that of P25), high conversion (100 %, 1.3 times that of P25) and high N 2 selectivity (89.2 %, 2.1 times that of P25) for nitrate reduction. In addition, Bi@Ag@MTs(0.2,0.4) showed good reusability, with the respective NO 3 − conversion and N 2 selectivity still reaching 82.2 % and 78.0 % after four cycles. X-ray photoelectron spectroscopy (XPS) analysis showed that under UV irradiation, part of Ag(I) would be reduced to Ag 0 , and the formed Ag-Ag 2 O structure helped to improve the photocatalytic activity of the catalyst. This preparation strategy provides assistance in the design of photocatalytic materials with significant activity and durability for nitrate reduction.
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 ALLOYS AND COMPOUNDS
·
2018
·
IF 3.779
Zhong Li,Azhar Ali Haidry,BaoXia Dong,LinChao Sun,Qawareer Fatima,LiJuan Xie,ZhengJun Yao
Long range nitrogen doped ordered mesoporous TiO 2 (N-OMT) structures having pore size 3–4 nm and wall thickness ∼2 nm were synthesized via multi-component process and then characterized by XRD , Raman spectra, BET, SEM, TEM , and XPS . Afterwards, powders of N-OMT were sprayed on the ceramic substrates with Au interdigitated electrodes to apply as humidity sensors and conduct systematic dynamic humidity sensing tests under dark conditions and room temperature via a custom-made gas-sensing test system. High resistance variation (>10 5 ) towards 90% RH reveals its high sensitivity and application potential. The results indicate that nitrogen doping and mesoporous structure are synergistically conducive to enhancing the humidity sensing properties and evaporation induced self-assembly (EISA) strategy should be one of the most effective and significant approaches to prepare the higher performance humidity sensing materials. Based on the characterization and analysis, as well as the comparison with other sensors based on OMT and Commercial powders, a reasonable humidity sensing mechanism aim to explain the enhancement of N-OMT sensor's performances is discussed in detail.
研究领域:
材料科学
·
传感器技术
✓ 已验证
产品关联
DOI
高影响因子
Nanoscale
·
2017
·Vol. 9
·期 43
·16764-16772
·
IF 7.367
Yayun Hong,Chenlu Pu,Hongli Zhao,Qianying Sheng,Qiliang Zhan,Minbo Lan
In this work, we fabricated a yolk–shell magnetic composite that contains mesoporous TiO2 as the inner shell and flowerlike NiO as the outer shell (denoted as Fe3O4@H-TiO2@f-NiO) to reduce the limitations of single-component metal oxides in phosphopeptide enrichment. The NiO nanosheets play a synergistic role in phosphopeptide enrichment. And the unique flowerlike structure of NiO with sufficient space can facilitate the reversible insertion/extraction of peptides, which will have less impact on the enrichment process of the inner TiO2 shell. The yolk–shell structure and two types of porous nanostructures endowed this composite with a high surface area (156.58 m2 g−1) and a large pore volume (0.37 cm3 g−1). Owing to the high surface area and combined properties of TiO2 and NiO, the Fe3O4@H-TiO2@f-NiO microspheres showed a better performance for phosphopeptide enrichment than the same material without NiO nanosheets (Fe3O4@H-TiO2). According to the LC-MS/MS results, 972 unique phosphopeptides were identified from HeLa cell extracts with a high selectivity (91.9%) by Fe3O4@H-TiO2@f-NiO relative to 837 phosphopeptides (selectivity: 60.2%) by Fe3O4@H-TiO2. The results demonstrated that, compared with single-component metal oxides, composite metal oxides could enhance the selectivity and sensitivity for phosphopeptide enrichment.
研究领域:
生物化学
·
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2017
·
IF 2.084
Sumin Li,Hui Jiang,Tao Tang,Yijing Nie,Zhao Zhang,Qin Zhou
As a potential electrolyte for energy storage devices, mesoporous TiO 2 -doped epoxy-based composite electrolytes were fabricated. The presence of mesoporous TiO 2 in the composites promotes the cross-linking reaction of epoxy resin , as well as reduces the charge transfer resistance and favors the ionic transport, providing the composite electrolytes with enhanced electrochemical performance , mechanical strength and thermal stability. The highest ionic conductivity (11 × 10 −5 S cm −1 ), ionic transference number (0.661) and compression strength (5.06 MPa) were obtained for a composite electrolyte with 6 wt% doped mesoporous TiO 2 . The nano-structured reinforcing phase is beneficial to the enhancement in the electrochemical and mechanical performances of electrolyte simultaneously.
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
危险品化学品经营许可证（带存储）