Nitrogen and phosphorus co-doped graphene quantum dot-modified Bi5O7 I(NPG/Bi5O7 I)nanorods were fabricated via a simple solvothermal method.The morphology,structure,and optical properties of the as-prepared samples w...Nitrogen and phosphorus co-doped graphene quantum dot-modified Bi5O7 I(NPG/Bi5O7 I)nanorods were fabricated via a simple solvothermal method.The morphology,structure,and optical properties of the as-prepared samples were investigated by X-ray diffraction,scanning electron microscopy,high-resolution transmission electron microscopy,X-ray photoelectron spectroscopy(XPS),and diffused reflectance spectroscopy.The photocatalytic performance was estimated by degrading the broad-spectrum antibiotics tetracycline and enrofloxacin under visible light irradiation.The photodegradation activity of Bi5O7 I improved after its surface was modified with NPGs,which was attributed to an increase in the photogenerated charge transport rate and a decrease in the electron-hole pair recombination efficiency.From the electron spin resonance spectra,XPS valence band data,and free radical trapping experiment results,the main active substances involved in the photocatalytic degradation process were determined to be photogenerated holes and superoxide radicals.A possible photocatalytic degradation mechanism for NPG/Bi5O7 I nanorods was proposed.展开更多
Band structure and component content are the key factors for determining the activity of semiconductor heterojunction. In this study, a novel Bi5O7I/BiOBrxI1-x heterostructure was synthesized by a simple hydrobromic ...Band structure and component content are the key factors for determining the activity of semiconductor heterojunction. In this study, a novel Bi5O7I/BiOBrxI1-x heterostructure was synthesized by a simple hydrobromic （HBr） acid etching method through transforming partial of Bi5O7I to I ion doped BiOBr （BiOBrxI1-x） at room temperature without adding extra dopant. Both the band structure and component content of Bi5O7I/BiOBrxI1-x alter with the additive HBr acid. The Bi5O7I/BiOBrxI1-x （S3.0） sample exhibits the best photocatalytic activity, 6 times higher than that of pure Bis071, for the degradation of methyl orange under visible-light （2 〉 420 nm）. The activity enhancement of Bi5O7I/BiOBrxI1-x is primarily ascribed to the improved separation efficiency of photocharges, originated from the adjustable band structure and component content, The significant findings of this paper provide a facile way to construct highly efficient semiconductor heterojunction via playing the synergetic effect of adjustable band struc- ture and component content for purifying organic pollutants in wastewater.展开更多
The New Niobate Ba5NdTi3Nb7O30 was synthesized by solid state reaction at 1250℃ for 48h. The crystal structure and dielectric properties of Ba5NdTi3Nb7O30 were determined by X ray powder diffraction and dielectric me...The New Niobate Ba5NdTi3Nb7O30 was synthesized by solid state reaction at 1250℃ for 48h. The crystal structure and dielectric properties of Ba5NdTi3Nb7O30 were determined by X ray powder diffraction and dielectric measurements. The results show that Ba5NdTi3Nb7O30 belongs to ferroelectric phase of tetragonal tungsten bronze structure at room temperature with unit cell parameters: a=1.24424(4)nm, c=0.39476(2)nm, calculated density 5.719g·cm-3. Ba5NdTi3Nb7O30 belongs to relaxor ferroelectrics. The phase transition temperature (Tc) of Ba5NdTi3Nb7O30 from ferroelectric to paraelectric is found to shift toward higher temperature side at higher frequency, and Tc is 90℃ at 1kHz. At room temperature, the dielectric constant (εr) and dielectric loss of Ba5NdTi3Nb7O30 decrease with the increase of frequency, and Ba5NdTi3Nb7O30 ceramic have high dielectric constant 489 at 1kHz.展开更多
文摘Nitrogen and phosphorus co-doped graphene quantum dot-modified Bi5O7 I(NPG/Bi5O7 I)nanorods were fabricated via a simple solvothermal method.The morphology,structure,and optical properties of the as-prepared samples were investigated by X-ray diffraction,scanning electron microscopy,high-resolution transmission electron microscopy,X-ray photoelectron spectroscopy(XPS),and diffused reflectance spectroscopy.The photocatalytic performance was estimated by degrading the broad-spectrum antibiotics tetracycline and enrofloxacin under visible light irradiation.The photodegradation activity of Bi5O7 I improved after its surface was modified with NPGs,which was attributed to an increase in the photogenerated charge transport rate and a decrease in the electron-hole pair recombination efficiency.From the electron spin resonance spectra,XPS valence band data,and free radical trapping experiment results,the main active substances involved in the photocatalytic degradation process were determined to be photogenerated holes and superoxide radicals.A possible photocatalytic degradation mechanism for NPG/Bi5O7 I nanorods was proposed.
基金supported by the National Natural Science Foundation of China(51772118,51472005)State Key Laboratory of Structural Chemistry(20160014)+2 种基金Anhui Provincial Natural Science Foundation(1708085MB32)the Natural Science Foundation of Educational Committee of Anhui Province(gxyq ZD2016414,KJ2014B08)Innovation Team of Design and Application of Advanced Energetic Materials
文摘Band structure and component content are the key factors for determining the activity of semiconductor heterojunction. In this study, a novel Bi5O7I/BiOBrxI1-x heterostructure was synthesized by a simple hydrobromic （HBr） acid etching method through transforming partial of Bi5O7I to I ion doped BiOBr （BiOBrxI1-x） at room temperature without adding extra dopant. Both the band structure and component content of Bi5O7I/BiOBrxI1-x alter with the additive HBr acid. The Bi5O7I/BiOBrxI1-x （S3.0） sample exhibits the best photocatalytic activity, 6 times higher than that of pure Bis071, for the degradation of methyl orange under visible-light （2 〉 420 nm）. The activity enhancement of Bi5O7I/BiOBrxI1-x is primarily ascribed to the improved separation efficiency of photocharges, originated from the adjustable band structure and component content, The significant findings of this paper provide a facile way to construct highly efficient semiconductor heterojunction via playing the synergetic effect of adjustable band struc- ture and component content for purifying organic pollutants in wastewater.
文摘The New Niobate Ba5NdTi3Nb7O30 was synthesized by solid state reaction at 1250℃ for 48h. The crystal structure and dielectric properties of Ba5NdTi3Nb7O30 were determined by X ray powder diffraction and dielectric measurements. The results show that Ba5NdTi3Nb7O30 belongs to ferroelectric phase of tetragonal tungsten bronze structure at room temperature with unit cell parameters: a=1.24424(4)nm, c=0.39476(2)nm, calculated density 5.719g·cm-3. Ba5NdTi3Nb7O30 belongs to relaxor ferroelectrics. The phase transition temperature (Tc) of Ba5NdTi3Nb7O30 from ferroelectric to paraelectric is found to shift toward higher temperature side at higher frequency, and Tc is 90℃ at 1kHz. At room temperature, the dielectric constant (εr) and dielectric loss of Ba5NdTi3Nb7O30 decrease with the increase of frequency, and Ba5NdTi3Nb7O30 ceramic have high dielectric constant 489 at 1kHz.
