Novel Bi_2S_3/BiOCl photocatalysts were successfully synthesized via a facile biomoleculeassisted solvothermal method and biomolecule L-cysteine was used as the sulfur source.The structures,morphology,and optical prop...Novel Bi_2S_3/BiOCl photocatalysts were successfully synthesized via a facile biomoleculeassisted solvothermal method and biomolecule L-cysteine was used as the sulfur source.The structures,morphology,and optical properties of the synthesized samples were characterized by X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),Raman spectroscopy,transmission electron microscopy(TEM),and UV-vis diffuse reflectance spectroscopy(DRS).The presence of Bi_2S_3 in the Bi_2S_3/BiOCl composites could not only improve the optical properties but also enhance the photocatalytic activities for the degradation of Rhodamine B(Rh B) under visible-light irradiation(λ>420 nm) as compared with single Bi_2S_3 and BiOCl.Especially,the sample displayed the best performance of the photodegradation when the feed molar ratio of BiCl_3 and L-cysteine was 2.4:1,which was about 10 times greater than that of pure Bi OCl.The enhanced photocatalytic activities could be ascribed to the effective separation of photoinduced electrons and holes and the photosensitization of dye.Moreover,the possible photodegradation mechanism was also proposed,and the results revealed that the active holes(h+) and superoxide radicals(·O_2^-) were the main reactive species during photocatalytic degradation.展开更多
A series of Bi2 S3-BiOCI composites with two-dimensional(2 D) square-like structures were prepared via a two-step anion exchange route.X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron m...A series of Bi2 S3-BiOCI composites with two-dimensional(2 D) square-like structures were prepared via a two-step anion exchange route.X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM), and diffuse reflectance spectra(DRS)were used to investigate the properties of the as-prepared Bi_2 S_3-BiOCI heterostructures. The coupling of BiOCl and Bi_2 S_3 induced enhanced photoabsorption efficiency and bandgap narrowing. A reactive brilliant red X-3 B dye was used as a contaminant to test the photocatalytic activity of the obtained Bi_2 S_3-BiOCl samples under visible light irradiation. The sample Bi_2 S_3-BiOCl with a mass ratio of 8:4 exhibited the highest photodegradation efficiency, which was six times higher than that of pure BiOCl. In addition, a mechanism for the enhancement of photocatalytic activity is proposed.展开更多
TiO_2 films have been widely applied in photovoltaic conversion techniques. TiO_2 nanotube arrays(TiO_2 NAs) can be grown directly on the surface of metal Ti by the anodic oxidation method. Bi_2S_3 and Pb S nanopartic...TiO_2 films have been widely applied in photovoltaic conversion techniques. TiO_2 nanotube arrays(TiO_2 NAs) can be grown directly on the surface of metal Ti by the anodic oxidation method. Bi_2S_3 and Pb S nanoparticles(NPs) were firstly co-sensitized on TiO_2NAs(denoted as PbS/Bi_2S_3(n)/TiO_2NAs) by a two-step process containing hydrothermal and sonication-assisted SILAR method.When the concentration of Bi^(3+) is 5 mmol/L, the best photoelectrical performance was obtained under simulated solar irradiation. The short-circuit photocurrent(J_(sc)) and photoconversion efficiency(η) of PbS/Bi_2S_3(5)/TiO_2 NAs electrode were 4.70 m A/cm and 1.13 %, respectively.展开更多
Due to increasingly serious environmental problems,many researchers are investigating green cleanenergy to solve the world’s energy supply issues.So the strategy that Au nanoparticles(Au NPs)and bismuth sulfide(Bi2S3...Due to increasingly serious environmental problems,many researchers are investigating green cleanenergy to solve the world’s energy supply issues.So the strategy that Au nanoparticles(Au NPs)and bismuth sulfide(Bi2S3)NPs are used to evenly decorate TiO2 nanotube arrays(TiO2 NTAs)was carried out.Composite materials demonstrated enhanced solar light absorption ability and excellent photoelectrochemical performance.This was attributed to the presence of Bi2S3 NPs with a narrow band gap and the decoration with noble metallic Au NPs which resulted in local surface plasmon resonance(LSPR)effects.The Au/Bi2S3@TiO2 NTAs composites exhibit improved photocatalytic activity for the degradation of methylene blue(MB)under irradiation of UV and visible light.Moreover,the Au/Bi2S3@TiO2 NTAs exhibits high fluorescence emission at 822 nm.Due to the better binding affinity between Bi2S3,TiO2 and Fe3+ions,the synthesized nanocomposites exhibit high selectivity to Fe3+ions.The number of binding sites for Au/Bi2S3@TiO2 NTAs was estimated to be 1.41 according to the double logarithmic regression method.The calculated value of"K"was 1862 M-1.Fluorescence emission intensity decreases with increasing concentration(30μM–5000μM).The detection limit of the synthesized sensor is 0.221μM.展开更多
Bi2S3-xSex/poly(methyl methacrylate)(PMMA)nanocomposite films were prepared using microwave assisted synthesis with different compositions of x.Crystal structure,surface morphology,and optical properties were investig...Bi2S3-xSex/poly(methyl methacrylate)(PMMA)nanocomposite films were prepared using microwave assisted synthesis with different compositions of x.Crystal structure,surface morphology,and optical properties were investigated to characterize the prepared nanocomposite films.The crystallinity and optical band gap of the prepared Bi2S3-xSex/PMMA were affected by x.The prepared samples showed a blue shift in the absorption edge.The laser power dependent nonlinear refraction and absorption of Bi2S3-xSex/PMMA nanocomposite films were investigated by using the Z-scan technique.The optical nonlinearity of the nanocomposite films exhibited switchover from negative nonlinear refraction to positive nonlinear refraction to negative nonlinear refraction effects,and from saturable absorption to reverse saturable absorption to saturable absorption with an increase and decrease in the composition.An interesting all-optical figure of merit was reported to assess the nanocomposite films for a practical device.It was calculated that the device all-figures of merit were based on the nonlinear response,which is important for the all-optical switching device.The results demonstrate that the optimized all-optical figures of merit can be achieved by adjusting the composition and input laser power,which can be used for the design of different all-photonic devices,and the results of nonlinear switching behavior can open new possibilities for using the nanocomposite films in laser Q-switching and mode-locking.展开更多
基金Funded by the National Natural Science Foundation of China(No.51272107)the Natural Science Foundation of Jiangsu Province,China(No.BK2011024)the Specialized Research Fund for the Doctoral Program of Higher Education(No.20133219110015)
文摘Novel Bi_2S_3/BiOCl photocatalysts were successfully synthesized via a facile biomoleculeassisted solvothermal method and biomolecule L-cysteine was used as the sulfur source.The structures,morphology,and optical properties of the synthesized samples were characterized by X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),Raman spectroscopy,transmission electron microscopy(TEM),and UV-vis diffuse reflectance spectroscopy(DRS).The presence of Bi_2S_3 in the Bi_2S_3/BiOCl composites could not only improve the optical properties but also enhance the photocatalytic activities for the degradation of Rhodamine B(Rh B) under visible-light irradiation(λ>420 nm) as compared with single Bi_2S_3 and BiOCl.Especially,the sample displayed the best performance of the photodegradation when the feed molar ratio of BiCl_3 and L-cysteine was 2.4:1,which was about 10 times greater than that of pure Bi OCl.The enhanced photocatalytic activities could be ascribed to the effective separation of photoinduced electrons and holes and the photosensitization of dye.Moreover,the possible photodegradation mechanism was also proposed,and the results revealed that the active holes(h+) and superoxide radicals(·O_2^-) were the main reactive species during photocatalytic degradation.
基金supported by the Natural Science Foundation of Jiangsu Province(Grant No.BK2012464)the Research Fellowship from the Jiangsu Overseas Research and Training Programfunded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
文摘A series of Bi2 S3-BiOCI composites with two-dimensional(2 D) square-like structures were prepared via a two-step anion exchange route.X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM), and diffuse reflectance spectra(DRS)were used to investigate the properties of the as-prepared Bi_2 S_3-BiOCI heterostructures. The coupling of BiOCl and Bi_2 S_3 induced enhanced photoabsorption efficiency and bandgap narrowing. A reactive brilliant red X-3 B dye was used as a contaminant to test the photocatalytic activity of the obtained Bi_2 S_3-BiOCl samples under visible light irradiation. The sample Bi_2 S_3-BiOCl with a mass ratio of 8:4 exhibited the highest photodegradation efficiency, which was six times higher than that of pure BiOCl. In addition, a mechanism for the enhancement of photocatalytic activity is proposed.
基金supported by Program of International S&T Cooperation(2013 DFA51050)National Magnetic Confinement Fusion Science Program(2013GB110001)+2 种基金the 863Program(2014AA032701)the National Natural Science Foundation of China(11405138,51302231)the Western Superconducting Technologies Co.,Ltd
文摘TiO_2 films have been widely applied in photovoltaic conversion techniques. TiO_2 nanotube arrays(TiO_2 NAs) can be grown directly on the surface of metal Ti by the anodic oxidation method. Bi_2S_3 and Pb S nanoparticles(NPs) were firstly co-sensitized on TiO_2NAs(denoted as PbS/Bi_2S_3(n)/TiO_2NAs) by a two-step process containing hydrothermal and sonication-assisted SILAR method.When the concentration of Bi^(3+) is 5 mmol/L, the best photoelectrical performance was obtained under simulated solar irradiation. The short-circuit photocurrent(J_(sc)) and photoconversion efficiency(η) of PbS/Bi_2S_3(5)/TiO_2 NAs electrode were 4.70 m A/cm and 1.13 %, respectively.
基金supported by the National Natural Science Foundation of China(Nos.51972063 and 21501127)the 111 Project(No.D17005)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD).
文摘Due to increasingly serious environmental problems,many researchers are investigating green cleanenergy to solve the world’s energy supply issues.So the strategy that Au nanoparticles(Au NPs)and bismuth sulfide(Bi2S3)NPs are used to evenly decorate TiO2 nanotube arrays(TiO2 NTAs)was carried out.Composite materials demonstrated enhanced solar light absorption ability and excellent photoelectrochemical performance.This was attributed to the presence of Bi2S3 NPs with a narrow band gap and the decoration with noble metallic Au NPs which resulted in local surface plasmon resonance(LSPR)effects.The Au/Bi2S3@TiO2 NTAs composites exhibit improved photocatalytic activity for the degradation of methylene blue(MB)under irradiation of UV and visible light.Moreover,the Au/Bi2S3@TiO2 NTAs exhibits high fluorescence emission at 822 nm.Due to the better binding affinity between Bi2S3,TiO2 and Fe3+ions,the synthesized nanocomposites exhibit high selectivity to Fe3+ions.The number of binding sites for Au/Bi2S3@TiO2 NTAs was estimated to be 1.41 according to the double logarithmic regression method.The calculated value of"K"was 1862 M-1.Fluorescence emission intensity decreases with increasing concentration(30μM–5000μM).The detection limit of the synthesized sensor is 0.221μM.
文摘Bi2S3-xSex/poly(methyl methacrylate)(PMMA)nanocomposite films were prepared using microwave assisted synthesis with different compositions of x.Crystal structure,surface morphology,and optical properties were investigated to characterize the prepared nanocomposite films.The crystallinity and optical band gap of the prepared Bi2S3-xSex/PMMA were affected by x.The prepared samples showed a blue shift in the absorption edge.The laser power dependent nonlinear refraction and absorption of Bi2S3-xSex/PMMA nanocomposite films were investigated by using the Z-scan technique.The optical nonlinearity of the nanocomposite films exhibited switchover from negative nonlinear refraction to positive nonlinear refraction to negative nonlinear refraction effects,and from saturable absorption to reverse saturable absorption to saturable absorption with an increase and decrease in the composition.An interesting all-optical figure of merit was reported to assess the nanocomposite films for a practical device.It was calculated that the device all-figures of merit were based on the nonlinear response,which is important for the all-optical switching device.The results demonstrate that the optimized all-optical figures of merit can be achieved by adjusting the composition and input laser power,which can be used for the design of different all-photonic devices,and the results of nonlinear switching behavior can open new possibilities for using the nanocomposite films in laser Q-switching and mode-locking.
