To further improve the charge separation and photocatalytic activities of g-C3N4 and CdMoO4 under visible light irradiation,CdMoO4/g-C3N4 composites were rationally synthesized by a facile precipitation-calcination pr...To further improve the charge separation and photocatalytic activities of g-C3N4 and CdMoO4 under visible light irradiation,CdMoO4/g-C3N4 composites were rationally synthesized by a facile precipitation-calcination procedure.The crystal phases,morphologies,chemical compositions,textural structures,and optical properties of the as-prepared composites were characterized by the corresponding analytical techniques.The photocatalytic activities toward degradation of rhodamine B solution were evaluated under visible light irradiation.The results revealed that integrating CdMoO4 with g-C3N4 could remarkably improve the charge separation and photocatalytic activity,compared with those of pristine g-C3N4 and CdMoO4.This would be because the CdMoO4/g-C3N4 composites could facilitate the transfer and separation of the photoexcited electron-hole pairs,which was confirmed by electrochemical impedance spectroscopy,transient photocurrent responses,and photoluminescence measurements.Moreover,active species trapping experiments demonstrated that holes(h+)and superoxide radicals(?O2?)were the main active species during the photocatalytic reaction.A possible photocatalytic mechanism was proposed on the basis of the energy band structures determined by Mott-Schottky tests.This work would provide further insights into the rational fabrication of composites for organic contaminant removal.展开更多
Bismuth containing nanomaterials recently received increasing attention with respect to environmental applications because of their low cost, high stability and nontoxicity. In this work, Bi–Bi_2O_2CO_3 heterojunctio...Bismuth containing nanomaterials recently received increasing attention with respect to environmental applications because of their low cost, high stability and nontoxicity. In this work, Bi–Bi_2O_2CO_3 heterojunctions were fabricated by in-situ decoration of Bi nanoparticles on Bi_2O_2CO_3 nanosheets via a simple hydrothermal synthesis approach. X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM) and high-resolution TEM(HRTEM) were used to confirm the morphology of the nanosheet-like heterostructure of the Bi–Bi_2O_2CO_3 composite. Detailed ultrafast electronic spectroscopy reveals that the in-situ decoration of Bi nanoparticles on Bi_2O_2CO_3 nanosheets exhibit a dramatically enhanced electron-hole pair separation rate, which results in an extraordinarily high photocatalytic activity for the degradation of a model organic dye, methylene blue(MB) under visible light illumination. Cycling experiments revealed a good photochemical stability of the Bi–Bi_2O_2CO_3 heterojunction under repeated irradiation. Photocurrent measurements further indicated that the heterojunction incredibly enhanced the charge generation and suppressed the charge recombination of photogenerated electron-hole pairs.展开更多
The well crystalline YAG：Ce^3＋ phosphor was synthesized by sold-state method, and the temperature dependence of excitation and emission spectra of YAG：Ce^3＋ phosphor were investigated in the temperature range from...The well crystalline YAG：Ce^3＋ phosphor was synthesized by sold-state method, and the temperature dependence of excitation and emission spectra of YAG：Ce^3＋ phosphor were investigated in the temperature range from room temperature to 573 K. With temperature increasing, it was noted that the emission intensity of as-repared phosphors decreased considerably more rapidly when pumped by 460 nm than by 340 nm. The temperature-intensity curves under different excitation wavelengths were obtained using an Arrhenius function, and the corresponding activation energies were also obtained respectively. Thus, the experimental phenomenon was discussed in terms of nonradiative decay rate. The effects of as-prepared phosphors on the performance of the white LED with changing temperature were also studied.展开更多
The Fe-based ionic liquid doped g-C_3N_4(Fee CN) photocatalyst was firstly prepared base on ultrathin g-C_3N_4 obtained by multiple calcination method with a metal-based reactive ionic liquid [Omim]FeCl_4 for the degr...The Fe-based ionic liquid doped g-C_3N_4(Fee CN) photocatalyst was firstly prepared base on ultrathin g-C_3N_4 obtained by multiple calcination method with a metal-based reactive ionic liquid [Omim]FeCl_4 for the degradation of Rhodamine B(RhB). Experimental results revealed that Fe3+species were doped into the framework of g-C_3N_4. The effect of the amount of Fe-doping on the catalytic activity was performed. The result showed that the Fee CN could effectively degrade RhB under the condition of visible light irradiation. The photocurrent analysis showed that the incorporation of Fe^(3+)into g-C_3N_4 material could accelerate the separation of the photogenerated carriers significantly.At the same time, the reactive species generated during the photodegradation process were tested by radicals trapping experiments and electron spin resonance(ESR). It was proposed that the synergistic effect of■ and ·OH contributed to degrade RhB efficiently.展开更多
Eu3+-activated Gd2(MoO4)3 pseudo-pompon-like red-emitting phosphors were prepared by solid-state method. The structure, morphology, and luminescent properties of these powder samples were investigated by X-ray diffrac...Eu3+-activated Gd2(MoO4)3 pseudo-pompon-like red-emitting phosphors were prepared by solid-state method. The structure, morphology, and luminescent properties of these powder samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and fluorescent spectrophotometry, respectively. The as-obtained phosphors were single crystalline phase with orthorhombic unit cell. The particles of the powder samples had the length of 5-12 m and width of 3-7 m with flake shape and large surface area, which is suitable for manufacture of white LEDs. The phosphor could be efficiently excited by the incident light of 348-425 nm, well matched with the output wavelength of near-UV (In,Ga)N chip, and re-emitted an intense red light peaking at 615 nm. By combing this phosphor with a ~395 nm-emitting (In,Ga)N chip, a red LED was fabricated, so that the applicability of this novel phosphor to white LEDs was confirmed. It is considered to be an efficient red-emitting conversion phosphor for solid-state lighting based on (In,Ga)N LEDs.展开更多
Cobalt-doped titania(Co-TiO2)nanomaterials were synthesized by the sol–gel method at different calcination temperatures.Using Escherichia coli(a),Staphylococcus aureus(b)and Candida albicans(c)as target strains,the a...Cobalt-doped titania(Co-TiO2)nanomaterials were synthesized by the sol–gel method at different calcination temperatures.Using Escherichia coli(a),Staphylococcus aureus(b)and Candida albicans(c)as target strains,the antibacterial activity in visible light of the nanomaterials were studied.Co-TiO2 nanomaterials were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),UV–Vis diffuse reflectance spectroscopy(DRS),Fourier transform infrared spectrum(FT-IR)and X-ray photoelectron spectroscopy(XPS).The Co ions in the Co-TiO2 nanomaterial exist in the form of CoTiO3 phase.The antibacterial properties of Co-TiO2 nanomaterials on E.coli(a),S.aureus(b)and C.albicans(c)were investigated with the oscillating flask method and the inhibition zone method.The nanomaterials calcined at 600°C exhibit excellent antibacterial activity.The bacteriostatic rates for E.coli,S.aureus and C.albicans reached 99.5%,91.3%and 93.4%respectively.The diameters of the antibacterial rings were up to 36 mm,37 mm,30 mm respectively,and the clarity of the ring was clear.The antibacterial properties of Co-TiO2 nanomaterials were compared with those of traditional silver sol,zinc oxide sol and Zn-doped TiO2 nanomaterials The mechanism of the influences of Co ions doping on the antibacterial activity of TiO2 nanomaterials was also discussed.The doping of Co ions inhibits the particle size of the antibacterial agent and extends the photocatalytic response range,thereby improving the photocatalytic performance of the antibacterial agent.展开更多
基金supported by the Open Project Program of Hubei Key Laboratory of Animal Nutrition and Feed Science,Wuhan Polytechnic University(No.201808)Hubei Important Project of Technological Innovation(2018ABA094)~~
文摘To further improve the charge separation and photocatalytic activities of g-C3N4 and CdMoO4 under visible light irradiation,CdMoO4/g-C3N4 composites were rationally synthesized by a facile precipitation-calcination procedure.The crystal phases,morphologies,chemical compositions,textural structures,and optical properties of the as-prepared composites were characterized by the corresponding analytical techniques.The photocatalytic activities toward degradation of rhodamine B solution were evaluated under visible light irradiation.The results revealed that integrating CdMoO4 with g-C3N4 could remarkably improve the charge separation and photocatalytic activity,compared with those of pristine g-C3N4 and CdMoO4.This would be because the CdMoO4/g-C3N4 composites could facilitate the transfer and separation of the photoexcited electron-hole pairs,which was confirmed by electrochemical impedance spectroscopy,transient photocurrent responses,and photoluminescence measurements.Moreover,active species trapping experiments demonstrated that holes(h+)and superoxide radicals(?O2?)were the main active species during the photocatalytic reaction.A possible photocatalytic mechanism was proposed on the basis of the energy band structures determined by Mott-Schottky tests.This work would provide further insights into the rational fabrication of composites for organic contaminant removal.
基金DST,India for financial grant(SB/S1/PC-011/2013)DAE(India)for financial grant 2013/37P/73/BRNS,NTH-School‘‘Contacts in Nanosystems:Interactions,Control and Quantum Dynamics’’+1 种基金the Braunschweig International Graduate School of Metrology(IGSM)DFG-RTG 1952/1,Metrology for Complex Nanosystems
文摘Bismuth containing nanomaterials recently received increasing attention with respect to environmental applications because of their low cost, high stability and nontoxicity. In this work, Bi–Bi_2O_2CO_3 heterojunctions were fabricated by in-situ decoration of Bi nanoparticles on Bi_2O_2CO_3 nanosheets via a simple hydrothermal synthesis approach. X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM) and high-resolution TEM(HRTEM) were used to confirm the morphology of the nanosheet-like heterostructure of the Bi–Bi_2O_2CO_3 composite. Detailed ultrafast electronic spectroscopy reveals that the in-situ decoration of Bi nanoparticles on Bi_2O_2CO_3 nanosheets exhibit a dramatically enhanced electron-hole pair separation rate, which results in an extraordinarily high photocatalytic activity for the degradation of a model organic dye, methylene blue(MB) under visible light illumination. Cycling experiments revealed a good photochemical stability of the Bi–Bi_2O_2CO_3 heterojunction under repeated irradiation. Photocurrent measurements further indicated that the heterojunction incredibly enhanced the charge generation and suppressed the charge recombination of photogenerated electron-hole pairs.
基金the Key Technologies R&D Program of Shandong Province (2006gg2201014)Tianjin Natural Science Foundation (07JCYBJC06400)Tianjin Education Committee Science and Technology Development Foundation
文摘The well crystalline YAG：Ce^3＋ phosphor was synthesized by sold-state method, and the temperature dependence of excitation and emission spectra of YAG：Ce^3＋ phosphor were investigated in the temperature range from room temperature to 573 K. With temperature increasing, it was noted that the emission intensity of as-repared phosphors decreased considerably more rapidly when pumped by 460 nm than by 340 nm. The temperature-intensity curves under different excitation wavelengths were obtained using an Arrhenius function, and the corresponding activation energies were also obtained respectively. Thus, the experimental phenomenon was discussed in terms of nonradiative decay rate. The effects of as-prepared phosphors on the performance of the white LED with changing temperature were also studied.
基金the financial support from the National Natural Science Foundation of China(No.21722604,21576122)Chinese Postdoctoral Science Foundation(No.2017M611726)
文摘The Fe-based ionic liquid doped g-C_3N_4(Fee CN) photocatalyst was firstly prepared base on ultrathin g-C_3N_4 obtained by multiple calcination method with a metal-based reactive ionic liquid [Omim]FeCl_4 for the degradation of Rhodamine B(RhB). Experimental results revealed that Fe3+species were doped into the framework of g-C_3N_4. The effect of the amount of Fe-doping on the catalytic activity was performed. The result showed that the Fee CN could effectively degrade RhB under the condition of visible light irradiation. The photocurrent analysis showed that the incorporation of Fe^(3+)into g-C_3N_4 material could accelerate the separation of the photogenerated carriers significantly.At the same time, the reactive species generated during the photodegradation process were tested by radicals trapping experiments and electron spin resonance(ESR). It was proposed that the synergistic effect of■ and ·OH contributed to degrade RhB efficiently.
基金Project supported by the Natural Science Research Project of the Jiangsu Higher Education Institutions (08KJD150014)the QingLan Project of the Jiangsu Province (2008)the Basic Research Fund of Jiangsu Teachers University of Technology (KYY09031)
文摘Eu3+-activated Gd2(MoO4)3 pseudo-pompon-like red-emitting phosphors were prepared by solid-state method. The structure, morphology, and luminescent properties of these powder samples were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and fluorescent spectrophotometry, respectively. The as-obtained phosphors were single crystalline phase with orthorhombic unit cell. The particles of the powder samples had the length of 5-12 m and width of 3-7 m with flake shape and large surface area, which is suitable for manufacture of white LEDs. The phosphor could be efficiently excited by the incident light of 348-425 nm, well matched with the output wavelength of near-UV (In,Ga)N chip, and re-emitted an intense red light peaking at 615 nm. By combing this phosphor with a ~395 nm-emitting (In,Ga)N chip, a red LED was fabricated, so that the applicability of this novel phosphor to white LEDs was confirmed. It is considered to be an efficient red-emitting conversion phosphor for solid-state lighting based on (In,Ga)N LEDs.
基金the support from the National Natural Science Foundation of China(No.51474056)。
文摘Cobalt-doped titania(Co-TiO2)nanomaterials were synthesized by the sol–gel method at different calcination temperatures.Using Escherichia coli(a),Staphylococcus aureus(b)and Candida albicans(c)as target strains,the antibacterial activity in visible light of the nanomaterials were studied.Co-TiO2 nanomaterials were characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),UV–Vis diffuse reflectance spectroscopy(DRS),Fourier transform infrared spectrum(FT-IR)and X-ray photoelectron spectroscopy(XPS).The Co ions in the Co-TiO2 nanomaterial exist in the form of CoTiO3 phase.The antibacterial properties of Co-TiO2 nanomaterials on E.coli(a),S.aureus(b)and C.albicans(c)were investigated with the oscillating flask method and the inhibition zone method.The nanomaterials calcined at 600°C exhibit excellent antibacterial activity.The bacteriostatic rates for E.coli,S.aureus and C.albicans reached 99.5%,91.3%and 93.4%respectively.The diameters of the antibacterial rings were up to 36 mm,37 mm,30 mm respectively,and the clarity of the ring was clear.The antibacterial properties of Co-TiO2 nanomaterials were compared with those of traditional silver sol,zinc oxide sol and Zn-doped TiO2 nanomaterials The mechanism of the influences of Co ions doping on the antibacterial activity of TiO2 nanomaterials was also discussed.The doping of Co ions inhibits the particle size of the antibacterial agent and extends the photocatalytic response range,thereby improving the photocatalytic performance of the antibacterial agent.
