A comprehensive study on Raman spectroscopy with different excitation wavelengths, sample sizes, and sample shapes for optic phonons （OPs） and acoustic phonons （APs） in polar and non-polar nano-semiconductors has ...A comprehensive study on Raman spectroscopy with different excitation wavelengths, sample sizes, and sample shapes for optic phonons （OPs） and acoustic phonons （APs） in polar and non-polar nano-semiconductors has been performed. The study affirms that the finite size effect does not appear in the OPs of polar nano-semiconductors, while it exists in all other types of phonons. The absence of the FSE is confirmed to originate from the long-range FrShlieh interaction and the breaking of translation symmetry. The result indicates that the Raman spectra of OPs cannot be used as a method to characterize the scale and crystalline property of polar nano-semiconductors.展开更多
Visible-light-driven photocatalysis as a green technology has attracted a lot of attention due to its potential applications in environmental remediation. Vesicle Cd Se nano-semiconductor photocatalyst are successfull...Visible-light-driven photocatalysis as a green technology has attracted a lot of attention due to its potential applications in environmental remediation. Vesicle Cd Se nano-semiconductor photocatalyst are successfully prepared by a gas template method and characterized by a variety of methods. The vesicle Cd Se nano-semiconductors display enhanced photocatalytic performance for the degradation of tetracycline hydrochloride, the photodegradation rate of78.824% was achieved by vesicle Cd Se, which exhibited an increase of 31.779% compared to granular Cd Se. Such an exceptional photocatalytic capability can be attributed to the unique structure of the vesicle Cd Se nano-semiconductor with enhanced light absorption ability and excellent carrier transport capability. Meanwhile, the large surface area of the vesicle Cd Se nano-semiconductor can increase the contact probability between catalyst and target and provide more surface-active centers. The photocatalytic mechanisms are analyzed by active species quenching. It indicates that h＋and UO2^-are the main active species which play a major role in catalyzing environmental toxic pollutants. Simultaneously, the vesicle Cd Se nano-semiconductor had high efficiency and stability.展开更多
Zeolite FSM 16 was synthesized by reconstruction of layered silicate in the presence of organic surfactant. With partial replacement of Ti 3+ with organic cations, TiO 2 nano structured particles were simultaneously b...Zeolite FSM 16 was synthesized by reconstruction of layered silicate in the presence of organic surfactant. With partial replacement of Ti 3+ with organic cations, TiO 2 nano structured particles were simultaneously built in the channel of the zeolite as the framework of the zeolite was formed. XRD, IR and Raman spectroscopic characterizations indicate that SiO 4 tetrahedron may be distorted and transferred from Q 3 to Q 2 form due to the pucker and reconstruction of the layered structure. The formation of TiO 2 nano structured particles had no influence on the formation of zeolite framework, however, the interaction obviously occurred between TiO 2 nano structured particles and zeolite framework.展开更多
基金Project supported by the National Basic Research Program of China (Grants Nos. 2009CB929403 and 2012CB825700)the National Natural Science Foundation of China (Grants Nos. 10774006 and 60876002)
文摘A comprehensive study on Raman spectroscopy with different excitation wavelengths, sample sizes, and sample shapes for optic phonons （OPs） and acoustic phonons （APs） in polar and non-polar nano-semiconductors has been performed. The study affirms that the finite size effect does not appear in the OPs of polar nano-semiconductors, while it exists in all other types of phonons. The absence of the FSE is confirmed to originate from the long-range FrShlieh interaction and the breaking of translation symmetry. The result indicates that the Raman spectra of OPs cannot be used as a method to characterize the scale and crystalline property of polar nano-semiconductors.
基金supported by the National Natural Science Foundation of China (Nos. 21546013, U1510126, 21407064)the Natural Science Foundation of Jiangsu Province (No. BK20131259)+3 种基金the China Postdoctoral Science Foundation (No. 2015 M571684)the Jiangsu Postdoctoral Science Foundation (No. 1501102B)the Innovation Programs Foundation of Jiangsu Province (No. KYLX15_1089)the Open Research Fund of State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology (No. 12KF09)
文摘Visible-light-driven photocatalysis as a green technology has attracted a lot of attention due to its potential applications in environmental remediation. Vesicle Cd Se nano-semiconductor photocatalyst are successfully prepared by a gas template method and characterized by a variety of methods. The vesicle Cd Se nano-semiconductors display enhanced photocatalytic performance for the degradation of tetracycline hydrochloride, the photodegradation rate of78.824% was achieved by vesicle Cd Se, which exhibited an increase of 31.779% compared to granular Cd Se. Such an exceptional photocatalytic capability can be attributed to the unique structure of the vesicle Cd Se nano-semiconductor with enhanced light absorption ability and excellent carrier transport capability. Meanwhile, the large surface area of the vesicle Cd Se nano-semiconductor can increase the contact probability between catalyst and target and provide more surface-active centers. The photocatalytic mechanisms are analyzed by active species quenching. It indicates that h＋and UO2^-are the main active species which play a major role in catalyzing environmental toxic pollutants. Simultaneously, the vesicle Cd Se nano-semiconductor had high efficiency and stability.
文摘Zeolite FSM 16 was synthesized by reconstruction of layered silicate in the presence of organic surfactant. With partial replacement of Ti 3+ with organic cations, TiO 2 nano structured particles were simultaneously built in the channel of the zeolite as the framework of the zeolite was formed. XRD, IR and Raman spectroscopic characterizations indicate that SiO 4 tetrahedron may be distorted and transferred from Q 3 to Q 2 form due to the pucker and reconstruction of the layered structure. The formation of TiO 2 nano structured particles had no influence on the formation of zeolite framework, however, the interaction obviously occurred between TiO 2 nano structured particles and zeolite framework.
