具有多谱带完美吸收效应的超构材料在光学滤波和折射率传感等多种应用中是理想的材料。提出了一种由银金属上的氮化硅介电纳米空腔阵列组成的多谱带窄带完美吸收超构材料。有限元仿真给出了四个最高可达99.9%的吸收峰,以及最小达到0.74...具有多谱带完美吸收效应的超构材料在光学滤波和折射率传感等多种应用中是理想的材料。提出了一种由银金属上的氮化硅介电纳米空腔阵列组成的多谱带窄带完美吸收超构材料。有限元仿真给出了四个最高可达99.9%的吸收峰,以及最小达到0.74 nm的吸收峰宽。这些吸收谱带来自于表面晶格模式和三个表面等离激元极化子模式。此外,这些模式的谱峰对超构材料几何外形和环境介质光学参数的变化敏感,从而在可见光-近红外范围内可以被调控。用于折射率传感时,其具有347 nm每折射率单位的灵敏度,Figure of Merit达到469。这些特性令这一材料适用于光学滤波器和折射率传感器等用途。展开更多
A combined system of Raman spectroscopy and STM has been set up, which enables the two techniques to in-situ study electrochemical interfaces simultaneously, An optical fiber head carrying one excitation fiber and fiv...A combined system of Raman spectroscopy and STM has been set up, which enables the two techniques to in-situ study electrochemical interfaces simultaneously, An optical fiber head carrying one excitation fiber and five collection fibers can be adjusted to approach to an advanced originally designed STM unit so that the STM tip above the sample electrode are surrounded by the sir fibers. The strong thermal interface by the laser illumination was avoided with the short acquisition time for SERS measurements by using optical multichannel analyzer. In-situ SERS spectrum of SCN- adsorbed on Ag electrode surface has been simultaneously recorded during STM imaging. The STM imaging taken before, during and after the SERS measurements have drifted from each other within 5%, which shows that the combined system is of satisfied over all stability.展开更多
Metallic titanium was electrochemically dissoluted in absolute ethanol in the presence of Et4N· Br(as electro conductive additive),The electrolyte solution was then directly hydrolysized to obtain nanocrystalline...Metallic titanium was electrochemically dissoluted in absolute ethanol in the presence of Et4N· Br(as electro conductive additive),The electrolyte solution was then directly hydrolysized to obtain nanocrystalline TiO2.The powder obtained was calcined at 720℃ for 1 h.FT IR,Raman spectra,XRD and TEM were used to investigate the structure and particle size of the powder.Studies showed that the nanocrystalline TiO2 prepared by this method was of monocline structure with high textural stability and narrow size distribution of 10－ 20 nm,and its Raman spectra showed a shift of about 25 cm－ 1.The experiments also showed that the product yield could be improved by controlling the temperature under 50－ 60℃ ,selecting R4N· Br as conductive additive and preventing titanium anode from being passivated.The electrochemical dissolution of metal anode may be recommanded as a promising technique for the synthesis of nanomaterials.展开更多
文摘具有多谱带完美吸收效应的超构材料在光学滤波和折射率传感等多种应用中是理想的材料。提出了一种由银金属上的氮化硅介电纳米空腔阵列组成的多谱带窄带完美吸收超构材料。有限元仿真给出了四个最高可达99.9%的吸收峰,以及最小达到0.74 nm的吸收峰宽。这些吸收谱带来自于表面晶格模式和三个表面等离激元极化子模式。此外,这些模式的谱峰对超构材料几何外形和环境介质光学参数的变化敏感,从而在可见光-近红外范围内可以被调控。用于折射率传感时,其具有347 nm每折射率单位的灵敏度,Figure of Merit达到469。这些特性令这一材料适用于光学滤波器和折射率传感器等用途。
基金supported by the National Natu-ral Science Foundation of China(No.22002129,No.21972119,No.21991151,No.22202162,No.22102137,No.22072123)the China Post-doctoral Science Foundation(No.2019TQ0177,No.2022T150548,No.2022M722648).
文摘A combined system of Raman spectroscopy and STM has been set up, which enables the two techniques to in-situ study electrochemical interfaces simultaneously, An optical fiber head carrying one excitation fiber and five collection fibers can be adjusted to approach to an advanced originally designed STM unit so that the STM tip above the sample electrode are surrounded by the sir fibers. The strong thermal interface by the laser illumination was avoided with the short acquisition time for SERS measurements by using optical multichannel analyzer. In-situ SERS spectrum of SCN- adsorbed on Ag electrode surface has been simultaneously recorded during STM imaging. The STM imaging taken before, during and after the SERS measurements have drifted from each other within 5%, which shows that the combined system is of satisfied over all stability.
文摘Metallic titanium was electrochemically dissoluted in absolute ethanol in the presence of Et4N· Br(as electro conductive additive),The electrolyte solution was then directly hydrolysized to obtain nanocrystalline TiO2.The powder obtained was calcined at 720℃ for 1 h.FT IR,Raman spectra,XRD and TEM were used to investigate the structure and particle size of the powder.Studies showed that the nanocrystalline TiO2 prepared by this method was of monocline structure with high textural stability and narrow size distribution of 10－ 20 nm,and its Raman spectra showed a shift of about 25 cm－ 1.The experiments also showed that the product yield could be improved by controlling the temperature under 50－ 60℃ ,selecting R4N· Br as conductive additive and preventing titanium anode from being passivated.The electrochemical dissolution of metal anode may be recommanded as a promising technique for the synthesis of nanomaterials.
