APPLIED CATALYSIS B-ENVIRONMENTAL
·
2017
·
IF 9.446
Yaru Li,Zhongmin Liu,Yongchuan Wu,Jitao Chen,Jingyu Zhao,Fengmin Jin,Ping Na
Carbon dots-TiO 2 nanosheets (CDs-TNs) composites were synthesized by hydrothermal method and applied for the first time in photoreduction of Cr(VI) under sunlight illumination. The materials were characterized by transmission electron microscope, X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectrometer, and X-ray photoelectron spectroscopy analysis. The results confirmed that CDs are successfully incorporated with TNs through Ti O C bonds. With the introduction of CDs, CDs-TNs composites exhibit excellent photoreduction performance of Cr(VI), which is higher than that of TNs, P25 and CDs-P25. The unique upconversion property and electron transfer property of CDs play essential roles on light harvesting and charge carriers transferring in the photoreduction process. Most importantly, CDs could facilitate the formation of H 2 O 2 , leading to the consumption of holes. As a result, the recombination of photoinduced electron-hole pairs is hindered and photoreduction activity of CDs-TNs is promoted.
研究领域:
材料科学
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环境科学
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光催化
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产品关联
DOI
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
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2017
·Vol. 17
·期 2
·1204-1209
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IF 1.483
Zheng Yan,Wang Junpeng,Yang Ping
Anatase TiO2 with exposed {001} facets were synthesized via solvothermal method by using titanium (IV) butoxide as Ti source, hydrofluoric acid as capping agent and alcohol as solvent. Different alcohols such as methanol, ethanol, isopropyl alcohol, and n-butanol were investigated
systematically. As-prepared samples were characterized by X-ray diffraction, field emission scanning electron microscope and transmission electron microscope. The results indicated that regular TiO2 nanosheets were created from ethanol and isopropanol alcohol even though the size
and thickness changed. However, TiO2 nanosheets were attached together in methanol and n-butanol. The reasons of solvent effect the morphology and properties of TiO2 crystals exposed {001} facets have been discussed. The photocatalysis investigation of samples was carried
out by degradating methyl orange under ultraviolet light irradiation. TiO2 nanosheets obtained in ethanol solvent exhibited superior photocatalytic performance compared with other samples. The reasons could attribute to TiO2 nanosheets obtained in ethanol solvent with
higher specific surface area, mesoporous structure, and exposed highly active {001} facets.
研究领域:
材料科学
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环境科学
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DOI
PubMed
高影响因子
ACS Sustainable Chemistry & Engineering
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2019
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IF 6.97
Shizhen Liu,Yajun Wang,Shaobin Wang,Mingmu You,Song Hong,Tai-Sing Wu,Yun-Liang Soo,Zhenqing Zhao,Guiyuan Jiang,Jieshan Qiu,Baojun Wang,Zhenyu Sun
Photocatalysis shows a great potential for N2 fixation to NH3 under mild conditions, which intrigues increasing research attention in recent decades. To this end, the design of efficient photocatalysts is the key. Herein, we report the synthesis of single atom Ru decorated TiO2 nanosheets rich in oxygen vacancies. Single Ru sites greatly promoted photoreduction of aqueous N2 to NH3, affording an NH3 formation rate of 56.3 μg/h/gcat. We found that isolated Ru atoms likely weakened the hydrogen evolution, promoted absorption of N2, and also improved the charge carrier separation, which led to enhanced N2 photofixation.
研究领域:
材料科学
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环境科学
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DOI
高影响因子
Nanoscale
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2019
·Vol. 11
·期 15
·7465-7473
·
IF 6.97
Meng Zhang,Xuezhang Xiao,Xinwei Wang,Man Chen,Yunhao Lu,Meijia Liu,Lixin Chen
Transition metal compounds are one of the highly efficient types of catalyst for improving the reaction kinetics of hydrogen storage materials. Among all the transition metals, titanium and its compounds show great catalytic effects on magnesium hydride. In this study, for the first time, TiO2 nanosheets with exposed {001} facets were synthesized and doped into MgH2. The TiO2 nanosheet (NS)-doped MgH2 showed superior kinetic performance and the lowest desorption temperature. The onset temperature of MgH2 + 5 wt% TiO2 NS for the release of hydrogen was 180.5 °C and the corresponding peak temperature was 220.4 °C, which are much lower than those of pure MgH2 and also distinctly lower than those of MgH2 + 5 wt% TiO2 nanoparticles (NP). For the isothermal dehydrogenation analysis, the MgH2 + 5 wt% TiO2 NS could release 6.0 wt% hydrogen within 3.2 min at 260 °C and desorb 5.8 wt% hydrogen within 6 min at 240 °C. It is worth noting that the MgH2 + 5 wt% TiO2 NS can even release 1.2 wt% hydrogen at a temperature as low as 180 °C within 300 min. The hydrogenation kinetics of MgH2 + 5 wt% TiO2 NS is also greatly improved, which could absorb hydrogen within only a few seconds at mild temperature. It can take up 3.3 wt% hydrogen at 50 °C and 5.4 wt% at 100 °C within 10 s. It is demonstrated that the tremendous enhancement in reaction kinetics of MgH2 can be ascribed to the nanometer size and highly active {001} facets of anatase TiO2. The higher average surface energy can significantly reduce the hydrogen desorption activation energy of MgH2 to 67.6 kJ mol−1, thus easily improving the hydrogen desorption properties.
研究领域:
材料科学
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能源化学
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
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2023
·Vol. 47
·期 35
·16611-16620
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IF 3.3
Xin Mai,Ran Gao,Yeheng Zhang,Junnan Chen,Wensong Lin,Chengli Mai
(001)-TiO2/BiOI photocatalysts with microsphere morphology were synthesized by a solvothermal method. The (001)-TiO2/BiOI demonstrated highest photocatalytic performance for the RhB degradation rate of 0.049 min−1 under visible light, which is 5 and 7 times that of (001)-TiO2 and BiOI, respectively. The increased photocatalytic efficiency is due to the construction of heterojunctions, which promote the transportation of photo-generated carriers. The good photochemical stability of the prepared photocatalysts was demonstrated by cycling experiments. The radical quenching experiments show that ˙O2− and ˙OH are the principal active species in the photocatalytic reaction mechanism. Finally, a possible mechanism of p–n heterojunctions in the photocatalytic reaction process was proposed.
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
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2021
·Vol. 23
·期 12
·1-12
·
IF 2.253
Pan Meng,Teng Xuegang,Li Mengxia,Pan Xianfeng,Liao Qiyong,Cheng Wenxiang,Yang Renchun
TiO 2 nanosheets have a great potential in photocatalytic H 2 evolution, but they suffer from low catalytic activity at present. Although the surface modification has been extensively used to improve the catalytic performance, regulating the surface functional groups of TiO 2 nanosheets to enhance the photocatalytic activity has been largely overlooked. In this study, we attempt to tailor the surface properties of TiO 2 nanosheets by adjusting the surface functional groups so as to improve their photocatalytic H 2 production activity. With adding a small amount of alcohols in the synthesis system, the surface hydroxyl groups of TiO 2 nanosheets were regulated successfully. Interestingly, the TiO 2 nanosheets prepared with adding ethylene glycol possess the significantly more surface hydroxyl groups and exhibit a narrower bandgap, a higher hydrophilicity, and a slower recombination rate of photo-induced carriers than the conventional nanosheets. Benefit from these special properties, the ability of the hydroxyl-rich TiO 2 nanosheets to photocatalyze H 2 evolution is obviously improved.
研究领域:
材料科学
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能源化学
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DOI
高影响因子
Catalysts
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2019
·Vol. 9
·期 11
·927
·
IF 3.444
Aiguo Han,Mei Li,Shengbo Zhang,Xinli Zhu,Jinyu Han,Qingfeng Ge,Hua Wang
In recent years, defective TiO2-based composite nanomaterials have received much attention in the field of photocatalysis. In this work, TiB2was used as a precursor to successfully prepare Ti3+defective TiO2(TiO2-B) with a truncated bipyramidal structure by a one-step method. Then, the SnS2nanosheets were assembled onto the as-prepared TiO2-B through simple hydrothermal reaction. TiO2-B exhibits strong visible light absorption properties, but the recombination rate of the photo-generated electron-hole pair was high and does not exhibit ideal photocatalytic performance. Upon introducing SnS2, the heterojunction catalyst SnS2-Ti3+defective TiO2(SnS2/TiO2-B) not only possesses the strong light absorption from UV to visible light region, the lowest photo-generated charge recombination rate but also achieves a more negative conduction band potential than the reduction potential of CO2to CO, and thereby, exhibits the significantly enhanced selectivity and yield of CO in photocatalytic CO2reduction. Notably, SnS2/TiO2-B produces CO at a rate of 58 µmol·h−1·g−1with CO selectivity of 96.3% under visible light irradiation, which is 2 and 19 times greater than those of alone TiO2-B and SnS2, respectively. Finally, a plausible photocatalytic mechanism on SnS2/TiO2-B was proposed that the electron transfer between TiO2and SnS2follows the Z-scheme mode. Our results present an effective way to gain highly efficient TiO2based photocatalysts for CO2reduction by combining different modification methods of TiO2and make full use of the synergistic effects.Keywords:photocatalytic CO2reduction;TiO2nanoplates;SnS2nanosheets;Ti3+defective TiO2
研究领域:
材料科学
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环境科学
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产品关联
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2013
·
IF 2.206
Zhiqiao He,Qiaolan Cai,Ming Wu,Yuanqiao Shi,Huiying Fang,Lingdan Li,Jiancheng Chen,Jianmeng Chen,Shuang Song
In the present work, reduction of Cr(VI) induced by UV–visible light in aqueous solution was investigated. The aqueous medium contained TiO2 nanosheets and no additional reducing agents or hole scavengers. A hydrothermal method was used to synthesize fluorinated TiO2 nanostructures with various percentages of exposed {001} facets and initial F/Ti ratios. Fluorine-free TiO2 nanosheets were obtained by washing the TiO2 samples with NaOH solution. The surface fluorination facilitates the adsorption process by increasing the number of surface OH groups generated. Moreover, fluorination efficiently inhibits the recombination of photogenerated electron–hole pairs. The {001} facets have an indirect role in the photocatalytic reduction of Cr(VI) because oxidative dissolution of H2O occurring on {001} facets and Cr(VI) reduction occurring on {101} facets are simultaneous reactions. The optimal ratio of exposed {001} to {101} was found to be ∼72:18.
研究领域:
环境科学
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材料科学
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产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
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2021
·
IF 9.229
Deli Jiang,Yimeng Zhou,Qianxiao Zhang,Qi Song,Changjian Zhou,Xiangli Shi,Di Li
Photocatalytic reduction of CO2 toward eight-electron CH4 product with simultaneously high conversion efficiency and selectivity remains great challenging owing to the sluggish charge separation and transfer kinetics and lack of active sites for the adsorption and activation of reactants. Herein, a defective TiO2 nanosheet photocatalyst simultaneously equipped with AuCu alloy co-catalyst and oxygen vacancies (AuCu-TiO2–x NSs) was rationally designed and fabricated for the selective conversion of CO2 into CH4. The experimental results demonstrated that the AuCu alloy co-catalyst not only effectively promotes the separation of photogenerated electron–hole pairs but also acts as synergistic active sites for the reduction of CO2. The oxygen vacancies in TiO2 contribute to the separation of charge carriers and, more importantly, promote the oxidation of H2O, thus providing rich protons to promote the deep reduction of CO2 to CH4. Consequently, the optimal AuCu-TiO2–x nanosheets (NSs) photocatalyst achieves a CO2 reduction selectivity toward CH4 up to 90.55%, significantly higher than those of TiO2–x NSs (31.82%), Au-TiO2–x NSs (38.74%), and Cu-TiO2–x NSs (66.11%). Furthermore, the CH4 evolution rate over the AuCu-TiO2–x NSs reaches 22.47 μmol·g–1·h–1, which is nearly twice that of AuCu-TiO2 NSs (12.10 μmol·g–1·h–1). This research presents a unique insight into the design and synthesis of photocatalyst with oxygen vacancies and alloy metals as the co-catalyst for the highly selective deep reduction of CO2.
研究领域:
材料科学
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环境科学
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化学工程
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DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2015
·
IF 2.587
Zhiqiao He,Lixian Jiang,Da Wang,Jianping Qiu,Jianmeng Chen,Shuang Song
A series of fluorinated anatase TiO2 nanosheets with dominant {001} facets were synthesized to oxidize p-chlorophenol (PCP) and reduce Cr(VI) simultaneously under visible light. The {001}/{101} surface facets ratio of TiO2 was controlled by varying the initial HF concentration, and fluorine-free samples were obtained by alkaline-washing. A synergistic effect among TiO2, Cr(VI), and PCP was observed, which is ascribed to effective trapping of photogenerated electrons and holes by Cr(VI) and PCP, respectively. A maximum synergistic effect was obtained at a molar ratio of [PCP] to [Cr(VI)] of one. Using X-ray diffraction, X-ray photoelectron spectroscopy, electron paramagnetic resonance spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy, and Brunauer–Emmett–Teller analyses, the optimum ratio of exposed {001} to {101} facets for TiO2 was determined to be 80:20 because of selective transfer and charge balance of photogenerated carriers. Surface fluorination facilitates the formation of oxygen vacancies and unsaturated Ti atoms, which is useful for visible light activity induction, extending the lifetime of photogenerated electron-hole pairs, and enhancing the rate of PCP oxidation and Cr(VI) reduction.
研究领域:
环境科学
·
材料科学
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DOI
高影响因子
ACS Applied Electronic Materials
·
2024
·
IF 4.3
Zeyi Wu,Mengyao Su,Xiangyu Song,Denghua Li,Xinyuan Li,Jiajia Liu,Jiatao Zhang
Surface termination and defects of metal oxide semiconductors are crucial in the process of gas adsorption–desorption and signal transduction, thereby determining their sensing performance. Herein, a facile solvent-assisted surface engineering strategy was demonstrated to synthesize anatase TiO2 nanosheets (TNS) for an ultraviolet (UV) light-activated isopropanol (IPA) gas sensor. Surface-fluorinated TiO2 nanosheets (F-TNS) were first synthesized by the hydrofluoric acid-assisted hydrothermal method and followed by hydrothermally treating in Na2S solutions with different concentrations. The effect of the progressive removal of fluorides was discussed in detail based on X-ray photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS), electrochemical impedance spectroscopy (EIS), and in situ Fourier transform infrared (FTIR) spectroscopy analyses. Compared with F-TNS, the chemiresistive sensor based on the TNS with a trace amount of fluorine exhibited a 324% increase in the sensitivity to 50 ppm of isopropanol at 50 °C under UV irradiation (λ = 365 nm, 30 mW/cm2), while it exhibited a 45% decrease in the recovery time. The enhanced isopropanol sensing performance could be attributed to the high surface area, rational surface terminations, oxygen vacancies, and UV photoexcited charge carriers, which further modulate the surface reaction and charge transfer. These findings offer a facile strategy for the rational design of oxide-based sensing materials, which help in understanding the function of surface terminations and defects in gas sensing.
研究领域:
材料科学
·
传感器技术
·
表面化学
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DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 45
·19924-19932
·
IF 3.288
Yifan Liu,Zirui Yu,Shanshan Guo,Lulu Yao,Runze Sun,Xiuying Huang,Weirong Zhao
Transition metal (M = Cu, Fe and Ni) modified TiO2 nanosheets were synthesized via a microwave assisted hydrothermal method. The as-fabricated catalysts were characterized using X-ray diffraction (XRD), electron microscopy, X-ray photoelectron spectroscopy (XPS), nitrogen adsorption–desorption, UV-vis diffuse reflectance spectroscopy (DRS), photoluminescence emission (PL), transient photocurrent–time curves and electrochemical impedance spectroscopy (EIS). The results indicated that the loading of transition metals did not influence the crystal structure and morphology of anatase TiO2, while the specific surface area, the absorption in the visible region and the charge transfer were enhanced. In addition, photocatalytic nitrogen fixation over the transition metal modified TiO2 nanosheets was also evaluated. Under the irradiation of simulated sunlight, transition metal modified TiO2 exhibited better photocatalytic performance and stability than pristine TiO2. Among these samples, Cu/TiO2 with the optimal mass content of 1.0% achieved the best NH4+ generation performance and the evolution rate reached 6.78 mmol g−1 h−1 with the relative standard deviation of 2.33%. Furthermore, a plausible mechanism coupled with interfacial charge transfer (IFCT) over Cu modified TiO2 nanosheets was proposed in our present study.
研究领域:
材料科学
·
环境科学
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产品关联
DOI
高影响因子
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