JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2018
·
IF 5.091
Jiabai Cai,Xueqing Wu,Yuehai Li,Ye Lin,Hui Yang,Shunxing Li
The goal of this work was to assess the performance of Pt nanoparticles (NPs) as co-catalysts on the photocatalytic activity of TiO 2 @Pt@C 3 N 4 hollow spheres, which was tested by photodegrading rhodamine B and methyl blue under visible light irradiation. TiO 2 @Pt@C 3 N 4 composites were fabricated by using modified polystyrene balls as templates, hydrothermal reactions , and calcination . Under simulated sunlight irradiation, photocatalytic activity was in the following of TiO 2 @Pt@C 3 N 4 > TiO 2 @C 3 N 4 > C 3 N 4 > P25. The photo-conversion rate of the TiO 2 @Pt@C 3 N 4 increased significantly relative to TiO 2 @C 3 N 4 and the others. The combination of TiO 2 and C 3 N 4 , as well as the sandwiched of Pt NPs reduce electron-hole recombination as a result of having an electron trap site, which can store and shuttle photo-generated electrons, and enhance photo-generation of active radicals. Electron paramagnetic resonance (EPR) spectroscopy, as well as photo-luminescence (PL), and electrochemical measurements were taken to verify this conclusion. Considering the multi-functional combination of precious metals and semiconductor materials , this work may provide new ideas for the design of high-performance catalysts.
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PubMed
高影响因子
FERROELECTRICS
·
2018
·
IF 0.728
Yuguo Zhuo,Jun Liu,Qingshan Li
Nano-TiO2/MDI-50 based waterborne polyurethane composites were prepared with MDI-50, polypropylene glycol (PPG) and nano-TiO2 as main materials. Nano-TiO2 was modified using r-aminopropyltriethoxysilane (KH550) as modifier in order to improve the dispersion of nano-TiO2 in WPU. The composites morphologies and physical states were investigated using scanning electron microscopy (SEM), thermogravimetry analysis (TG), fourier transform infrared (FTIR) spectroscopy and UV-visible (UV-Vis) spectroscopy. Scanning electron microscopy observations revealed that modified nano-TiO2 has good dispersibility. Results from FTIR and TG suggested that the modified nano-TiO2 had been successfully introduced to the polyurethane molecular chain and the thermal decomposition temperature of nano-TiO2/MDI-50 based waterborne polyurethane composites doubled under the same thermal weight loss. Results from UV-Vis suggested that when 2% of modified nano-TiO2 was added, maximum absorbance of composites were significantly improved and was twice higher than that of pure waterborne polyurethane.
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高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2018
·
IF 3.306
Qing Li,Xiaofang Zhu,Ying Zhang,Zhigang Zak Fang,Shili Zheng,Pei Sun,Yang Xia,Ping Li,Yang Zhang,Xing Zou
Hydrogen assisted magnesiothermic reduction (HAMR) of TiO 2 is a promising new process developed recently to produce Ti metal with low cost and less energy consumption. This work focuses on the understanding and optimization of the reduction process to control the quality of the reduced product. TiO 2 precursor particles with different relative densities were prepared, and the effects of the relative densities on reduction by Mg in H 2 were studied. The changes of oxygen contents vs. reduction time at various temperatures were investigated. The phase transformations during the reduction were analyzed both theoretically and experimentally. The relationship between the morphology of the reduced products and the relative densities of the TiO 2 precursors was analyzed by SEM characterization and the likely reason for the morphology evolution was discussed.
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高影响因子
NANO
·
2018
·
IF 1.1
Kaidi Li,Fangfang Zhang,Huiming Wang,Yalan Zhou,Lixin Zhao,Jimin Du,Yating Gao,Weimin Wang,Dae Joon Kang
Here, the lamellar-shaped Bi 2 S 3 grown on a porous TiO 2 monolith was obtained by a two-step method including a sol–gel route and hydrothermal treatment. The photocatalytic activity of the as-synthesized Bi 2 S 3 /TiO 2 composites was evaluated for photodegradation of methylene blue (MB) dye in aqueous solution under the visible-light irradiation. Based on our experimental results, 5% (molar ratio of Bi 2 S 3 to TiO 2 ) Bi 2 S 3 /TiO 2 photocatalysts exhibited a maximum photodegradation rate of MB up to 96.9% under visible-light irradiation for 120 min. Our findings indicated that the lamellar-shaped Bi 2 S 3 can extend the light absorption up to visible areas, and porous TiO 2 can provide enhanced specific surface area and more mass transfer pathway to enhance the photodegradation efficiency. Furthermore, porous TiO 2 can accept the electrons from the Bi 2 S 3 conduction band due to the relatively positive electrode potential to impede the photoproduced electron and hole combination to result in advanced photocatalytic performance.
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MATERIALS AND MANUFACTURING PROCESSES
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2019
·
IF 3.35
Tao Long,Yin Xu,Xiao-Jian Lv,Ming Li,Li Li,Lan-Ying Xu
A freestanding SiO2–TiO2 monolith with bicontinuous structure was prepared via a one pot sol-gel reaction. This monolith was fully characterized by using field emission scanning electron microscopy (FE-SEM), nitrogen adsorption and X-Ray diffraction (XRD). Synthesized SiO2–TiO2 monolith possesses great mechanical strength and interconnected macropores (throughpores, textural pores) on the micrometer scale as well as skeleton pores in nanoscale, and also possesses an anatase TiO2 crystalline structure. Photo-catalytic breakdown of aqueous methylene blue (MB) with UV light was chosen to evaluate photocatalytic efficacy of the SiO2–TiO2 catalyst. These photodegradation activities indicated that MB decomposed completely within 180 min and the SiO2-TiO2 catalyst was readily separated from the reaction system and easily regenerated. Moreover, the photocatalytic activity of the monolithic catalyst remained unchanged after four catalytic cycles and the morphology was still intact.
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JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
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2019
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IF 2.752
Dong Chen,Yanting Lu,Jiaojiao Wu,Nan Li,Yan-Zhen Zheng,Xia Tao
In this study, a self-powered photoelectrocatalytic (PEC) device was designed using multi-walled carbon nanotubes (CNTs) and methylamine (CH 3 NH 2 ) modified perovskite solar cells (PSCs) as the power source and CNT/TiO 2 as the photoanodes . In the PSCs, CNTs and CH 3 NH 2 were used to modify the interface between the perovskite and carbon electrode to improve the photoelectronic performance. In particular, CH 3 NH 2 induced surface-healing of the CH 3 NH 3 PbI 3 perovskite thin films and the CNTs acted as a charge transport pathway among individual perovskite nanoparticles to facilitate the collection of photogenerated holes by the carbon electrode. A power conversion efficiency of 10.39% was achieved after modification with the CNTs and CH 3 NH 2 . In the photoanodes, the CNT-modified TiO 2 electrode accelerated the electron–hole separation and transportation, thereby improving the degradation performance. After assembling the PSCs modified using CNT and CH 3 NH 2 with CNT/TiO 2 , the solar-driven PEC system exhibited a high PEC degradation rate with rhodamine B (RhB). The optimal degradation efficiency for RhB with the tandem device was close to 100% after 80 min. This low-cost tandem assembly has promising applications in pollutant degradation research.
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高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2019
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IF 3.131
Meng Wu,Luting Yan,Mingyuan Xu,Yanyun Zhu,Yuting Li,Xiaotong Sun,Runxiang Xu,Jingfa Yang
Graphene-based hydrogels (GH) have exhibited prominent performances in wastewater treatment . Herein, Special-shaped ZnO tetrapods and TiO 2 nanosheets were introduced to the preparation of GH via a one-step hydrothermal reduction method. The ZnO-GH and TiO 2 -GH composite hydrogel with a uniform 3D network structure and good mechanical properties can be used as an adsorbent for printing and dyeing wastewater. The optimum doping amount of ZnO and TiO 2 in the composite hydrogel and the adsorption regularity to rhodamine B (RhB) with different concentrations were discussed. The cyclic adsorption performance and adsorption kinetics were briefly discussed. When the doping ratio of ZnO to graphene oxide (GO) is 5:8, ZnO-GH has the best adsorption rate, which is 71.7%. The best degradation rate appears at a ZnO doping ratio of 1:2, which also shows the best total removal rate of RhB of approximately 82.20%. When the doping ratio of TiO 2 to GO is 3:4, the photocatalytic degradation rate is 30.3%, and the total removal rate of RhB reaches 99.1%, which indicates that RhB can be almost completely removed by TiO 2 -GH through adsorption and degradation. After five cycles, the adsorption capacity of ZnO-GH and TiO 2 -GH for the low RhB concentration is still good. The addition of ZnO and TiO 2 improves not only the adsorption and degradation properties of the composite hydrogel but also its recycling performance as a result of the increase in mechanical stability.
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高影响因子
CHEMICAL PHYSICS LETTERS
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2019
·
IF 1.901
Hongwei Feng,Hui Xu,Hongtu Feng,Ying Gao,Xinyuan Jin
The sol-gel method was used to synthesize Gd-SiO 2 -TiO 2 composite photocatalysts. When the doping amounts of Si and Gd reached 9.1 mol% and 0.2 mol% respectively, the sample showed the optimal photocatalytic activity during the methylene blue (MB) degradation. When the calcination temperature was lower than 550 °C, Gd-SiO 2 -TiO 2 photocatalyst has an anatase crystal structure. After doping of Si and Gd, the absorption wavelength thresholds of the sample approached 407 nm with the energy gap of 3.05 eV. Gd-SiO 2 -TiO 2 photocatalyst showed the degradation efficiency about 90% to methylene blue (MB) under irradiation of simulated sunlight.
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高影响因子
RSC Advances
·
2017
·Vol. 7
·期 78
·49446-49454
·
IF 3.108
Pan Yue,Zhi-Xian Wei,Xu-Hong Wu,He-Dan Zhang,Fan Ye
In order to identify a high-efficiency solar-light-driven magnetic photocatalyst, a series of powders such as perovskite La0.7Sr0.3MnO3, yeast-assisted La0.7Sr0.3MnO3 (Y-La0.7Sr0.3MnO3), Y-La0.7Sr0.3MnO3/TiO2 and TiO2 were prepared and characterized by photoluminescence spectroscopy (PL), UV-Vis diffuse reflectance spectroscopy (DRS), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and N2 adsorption–desorption (N2-BET). The magnetic and photocatalytic properties of the powders were also investigated. The experimental results show that, when the content of TiO2 in the composite Y-La0.7Sr0.3MnO3/TiO2 is 3.51 wt%, the Y-La0.7Sr0.3MnO3/TiO2 exhibits stronger absorption in the UV-Vis light region. A composite p–n heterojunction was formed and had the lowest photoluminescence (PL) intensity, indicating a higher separation efficiency of photogenerated charge carriers and an enhancement of the photocatalytic activity of the Y-La0.7Sr0.3MnO3/TiO2 composite. Under solar irradiation, Y-La0.7Sr0.3MnO3/TiO2 shows an obvious synergistic photocatalytic effect on orange (MO) wastewater, and the synergetic index is calculated to be 1.79. Furthermore, it still exhibits high photocatalytic activity after being reused 8 times. Moreover, Y-La0.7Sr0.3MnO3/TiO2 displays soft ferromagnetic behavior, has much higher magnetization and lower coercivity and remanence. Therefore, Y-La0.7Sr0.3MnO3/TiO2 can be recycled by an external magnetic field more easily and can be used repeatedly. Radical trapping experiments confirmed that the main reactive oxygen species (ROS) involved in the process of the photocatalytic reaction are the superoxide radical anion (˙O2−), hole (h+), and hydroxyl radical (˙OH), and the sequence of the contributions of the ROS to the photocatalytic activity of the composite is ˙O2− > h+ > ˙OH. Furthermore, the photocatalytic mechanism of Y-La0.7Sr0.3MnO3/TiO2 is proposed in this work.
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高影响因子
JOURNAL OF MATERIALS SCIENCE
·
2017
·Vol. 53
·期 4
·2638-2647
·
IF 2.599
Xu Fang,Zhang Huaiwu,Jin Lichuan,Li Yuanxun,Li Jie,Gan Gongwen,Wei Miaoqin,Li Mingming,Liao Yulong
Transient electronic is an emerging field that designed electronic devices can be fleetly and partially (or completely) degraded when transiency is triggered. Here, a class of PVA-based degradable composite film was synthesized, whose physical properties allow it to be used as substrate material for transient electronic devices. We found the dielectric properties and dissolution rate of the composite film can be tuned by controlling the TiO 2 nanoparticle addition. Based on the as-synthesized PVA/TiO 2 composite film, patch antennas were further designed and fabricated. The antennas were found to possess excellent radiation performances at a frequency of 2.5 GHz. Most importantly, the antennas could be physically degraded within 1 h when immersed in pure water. This study shows that the PVA-based film is a good candidate substrate or supporting material for transient electronics. In addition, the design and manufacture methods reported here provide a reference for other transient devices with complex structure and function.
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高影响因子
MOLECULES
·
2017
·Vol. 22
·期 11
·1943
·
IF 2.861
Xiaojia Li,Mingming Zou,Yang Wang
Highly crystalline mesoporous anatase TiO2nanospheres with high surface area (higher than P25 and anatase TiO2) are prepared by a soft-template method. Despite the high specific surface area, these samples have three times lower equilibrium adsorption (<2%) than Degussa P25. The rate constant of the mesoporous anatase TiO2(0.024 min−1) reported here is 364% higher than that of P25 (0.0066 min−1), for the same catalytic loading. The results of oxidation-extraction photometry using several reactive oxygen species (ROS) scavengers indicated that mesoporous anatase TiO2generates more ROS than P25 under UV-light irradiation. This significant improvement in the photocatalytic performance of mesoporous spherical TiO2arises from the following synergistic effects in the reported sample: (i) high surface area; (ii) improved crystallinity; (iii) narrow pore wall thicknesses (ensuring the rapid migration of photogenerated carriers to the surface of the material); and (iv) greater ROS generation under UV-light.Keywords:mesoporous anatase TiO2;high surface area;photocatalytic
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高影响因子
ChemistrySelect
·
2022
·Vol. 7
·期 40
·e202203024
·
IF 2.307
Xuehui You,Fang Liu,Guofei Jiang,Shuhua Chen,Beiya An,Rongli Cui
Graphical Degradation experiments of TC suggested that SCN/NT-2@PTFE composites showed the best photocatalytic performance under the optimal conditions, the degradation rate of tetracycline reached 99 % after 120 min of irradiation. The preparation of SCN/NT-2@PTFE composite membrane can solve the problem of difficult recovery and secondary contamination of powder catalysts. Herein we synthesized S-g-C 3 N 4 and N−TiO 2 catalysts by hydrothermal and calcination technologies and SCN/NT@PTFE membrane by a vacuum filtration method. The morphology and composition of the synthesized materials were analyzed by different characterization methods (SEM/HRTEM/XRD/XPS/UV-vis et.). The effects of different catalysts, pollutant concentrations, mass of catalyst and pH on the photo-degradation of tetracycline were investigated. The degradation rate of tetracycline by SCN/NT-2@PTFE membrane was as high as 99.9 % after 2 h of illumination. This was mainly because heterogeneous structure between S-g-C 3 N 4 and N−TiO 2 broadened the light absorption range and suppressed the carrier complex. Superoxide radicals (⋅O 2 − ) were proved to play a dominant role in the degradation reaction. After 20 days of stirring in water, the photocatalytic performance of membrane decreased slightly, demonstrating its good stability. The study of SCN/NT-2@PTFE membrane provides a new direction for the development of photocatalysis and membrane.
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