Pt(100)电极上乙二醇吸附和氧化的原位时间分辨FTIRS研究

运用原位时间分辨FTIR反射光谱在分子水平研究乙二醇(EG)在Pt(100)单晶电极上吸附和氧化的动力学过程.在0.10V的时间分辨光谱中,当t>5s于2050cm?1附近出现的红外谱峰归因于EG解离吸附产物线性吸附态CO(COL)的红外吸收.红外光谱特征及其变化还证实,吸附态CO在Pt(100)表面呈均匀分布;当t>70s于2342cm?1附近出现CO2的不对称伸缩振动谱峰,指认为EG的直接氧化.研究发现随着电位升高,直接氧化逐渐成为主要反应途径,使解离吸附反应削弱.当电位高于0.40V以后,EG的氧化主要通过活性中间产物(–COOH)的途径进行

Rare Earth Eu Doped PtRu/C Catalysts and Their Properties for Methanol Electrooxidation

Corresponding authors. Email: [email protected], [email protected]; Tel: +86-773-5846279, +86-592-2180181.[中文文摘]采用化学还原和热处理方法对商业PtRu/C催化剂进行稀土Eu掺杂,制备了不同Eu含量的PtRuEux/C催化剂.透射电子显微镜(TEM)、X射线能量色散光谱(EDX)、X射线衍射(XRD)和X射线光电子能谱(XPS)等方法表征催化剂的结果表明,Eu的掺杂未改变PtRu/C催化剂的平均粒径(约为3nm),并且Eu以金属和氧化物两种形态修饰PtRu表面.循环伏安和计时电流法测试显示,PtRuEux/C催化剂较商业PtRu/C对甲醇氧化具有更高的活性,其中PtRuEu0.3/C的活性最高.运用原位傅里叶变换红外(FTIR)光谱从分子水平研究了该催化剂对甲醇电催化氧化的反应过程,检测到甲醇在催化剂上解离吸附的吸附态产物是线型吸附态CO(COL),Eu的掺杂使COL的氧化电位降低,明显提高了催化剂的活性和抗CO毒化的能力.[英文文摘]Commercially available PtRu/C catalyst was doped with Eu by chemical reduction and sintering, resulting in PtRuEux/C catalysts with different Eu contents. The catalysts were characterized by transmission electron microscopy (TEM), energy dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). Results showed that Eu doping did not change the average size of the PtRu/C catalysts (ca 3 nm), and their surfaces were modified by both Eu metal and oxide. Cyclic voltammetry and chronoamperometry demonstrated that the activity of the PtRuEux/C catalysts was higher than that of commercial PtRu/C for methanol electrooxidation. Among the PtRuEux/C catalysts, PtRuEu0.3/C exhibited the best performance. The electrocatalytic oxidation of methanol on the catalyst was further investigated by in situ Fourier transform infrared (FTIR) spectroscopy at molecular level. Results indicated that the adsorbed species derived from the dissociative adsorption of methanol on the catalysts were linear-bonded CO (COL). Eu doping decreased the oxidation potential of COL and thus significantly enhanced the activity of the catalysts and their tolerance to CO.国家自然科学基金(20833005,20828005);教育部留学回国人员科研启动基金; 厦门大学固体表面物理化学国家重点实验室开放课题;广西研究生教育创新计划项

InGaN光致发光性质与温度的关系

分析了用金属有机物气相外延方法(MOVPE)在蓝宝石衬底上生长的铟镓氮(InGaN)的光致发光(PL)性质。发现在4.7K至300K范围内，随着温度升高，InGaN带边辐射向低能方向移动，峰值变化基本符合Varshni经验公式；同时InGaN发光强度虽有所衰减，但比GaN衰减程度小，分析了导致GaN和InGaN光致发光减弱的可能因素

高提取效率氮化镓发光二极管的制作方法

一种高提取效率氮化镓发光二极管的制作方法，包括：步骤1：在衬底上制备氮化镓外延片；步骤2：在氮化镓外延片上制备第一层掩膜和第二层掩膜；步骤3：采用不同图形面积光刻版进行光刻，将第二层掩膜的两侧刻蚀掉，使第二层掩膜的面积小于第一层掩膜的面积；步骤4：通过双层掩膜的差异，采用ICP刻蚀的方法，将第一层掩膜和氮化镓外延片两侧刻蚀成梯形台面，该梯形台面的上部的宽度与第二层掩膜的宽度相同，该梯形台面的下部的宽度与衬底的宽度相同；步骤5：采用湿法腐蚀的方法，腐蚀掉第一层掩膜和第二层掩膜；步骤6：在氮化镓外延片上制作P电极；步骤7：采用激光剥离的方法，去掉衬底；步骤8：在P电极上制作转移衬底；步骤9：在氮化镓外延片上制作N电极，完成制备

GaAs/AIGaAs光子平行存贮器的性能

报告用PnpN型GaAs/AlGaAs结构的光电双稳器件形成的光子平行存贮器单元器件和4×4阵列器件的特性。单元器件的最小维持功耗小于30μW。使器件从“关闭”态翻转到“导通”态所需的光触发功率小于80μW。单元面积160×160μm、间距40μm的存贮器4×4原理性阵列已经研制成功,这是0.85μm波长范围的光子平行存贮器的首次报道