RESEARCH ON CHEMICAL INTERMEDIATES
·
2017
·Vol. 43
·期 8
·4353-4368
·
IF 1.369
Yuan Hong,He Jie,Li Ruilan,Ma Xiaoqin
The solid acid catalysts SO 4
2− /TiO 2 were prepared by the impregnation technique under two preparation conditions which were different in calcination temperature and concentration of impregnation solution of H 2 SO 4 . The characterization was carried out by using Fourier transform infrared spectrometer (FTIR), X-ray diffraction (XRD), temperature programmed desorption of NH 3 (NH 3 -TPD), N 2 -BET, X-ray fluorescence and thermal gravity (TG)–differential scanning calorimetry (DSC). The characteristic peaks in the FTIR spectrum were essentially the same within the calcination temperature range of 400–600 °C. The XRD results indicated that the sample could show partial specific peaks of the anatase phase as the calcination temperature was higher than 400 °C. The obvious strong acid and superacid sites of the prepared SO 4
2− /TiO 2 were conformed by the NH 3 -TPD results. The BET surface areas of 102–206 m 2 /g were measured by the N 2 -BET method, and the pore size distributions were essentially mesoporous. The TG–DSC results showed that SO 4
2− /TiO 2 would decompose at about 500 °C in the air. The solid acid SO 4
2− /TiO 2 were used for the epoxidation of castor oil. The lowest iodine value of the product was 52.65/100 g when the reaction temperature was 65 °C, reaction time was 10 h and catalyst loading was 15 wt.%.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
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
✓ 已验证
DOI
高影响因子
Materials
·
2025
·Vol. 18
·期 7
·1550
·
IF 3.2
Ke Wang,Weifeng Li,Yumei Long
As an environmentally friendly and clean energy technology, solar-driven interfacial evaporation technology has attracted wide attention. However, organic pollutants can easily pollute distilled water during the evaporation of wastewater. In this work, we report a strategy of N-TiO2/C solar absorption with a low bandgap (2.33 eV), excellent light absorption ability, and high photothermal conversion efficiency (48.2%). Black N-TiO2/C was prepared by the sol-gel method in the presence of hexamethylenetetramine as a source of nitrogen and carbon. The simultaneous N doping and C with superior photothermal effect rapidly increased the surface temperature of the material, reduced the recombination rate of electrons and holes, and improved the photocatalytic activity, showing great potential for solar thermal energy conversion. The prepared solar absorbent and polyurethane (PU) were mixed evenly to form a porous N-TiO2/C/PU (NTCP) foam for purifying water. The evaporator produced clean water at a rate of 1.73 kg m−2h−1under the simulated sunlight of 1 sun irradiation. Meanwhile, the evaporator simultaneously photodegraded methylene blue (MB) and rhodamine B (RhB) underwater at a removal rate > 90%. The bifunctional solar water evaporation device combining photocatalytic and photothermal effects holds great potential for water purification.
研究领域:
环境科学
·
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROPOROUS AND MESOPOROUS MATERIALS
·
2014
·
IF 3.209
Jimin Du,Zhiyong Wang,Guoyan Zhao,Yongteng Qian,Huijuan Chen,Jie Yang,Xinghui Liu,Kaidi Li,Chenxi He,Weimin Du,Imran Shakir
Herein, we report a facile route of synthesis that includes sol–gel method followed by the high temperature calcination with the aim to synthesize porous Sn/Nd-codoped TiO 2 monoliths with crystallized anatase walls using polystyrene spheres as template. Our results showed that both Sn and Nd dopant were well dispersed in the host matrix of the final product. Moreover, this as-synthesized porous Sn/Nd-codoped TiO 2 composite showed relatively narrow band gap compared to the pure anatase phase of TiO 2 , which may have its origin from the contributions from the Sn 4+ and Nd 3+ impurities. Interestingly, beside the narrowing of band gap in the codoped TiO 2 , the doping also have a positive effect to help reduced the charge recombination rate, which can be seen from the enhanced lifetime of photogenerated electrons/hole pairs. Finally, the photocatalytic activity of this interesting porous Sn/Nd-codoped TiO 2 monolith was examined by carrying out the dye degradation experiments on methyl orange under UV–vis irradiation. The porous Sn/Nd-codoped TiO 2 monolith showed better catalytic activity than the pure TiO 2 and Degussa P25 due to its narrow band gap, reduced photoinduced h + /e − pair recombination rate, and relatively large surface area. The synergistic combination of doping and surface area enhancement (porous structure) can be adopted as a promising material design strategy to develop photocatalyst materials for degradation of organic pollutants.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2018
·
IF 8.097
Liang Chen,Wei Tian,Chaoxiang Sun,Fengren Cao,Liang Li
To meet the demands of next-generation optoelectronic circuits, the design and construction of photodetectors with a tunable photoresponse range and self-powered feature are urgently required. To achieve selective wavelength detection, a band-pass filter is usually required to dislodge the interference of a certain wavelength light, which inevitably enhances the weight and increases the cost. Here, we demonstrate a self-powered photodetector with a tunable response range by constructing a heterojunction structure consisting of poly(3-hexylthiophene) (P3HT), a TiO2 interlayer, and silicon nanowires. By controlling the P3HT concentration, both core–shell and embedded configurations can be obtained, which exhibit different response ranges. This work provides a convenient route to construct self-powered wavelength-selective photodetectors, which may find applications in light communication and biomedical engineering.
研究领域:
材料科学
·
光电工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CRYSTENGCOMM
·
2016
·Vol. 18
·期 45
·8756-8761
·
IF 3.849
Zhiqiang Cheng,Shengzhe Zhao,Zhaolian Han,Yingying Zhang,Xiaodong Zhao,Lijuan Kang
Hollow TiO2 nanotubes have been produced by combining electrospinning with a soaking process and controlled calcination method. Silver was successfully coated on the surface of the TiO2 tubes through the immersion burning method. Structure and components of TiO2 and Ag/TiO2 tubes were characterized by X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX) and X-ray photoelectron spectroscopy (XPS). Morphology was studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The photocatalysis properties were verified by degradation of methyl orange (MO) dye. From the results, the Ag/TiO2 hollow tubes could degrade methyl orange efficiently under UV light irradiation, showing excellent photocatalytic activity over pure TiO2. The synthesis mechanism of the Ag/TiO2 tubes and the mechanism for silver-enhanced photocatalytic activity have been conjectured.
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
Sustainability
·
2023
·Vol. 15
·期 2
·1403
·
IF 3.9
Xueqiao Mei,Han Yuan,Chunhu Li
As the efficient catalysts are synthesized by a simple strategy, photocatalysis offers a sustainable route to solve the problem of environmentally sound treatment of industrial dye wastewater. Herein, Pt-doped TiO2with MIL-125 as the backbone has been fabricated using thermal synthesis. The photocatalytic efficiency of the synthesized catalyst samples was tested using Rhodamine B (RhB) as the contaminant model. The physicochemical properties of the solid specimens were characterized using XRD, SEM, TEM, BET and EDX techniques. The photocatalytic degradation experiments showed that the photocatalytic degradation of RhB by M-Pt-TiO2was 98.97% after 30 min of degradation. The radical capture experiments showed that superoxide radicals and conduction band electrons as reactive oxygen species played a major role in the degradation process. After four cycles, the photocatalytic activity of M-Pt-TiO2decreased from 98.4% to 94.9%, indicating that the photocatalyst sample had good photocatalytic stability.Keywords:metal-organic framework;Pt-TiO2;photocatalysis;dye wastewater;Rhodamine B
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
ACS Catalysis
·
2019
·
IF 12.221
Xiaoqiang Zhang,Peifang Yan,Bin Zhao,Kairui Liu,Mayfair C. Kung,Harold H. Kung,Shanyong Chen,Z. Conrad Zhang
The catalytic properties of physical mixtures of Ni particles (100–200 nm) with nanoparticles of anatase TiO2 (TiO2-A), ZrO2, Al2O3, rutile TiO2 (TiO2-R), and CeO2 were investigated for the hydrodeoxygenation (HDO) of guaiacol. High selectivities to phenolics were obtained only for Ni mixed with anatase TiO2 (Ni and TiO2-A), while saturated hydrocarbons were the main products for the mixtures with other supports. By thermal treatment in hydrogen gas only at 300 °C or higher and subsequently separating the large Ni particles from the TiO2-A particles with a magnet, it was further discovered that there was migration of TiO2 from TiO2-A onto the large Ni particles, resulting in an amorphous TiO2 overlayer on the Ni particles as evidenced by high-resolution TEM, and vice versa, migration of Ni onto TiO2-A. The TiO2 overlayer rendered the Ni particles completely inactive as a hydrogenation/hydrodeoxygenation catalyst. Conversely, the small amounts of Ni (<1.5 wt %) migrated onto TiO2-A formed highly dispersed Ni, undetectable by high-resolution TEM (<2 nm), that were remarkably highly active for HDO of guaiacol, producing selectively phenolics. Such highly selective HDO catalysts could also be formed by incipient wetness impregnation of Ni in loadings above 2 wt % onto the TiO2-A, but it was essential to pretreat the sample in H2 at 300 °C or higher. Pretreatment in H2 at 200 °C generated catalysts that produced saturated ring products. The activity of the impregnated catalysts, as measured by guaiacol conversion, increased linearly with Ni loading below 0.5 wt %. The activity continued to increase with Ni loading but more slowly up to 2 wt %, beyond which there was little further change. The results suggested that two types of Ni species existed on the TiO2-A surface. One type consisted of a cluster of Ni atoms that were dominant on larger Ni particles that were active in aromatic ring hydrogenation and hydrodeoxygenation. They were readily covered by reducible TiO2-A at 300 °C or higher due to the traditional strong metal support interaction (SMSI) effect and became inactive. Another type was clusters of a very small number of Ni atoms, perhaps one atom, that were present as highly dispersed Ni clusters interacting strongly with the defect sites of TiO2-A. The strong interaction of this type of Ni with the TiO2 defect deterred TiOx migration allowing surface exposed Ni atoms to catalyze the HDO of guaiacol with very high selectivities that were not characteristic of typical Ni particles.
研究领域:
催化化学
·
能源化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2011
·Vol. 13
·期 20
·9232-9237
·
IF 3.454
Jingjie Cui,Dehui Sun,Weijia Zhou,Hong Liu,Peiguang Hu,Na Ren,Haiming Qin,Zhen Huang,Jianjian Lin,Houyi Ma
Two kinds of TiO2 nanobelts were prepared from commercial P-25 powders via an alkaline hydrothermal method with and without an acid etching process. The uncauterized nanobelts (TNs) exhibited a smooth surface, and mixed phases of anatase and TiO2 (B), whereas the cauterized ones (CTNs) displayed a rough surface and a pure anatase structure. TNs and CTNs were then deposited onto a glassy carbon electrode (GCE) surface with a conductive adhesive (CA), and the resulting chemically modified electrodes exhibited electrocatalytic activities in the oxidation of nucleobases in a 0.1 M phosphate buffer solution (PBS) at pH 7.4. For guanine and adenine, well-defined oxidation peaks were observed in voltammetric measurements at about +0.62 and +0.89 V, respectively, at a potential sweep rate of 100 mV s−1, whereas for cytosine, uracil and thymine, the voltammetric features were not obvious. The average surface coverages (Γ) of guanine and adenine on the CTNs/CA/GCE electrode were estimated to be 4.75 × 10−10 and 7.44 × 10−10 mol cm−2, respectively, which were about twice those at the TNs/CA/GCE electrode. The enhanced activity of the CTN-based electrode towards purine nucleobase oxidation was ascribed to the large specific surface area and anatase structures with enhanced (001) facets of the CTN that facilitated adsorption of the analytes onto the electrode surface and charge transport through the electrode surface layer.
研究领域:
分析化学
·
纳米材料科学
·
电化学
·
生物传感
·
分子生物学
·
生物医学工程
✓ 已验证
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
CERAMICS INTERNATIONAL
·
2025
·
IF 5.6
Keyu Chen,Yu He,Bixuan Zhu,Chuanyezi Cai,Jiacheng Guo,Ruiqi He,Xi Chen,Lu Ye,Jianjun Zhang,Sude Ma
As the communications industry continues to develop, low temperature co-fired ceramics are used as resonators in multilayer chip components of integrated circuits. In order to co-fire with the metal, it is necessary to reduce the sintering temperature of ceramics to below 960 °C. In order to rule out the impact of changes in the operating temperature of the ceramic material, we need to adjust the resonant frequency temperature coefficient to near zero. This paper discusses the application of a temperature-stable low-temperature sintered dielectric material derived from Li 2 ZnSiO 4 (LZS) in low-temperature co-fired ceramics (LTCC). The addition of the low melting point oxide Bi 2 O 3 resulted in a significant reduction of the sintering temperature and improvement of the densification of LZS ceramics, where the sintering temperature was reduced from 1200 °C to 900 °C. The relative density and microwave dielectric properties (dielectric constant ε r , quality factor Q × f and temperature coefficient of resonant frequency τ ƒ ) of LZS- x Bi 2 O 3 ( x = 0, 3, 6, 9, 12 mol%) ceramics sintered at different temperatures increase and then decrease with increasing Bi 2 O 3 content. The best performance was obtained when the Bi 2 O 3 addition was 9 mol% (ε r = 6.87, Q × f = 28,151 GHz, τ ƒ = - 85.2 ppm/°C). By increasing the amount of TiO 2 added to LZS-9 mol%Bi 2 O 3 , the τ ƒ value of the ceramic system can be continuously increased, which is effectively adjusted to near zero. The best integrated dielectric properties of the LZS-Bi 2 O 3 -TiO 2 ceramic system (ε r = 8.9, Q × f = 22.982 GHz, τ ƒ = - 8.34 ppm/°C) are obtained when the TiO 2 addition is 30 wt%. This suggests that LZS-Bi 2 O 3 -TiO 2 ceramics have potential for low-temperature co-fired ceramics (LTCC) applications.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Environmental Sciences
·
2024
·
IF 5.9
Chunying Li,Yu Zhang,Mengfei Tian,Naveed Ahmad,Kaitao Jia,Zidan Luo,Bin Qiao,Jiabo Cheng,Chunjian Zhao
Porphyrinic hydrogen-bonded organic frameworks (porph-HOFs) have emerged as highly promising materials in the realm of photocatalysis due to their remarkable attributes, including low density, high surface area, efficient visible light absorption, and notable chemical stability. However, the rapid recombination of photogenerated charges remains a significant concern. In this work, a novel HOF-based photocatalyst, PFC-72/TiO 2 was successfully designed with visible light response and high electron transfer capability. This involved bonding TiO 2 nanoparticles to the PFC-72 framework synthesized using cobalt porphyrin as organic ligand and introducing bridging molecules 4-mercaptopyridine (4-PySH). Moreover, sulfadiazine (SDZ), a highly prevalent antibiotic, was effectively degraded from wastewater using PFC-72/TiO 2 . The high specific surface area of PFC-72 significantly improved the dispersion of TiO 2 in PFC-72/TiO 2 , providing more active sites and improving the ability to adsorb SDZ. Characterizations and density functional theory analysis further confirmed that the photosensitization effect of porph-HOF extended the response range of TiO 2 in PFC-72/TiO 2 and reduced the recombination efficiency of photogenerated charges, consequently enhancing photocatalytic performance. Additionally, due to significantly improved robustness of PFC-72 and its axial coordination interaction with 4-PySH, PFC-72/TiO 2 displayed excellent stability and recyclability. Consequently, optimized PFC-72/TiO 2 exhibited a remarkable SDZ removal efficiency of 93.73% within 120 min, maintaining consistent photoactivity even after undergoing four cycles. Furthermore, intermediate products and degradation pathways were proposed based on UPLC-MS/MS.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）