Catalysis Science & Technology
·
2018
·Vol. 8
·期 15
·3876-3882
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IF 5.365
Xiaogang Liu,Yingpu Bi
Ti3+-doped TiO2 nanosheets with different percentages of exposed {001} facets were synthesized by aluminium (Al) reduction. The structure, crystallinity, morphology, and other properties of the as-prepared samples were characterized by X-ray diffraction, transmission electron microscopy, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy. Electron paramagnetic resonance spectra confirm the presence of paramagnetic Ti3+ species in the prepared Ti3+-doped TiO2. Under UV-visible light irradiation, all the Al-reduced TiO2 nanosheet samples exhibit higher photocatalytic hydrogen evolution, degradation of methyl orange (MO) and photoelectrochemical (PEC) performance than the non-reduced ones. The Al-TiO2-HF6 sample with the highest Ti3+ concentration and optimal exposed {001} facets exhibits the most excellent photoreactivity, which is mainly ascribed to the efficient transport and separation of photo-induced charge carriers resulting from the synergistic effects between Ti3+ doping and facet regulation.
研究领域:
材料科学
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环境科学
·
化学
✓ 已验证
DOI
高影响因子
COMPOSITE INTERFACES
·
2019
·
IF 2.025
Xueyi Zhu,Shuling Shen,Zhihong Tang,Junhe Yang
Ti3+-doped TiO2@C nanorods were prepared through a facile hydrothermal process. Na2Ti3O7 ultralong nanotubes and glucose were used as TiO2 precursor and carbon (C) source, respectively. During hydrothermal treatment, the hydrolysis of Na2Ti3O7 and polymerization of glucose induced the formation of TiO2 nanorods with a coating of carbon complex. At the same time, a part of Ti4+ was reduced to Ti3+ due to the rich hydroxyl groups in glucose. After calcination, an ultrathin carbon shell was formed on the surface of TiO2 nanorods. In this prepared composite, Ti3+ self-doped TiO2 nanorods work as photosensitizer to harvest solar energy to generate electron-hole pairs, the tight-binding interface between TiO2 nanorods and carbon shell works as electron transportation path, and the ultrathin carbon shell acts as electrons trapped and accumulated site. Photocatalytic test results indicate that Ti3+-doped TiO2@C nanorods exhibit higher activity and stability than TiO2 for photodegradation of methylene blue under visible light.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Zhihua Tian,Fushuo Wu,Peiying Hu,Jianxiang Ding,Yan Zhang,Peigen Zhang,ZhengMing Sun
The properties of MAX phases can be fine-tuned to meet some particular applications via solid solution route, and the feasible preparation of the MAX solid solutions is a prerequisite for their applications. Ti 3 (Sn x Al 1−x )C 2 solid solutions over the whole composition range (x = 0–1) are synthesized by pressureless sintering, and characterized by XRD and SEM. The composition and crystal structure of representative Ti 3 Sn 0.8 Al 0.2 C 2 are examined by HRTEM, HAADF and EDS associated with STEM, and thus the Sn-rich Ti 3 (Sn x Al 1−x )C 2 solid solution is confirmed. Combined with means of thermal analysis, the reaction path for the formation of the Sn-rich Ti 3 (Sn x Al 1−x )C 2 solid solution is explored. Solid solutions are found to form with TiC as the nucleus and grow by reacting with Ti–Sn/Ti–Al intermetallic compounds . This work proves that the Ti 3 (Sn x Al 1−x )C 2 over the whole composition range, in particular, the Sn-rich end of this series of solid solutions can be obtained by the simple pressureless sintering, and would enable the fine manipulation of the composition of these typical MAX solid solutions for technologically important applications.
研究领域:
材料科学
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固体物理
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Haijun Chen,Jie Liang,Li Li,Baozhan Zheng,Zhesheng Feng,Zhaoquan Xu,Yonglan Luo,Qian Liu,Xifeng Shi,Yang Liu,Shuyan Gao,Abdullah M. Asiri,Yan Wang,Qingquan Kong,Xuping Sun
Electrocatalytic nitrogen reduction reaction (NRR) enabled by introducing Ti3+ defect sites into TiO2 through a doping strategy has recently attracted widespread attention. However, the amount of Ti3+ ions is limited due to the low concentration of dopants. Herein, we propose Ti2O3 nanoparticles as a pure Ti3+ system that performs efficiently toward NH3 electrosynthesis under ambient conditions. This work has suggested that Ti3+ ions, as the main catalytically active sites, significantly increase the NRR activity. In an acidic electrolyte, Ti2O3 achieves extraordinary performance with a high NH3 yield and a Faradaic efficiency of 26.01 μg h–1 mg–1 cat. and 9.16%, respectively, which are superior to most titanium-based NRR catalysts recently reported. Significantly, it also demonstrates a stable NH3 yield in five consecutive cycles. Theoretical calculations uncovered that the enhanced electrocatalytic activity of Ti2O3 originated from Ti3+ active sites and significantly lowered the overpotential of the potential-determining step.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF CATALYSIS
·
2017
·
IF 6.844
Siyu Tan,Zipeng Xing,Jiaqi Zhang,Zhenzi Li,Xiaoyan Wu,Jiayi Cui,Junyan Kuang,Qi Zhu,Wei Zhou
Ti 3+ self-doped TiO 2 /g-C 3 N 4 mesostructured nanosheets heterojunctions (Ti 3+ -TiO 2 /Meso-g-C 3 N 4 ) have been prepared via calcination-sonication assisted method using amino cyanamide as precursors, combined with a solid-state chemical reduction method. The Ti 3+ -TiO 2 /Meso-g-C 3 N 4 heterojunctions with narrow band gap of ∼2.21 eV possess relative high surface area of ∼73.8 m 2 g −1 , and large pore size of ∼10 nm. Remarkably, the Ti 3+ -TiO 2 /Meso-g-C 3 N 4 heterojunctions exhibit excellent visible-light-driven photocatalytic activity for degradating phenol in wastewaters. The photocatalytic hydrogen production rate of Ti 3+ -TiO 2 /Meso-g-C 3 N 4 heterojunctions rise to ∼290.2 μmol h −1 g −1 , which is about 4 and 14 times higher than that of the bare Meso-g-C 3 N 4 and TiO 2 , respectively. The enhanced photocatalytic activity may be ascribed to the synergetic effect of the mesoporous structure providing sufficient surface active sites, and Ti 3+ self-doping and the formed heterojunctions promoting the spatial separation of photogenerated electron-hole pairs.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2022
·
IF 4.326
Yunxia Bai,Mei Li,Xuemei Liu,Jinyu Han,Xinli Zhu,Qingfeng Ge,Hua Wang
Photocatalytic CO2 reduction is a promising route to simultaneously address two critical issues related to the energy and environment. Herein, a direct Z-scheme photocatalytic system, Ti3+ defective TiO2/CdS nanoflowers, was fabricated to enhance the production of C1–C3 products from CO2 reduction. First, nanoflower-like TiO2 (NF-TiO2) is prepared using a TiB2 precursor to build in Ti3+ defects. Then, the NF-TiO2/CdS heterojunctions are constructed via the sulfurization of TiO2/Cd-MOF. Importantly, the optimal heterojunction photocatalyst NF-TiO2/CdS0.6 exhibits a highly promoted CO2 reduction activity not only for CO and CH4 but also for C2–C3 hydrocarbons. The cumulative yields of CO and CH4 are 1007.0 μmol/g and 83.5 μmol/g (2.5 h), respectively, and a yield of 55.3 μmol/g (2.5 h) of C2–C3 hydrocarbons is obtained. This enhanced yield of C1–C3 products is attributed to the synergistic effects of abundant Ti3+ defects that increase adsorption and activation of CO2, the large surface area that provides sufficient active sites, and a direct Z-scheme heterojunction with a good intimate contact interface that effectively separates charge carriers and accumulates electrons with strong reducibility. Moreover, the photoluminescence analysis of hydroxyl radicals was conducted to provide evidence for the direct Z-scheme mechanism. This work provides a facile method for the construction of a TiO2-based direct Z-scheme photocatalytic system for improving photocatalytic performance toward CO2 reduction.
研究领域:
材料科学
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环境科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materiomics
·
2019
·
IF 0
Ping Wen,Ying Zhang,Guang Xu,Di Ma,Ping Qiu,Xiaoxia Zhao
Most of TiO 2 particles can be used as a photocatalyst for the selective oxidation of cyclohexane under ultraviolet light illumination. In this paper, Ti 3+ self-doped TiO 2 submicron-sized particles (i.e., Ti 3+ /TiO 2 SMP) were used as a catalyst for visible-light driven photocatalytic cyclohexane oxidation. The microstructure and properties of the Ti 3+ /TiO 2 SMP were characterized by X-ray diffraction (XRD), UV–visible diffuse reflection (UV–Vis DRS), scanning electron microscopy (SEM), electron paramagnetic resonance (EPR), solid-state photoluminescence spectroscopy (PLS) and X-ray photoelectron spectroscopy (XPS). The Ti 3+ /TiO 2 SMP exhibits good visible-light driven photocatalytic performances for cyclohexane oxidation with cyclohexanone as a dominate product. Effects of solvent, reaction temperature, reaction time and oxygen pressure on the formation of cyclohexanone were investigated. The cyclohexane oxidation over the Ti 3+ /TiO 2 SMP photocatalyst using carbon tetrachloride as a solvent under the optimal conditions presents a greater selectivity to cyclohexane (i.e., 95.1%). Based on the controlled experimental results with different radical scavengers, the hole (h + ) is critical for the activation of cyclohexane.
研究领域:
材料科学
·
催化化学
✓ 已验证
DOI
APPLIED SURFACE SCIENCE
·
2018
·
IF 4.439
Lina Kong,Xintong Zhang,Changhua Wang,Jianping Xu,Xiwen Du,Lan Li
Artificial direct Z-scheme system is promising in solar-fuel production owing to their efficient charge separation and high redox capability. However, direct Z-scheme system suffers from how to construct reasonable interfacial charge transfer channel for selective charge recombination. Here we fabricate a direct Z-scheme system consisting of g-C 3 N 4 crumpled sheet with Ti 3+ -doped TiO 2 nanoparticles via polycondensation of urea with TiO 2 followed by hydrogenated treatment. UV–vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy (XPS) and electron paramagnetic resonance (EPR) manifest that the hydrogenated treatment conferred Ti 3+ defect states below the conduction band minimum (CBM) of TiO 2 and improved visible light absorption of the g-C 3 N 4 /Ti 3+ -doped TiO 2 composite. The g-C 3 N 4 /Ti 3+ -doped TiO 2 exhibits remarkable photocatalytic performance for water splitting and degradation of pollutants than that of g-C 3 N 4 /TiO 2 , C 3 N 4 , and TiO 2 . The H 2 evolution rates of g-C 3 N 4 /Ti 3+ -doped TiO 2 reach up to 1938 and 287 μmol·h −1 ·g −1 under solar-light and visible-light irradiation, which is 3.4 and 2.8 times higher than that of g-C 3 N 4 /TiO 2 . The enhanced photocatalytic activity is ascribed to the Ti 3+ defects assistant formation of g-C 3 N 4 /Ti 3+ -doped TiO 2 Z-scheme photocatalyst, which results in efficient interfacial charge emigration and separation. Our work points out the critical role of defects in construction of Z-scheme pathways for charge transfer and provides possibilities for developing the other efficient photocatalysts.
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
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2022
·
IF 5.518
Mengnan Nie,Chao Zhou,Weiwei Feng,Changhui Xin,Xin Yu,Qian Li
Self-doped Ti 3+ -TiO 2 and amorphous ZnS layers-coated Ti 3+ -TiO 2 nanostructures were successfully fabricated for via a calcination-ultrasonic synthesis strategy for organic pollutant degradation under visible-light illumination. The experimental results revealed that the synthesized Ti 3+ -TiO 2 clusters displayed efficient visible-light absorption and photocatalytic performance. It was also found that amorphous ZnS layers were formed on the coral-like Ti 3+ -TiO 2 clusters via an ultrasonic synthesis method, and the strongly combined interfaces greatly boosted the charge separation between ZnS layers and self-doped Ti 3+ -TiO 2 clusters. The synthesized Ti 3+ -TiO 2 @ZnS-15% heterojunction presented the highest photocatalytic activity with a rate constant of 0.03197 min −1 , approximately 9.87 times of commercial TiO 2 . In addition, the prepared Ti 3+ -TiO 2 @ZnS composites also exhibited highly boosted photocatalytic performance towards ciprofloxacin and tetracycline degradation under visible-light illumination compared with those of commercial TiO 2 , Ti 3+ -TiO 2 , and ZnS samples. Finally, the norfloxacin degradation pathways and visible-light photocatalytic mechanism over nanostructured Ti 3+ -TiO 2 @ZnS heterojunctions were suggested.
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
MATERIALS RESEARCH BULLETIN
·
2018
·
IF 2.873
Tianyu Zhao,Zipeng Xing,Ziyuan Xiu,Zhenzi Li,Liyan Shen,Yan Cao,Mengqiao Hu,Shilin Yang,Wei Zhou
CdS quantum dots (QDs)/Ti 3+ -TiO 2 nanobelts heterojunctions as 0D/1D architectures are fabricated through hydrothermal-chemical bath deposition combine with in-situ solid-state chemical reduction approach. The CdS QDs of ∼7 nm are loaded on TiO 2 nanobelts with width of 50–300 nm and several micrometers long, and the heterojunctions are formed efficiently. The prepared heterojunctions exhibit excellent photocatalytic performance for complete removal of methylene blue (∼99%) and hydrogen production efficiency (∼480.6 μmol h −1 ) under visible light irradiation, which are as high as 2 and 23 times than that of pristine TiO 2 nanobelts. The enhancement is attributed to the Ti 3+ self-doping and CdS QDs extend the photoresponse to visible light region and the formation of heterojunctions favor the spatial separation of photogenerated charge carriers. Therefore, the high-efficient 0D/1D heterojunction composites have potential applications in the field of environment and energy.
研究领域:
材料科学
·
环境科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2021
·Vol. 32
·期 18
·22910-22920
·
IF 2.478
Zhao Yuan,Zhang Mengqi,Wang Wei,Song Wenli,Jiang Kanrui,Zhang Xiaojuan
Ti 3+ /N-co-doped TiO 2 was successfully synthesized in situ by one-step hydrothermal method using tetrabutyl titanate (TBOT) as the titanium source and hydrazine hydrate as the reducing agent and nitrogen source. Afterward, the microstructure and physicochemical properties of the catalysts were characterized by transmission electron microscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, UV–vis diffuse reflectance spectroscopy, and photoluminescence spectroscopy. Results indicated that nitrogen was effectively doped into the lattice of TiO 2 and Ti 3+ was stably presented in the prepared TiO 2 , which reduced the band-gap TiO 2 (2.96–2.75 eV) and enhanced photo-induced charge separation efficiency under visible light. In addition, the photocatalytic activity was evaluated by degradation of rhodamine B under xenon lamp with 420 nm filter. With the amount of hydrazine hydrate increased, the photocatalytic degradation performance of the sample increased first and then decreased. When the volume ratio of hydrazine hydrate to TBOT was 1:5, the sample showed the best photocatalytic performance.
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 Physical Chemistry C
·
2019
·
IF 4.309
Lina Lin,Yanling Ma,Jianbo Wu,Fei Pang,Jianping Ge,Song Sui,Yefeng Yao,Ruijuan Qi,Yan Cheng,Chun-gang Duan,Junhao Chu,Rong Huang
Colored titanium dioxide (TiO2) nanocrystals have been studied intensively in recent years due to their substantial solar-driven photocatalytic activities. Because of the scarcity of information correlated among atomic structure, electronic structure, and photocatalytic property from isolated nanoparticles, the origin of photocatalytic activity of colored TiO2 from microscopic and electronic level remains intensely debated. Here we demonstrated the origin of photocatalytic activity in Ti4+/Ti3+ core–shell TiO2 nanocrystals mainly by a combination of high-resolution transmission electron microscopy (HRTEM), electron energy-loss spectroscopy (EELS), and photo-Kelvin probe force microscopy (KPFM). The thickness of the Ti3+ shell layer increases with the annealing temperature, meanwhile the O/Ti atomic ratio of the outermost layer decrease. The differences in interplanar spacing between the surface and the subsurface generate strain effect, which increase carrier mobility and ultimately improve catalytic performance. Quantum size effect and specific surface area also have a big impact on catalytic performance. A prerequisite is to keep a good balance between the Ti4+/Ti3+ core–shell structure and the particle size to optimize its photocatalytic properties. By employing Au as a reference, we were able to estimate the Fermi levels of TiO2 before and after illumination. The amplitude of the Fermi level upshift unambiguously relates with the photocatalytic activity. The largest Fermi level upshift under illumination means generating the most efficient photoinduced carries to perform a highly catalytic reaction, carried out by optimizing the electronic structure with appropriate oxygen vacancies. But too many oxygen vacancies increase the recombination center and reduce the concentration of photoinduced electrons, which can also be observed from the photo-KPFM result.
研究领域:
材料科学
·
纳米技术
·
表面科学
✓ 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）