We report on the current-voltage (I-V) and capacitance-voltage (C-V) characteristics of the Pd/Ti/n-InP Schottky barrier diodes (SBDs) in the temperature range 160-400 K in steps of 40 K. The barrier heights and ideal...We report on the current-voltage (I-V) and capacitance-voltage (C-V) characteristics of the Pd/Ti/n-InP Schottky barrier diodes (SBDs) in the temperature range 160-400 K in steps of 40 K. The barrier heights and ideality factors of Schottky contact are found in the range 0.35 eV (I-V), 0.73 eV (C-V) at 160 K and 0.63 eV (I-V), 0.61 eV (C-V) at 400 K, respectively. It is observed that the zero-bias barrier height decreases and ideality factor n increase with a decrease in temperature, this behaviour is attributed to barrier inhomogeneities by assuming Gaussian distribution at the interface. The calculated value of series resistance (Rs) from the forward I-V characteristics is decreased with an increase in temperature. The homogeneous barrier height value of approximately 0.71 eV for the Pd/Ti Schottky diode has been obtained from the linear relationship between the temperature-dependent experimentally effective barrier heights and ideality factors. The zero-bias barrier height ( ) versus 1/2kT plot has been drawn to obtain evidence of a Gaussian distribution of the barrier heights and values of = 0.80 eV and = 114 mV for the mean barrier height and standard deviation have been obtained from the plot, respectively. The modified Richardson ln(I0/T2)- ( ) versus 1000/T plot has a good linearity over the investigated temperature range and gives the mean barrier height ( ) and Richardson constant (A*) values as 0.796 eV and 6.16 Acm-2K-2 respectively. The discrepancy between Schottky barrier heights obtained from I-V and C-V measurements is also interpreted.展开更多
In this study, palladium-loaded titania nano- tubes was fabricated on a titanium plate （Pd/TiO2NTs/Ti） for efficient electrodechlorination of 2,4-chlorophenol with a mild pH condition. The nature of PdYTiO2NTs/Ti el...In this study, palladium-loaded titania nano- tubes was fabricated on a titanium plate （Pd/TiO2NTs/Ti） for efficient electrodechlorination of 2,4-chlorophenol with a mild pH condition. The nature of PdYTiO2NTs/Ti electrodes was characterized by field-emission scanning electron microscope （FESEM）, X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS）, and cyclic voltammetry （CV） techniques. The characterization results indicated the generation of Pd~ nanoparticles which were evenly dispersed on titania nanotubes arrays on the Pd/ TiO2NTs/Ti surface. An effective degradation efficiency of up to 91% was achieved within 60 min at cathode potential of -0.7 V （vs. SCE） and initial pH of 5.5. The effects of the applied cathode potential and initial pH on the degradation efficiency were studied. A near neutral condition was more favorable since very low and very high pHs were not conducive to the dechlorination process. Furthermore, the intermediates analysis showed that the Pd/TiO2NTs/Ti electrode could completely remove chlor- ine from 2, 4-dichlorophenol since only phenol was detected as the byproduct and the concentration of released chlorine ions indicated near-complete dechlorination. This work presents a good alternative technique for eliminating persistent chlorophenols in polluted wastewater without maintaining strong acidic environment.展开更多
Ti-Zr-Ni基二十面体准晶是一类特殊的储氢材料,在氢能和核聚变能领域具有较强应用前景。采用XRD、TEM、XPS技术和气固反应系统研究了Ti39Zr38Ni17Pd6二十面体准晶的储氘性能。该合金室温下的饱和吸氘浓度接近11 mmol·D2/g·M(D...Ti-Zr-Ni基二十面体准晶是一类特殊的储氢材料,在氢能和核聚变能领域具有较强应用前景。采用XRD、TEM、XPS技术和气固反应系统研究了Ti39Zr38Ni17Pd6二十面体准晶的储氘性能。该合金室温下的饱和吸氘浓度接近11 mmol·D2/g·M(D2指氘分子,M指金属),超过Zr2Fe和Zr Co 2种合金。在吸放氘循环过程中,没有发现该合金发生相转变。饱和吸氘使得准晶格膨胀了6.37%,并使得Ti与Zr的结合能上升0.2和0.6 e V,反映出氢原子在这种材料中的占位更靠近这2种金属原子。放氘结果显示该合金具有可能较低的坪台压力,350℃左右低于1 k Pa,这意味着氘原子在该合金中比在Zr Co合金中具有更高的稳定性。以上结果表明,这种准晶有可能替代Zr2Fe和Zr Co合金而在核聚变能领域得到应用。展开更多
文摘We report on the current-voltage (I-V) and capacitance-voltage (C-V) characteristics of the Pd/Ti/n-InP Schottky barrier diodes (SBDs) in the temperature range 160-400 K in steps of 40 K. The barrier heights and ideality factors of Schottky contact are found in the range 0.35 eV (I-V), 0.73 eV (C-V) at 160 K and 0.63 eV (I-V), 0.61 eV (C-V) at 400 K, respectively. It is observed that the zero-bias barrier height decreases and ideality factor n increase with a decrease in temperature, this behaviour is attributed to barrier inhomogeneities by assuming Gaussian distribution at the interface. The calculated value of series resistance (Rs) from the forward I-V characteristics is decreased with an increase in temperature. The homogeneous barrier height value of approximately 0.71 eV for the Pd/Ti Schottky diode has been obtained from the linear relationship between the temperature-dependent experimentally effective barrier heights and ideality factors. The zero-bias barrier height ( ) versus 1/2kT plot has been drawn to obtain evidence of a Gaussian distribution of the barrier heights and values of = 0.80 eV and = 114 mV for the mean barrier height and standard deviation have been obtained from the plot, respectively. The modified Richardson ln(I0/T2)- ( ) versus 1000/T plot has a good linearity over the investigated temperature range and gives the mean barrier height ( ) and Richardson constant (A*) values as 0.796 eV and 6.16 Acm-2K-2 respectively. The discrepancy between Schottky barrier heights obtained from I-V and C-V measurements is also interpreted.
文摘In this study, palladium-loaded titania nano- tubes was fabricated on a titanium plate （Pd/TiO2NTs/Ti） for efficient electrodechlorination of 2,4-chlorophenol with a mild pH condition. The nature of PdYTiO2NTs/Ti electrodes was characterized by field-emission scanning electron microscope （FESEM）, X-ray diffraction （XRD）, X-ray photoelectron spectroscopy （XPS）, and cyclic voltammetry （CV） techniques. The characterization results indicated the generation of Pd~ nanoparticles which were evenly dispersed on titania nanotubes arrays on the Pd/ TiO2NTs/Ti surface. An effective degradation efficiency of up to 91% was achieved within 60 min at cathode potential of -0.7 V （vs. SCE） and initial pH of 5.5. The effects of the applied cathode potential and initial pH on the degradation efficiency were studied. A near neutral condition was more favorable since very low and very high pHs were not conducive to the dechlorination process. Furthermore, the intermediates analysis showed that the Pd/TiO2NTs/Ti electrode could completely remove chlor- ine from 2, 4-dichlorophenol since only phenol was detected as the byproduct and the concentration of released chlorine ions indicated near-complete dechlorination. This work presents a good alternative technique for eliminating persistent chlorophenols in polluted wastewater without maintaining strong acidic environment.
基金Foundation of Science and Technology on Surface Physics and Chemistry LaboratoryScience and Technology Development Foundation of China Academy of Engineering Physics(2013B0302046)
文摘Ti-Zr-Ni基二十面体准晶是一类特殊的储氢材料,在氢能和核聚变能领域具有较强应用前景。采用XRD、TEM、XPS技术和气固反应系统研究了Ti39Zr38Ni17Pd6二十面体准晶的储氘性能。该合金室温下的饱和吸氘浓度接近11 mmol·D2/g·M(D2指氘分子,M指金属),超过Zr2Fe和Zr Co 2种合金。在吸放氘循环过程中,没有发现该合金发生相转变。饱和吸氘使得准晶格膨胀了6.37%,并使得Ti与Zr的结合能上升0.2和0.6 e V,反映出氢原子在这种材料中的占位更靠近这2种金属原子。放氘结果显示该合金具有可能较低的坪台压力,350℃左右低于1 k Pa,这意味着氘原子在该合金中比在Zr Co合金中具有更高的稳定性。以上结果表明,这种准晶有可能替代Zr2Fe和Zr Co合金而在核聚变能领域得到应用。
