共查询到17条相似文献,搜索用时 125 毫秒
1.
2.
以硝酸镍、尿素为原料,在醇-水介质中,85℃恒温条件下,用均匀沉淀法制备出花状纳米片自组装结构Ni(OH)_2沉淀,该沉淀经400℃煅烧制得具有花状形貌的NiO纳米片自组装体.采用X射线衍射、扫描电镜、透射电镜、Fourier变换红外光谱、Brunauer-Ennett-Teller(BET)比表面积方法对粉体进行表征.研究表明:该NiO粉体为六方结构,其纳米片尺寸约为2μm × 3μm,厚度约为100nm,曲面间隙约为0.8μm,具有微孔结构.BET法测得粉体的比表面积为108.66m~2/g,制得的粉体具有明显的纳米效应,Ni-O键振动峰值(403.6cm~(-1))较非纳米颗粒(487.1 cm~(-1))蓝移了84.5cm~(-1),乙醇对花状结构NiO纳米片自组装体的形成具有重要作用.分析了花状NiO纳米片自组装体的形成机理. 相似文献
3.
基于KMnO4的自分解反应,采用水热法在180℃制备了氧化锰材料.应用X-射线衍射、扫描电镜和透射电镜技术对所得材料的结构和形貌进行了表征.结果表明,所得材料为具有Birnessite结构的层状氧化锰花球,花球由纳米片组装而成.电化学测试结果显示,制备材料表现出优良的电容特性.当电流密度为0.25 A/g时,比电容为173 F/g.在10 mV/s的扫描速度下,循环测试1000圈后比电容保持率高达97%. 相似文献
4.
碳酸铵共沉淀法制备纳米活性NiO的研究 总被引:3,自引:0,他引:3
介绍了碳酸铵共沉淀法制和轩纳米活性NiO的新方法,研究了工艺过程的主要影响因素,经X-射线衍射分析、X-射线荧光分析和透射电镜观测表明,活性NiO为立方晶体结构,纯度超过99.66%、晶体粒度达到7nm左右。 相似文献
5.
以NaCl为稀释剂,NaOH,NiCl2.6H2O为原料,采用固相机械化学反应制备Ni(OH)2前驱体。前驱体经焙烧可制得呈面心立方晶型的黑色NiO纳米晶粉末。用差热/热重分析前驱体的热处理过程,X射线衍射表征样品的结构,透射电镜(transmission electron microscope,TEM)观察粉末的形貌特征。TEM观察表明:产物为立方形颗粒,颗粒平均尺寸在80 nm左右,呈现良好的单分散性。用循环伏安法测试NiO的电化学性能,并计算其比电容值,考察前驱体焙烧温度对所得NiO电极的电化学性能的影响。研究发现:400℃处理所得NiO纳米材料在同一扫描速率下的充放电电流最大,比电容值最大,当扫描速度为1 mV/s时其比电容值可达209.32 F/g。 相似文献
6.
介绍了碳酸铵共沉淀法制备纳米活性NiO的新方法 ,研究了工艺过程的主要影响因素。经X 射线衍射分析、X 射线荧光分析和透射电镜观测表明 :活性NiO为立方晶体结构、纯度超过 99 6 6 %、晶体粒度达到 7nm左右 相似文献
7.
8.
9.
通过水热合成法,以葡萄糖酸钠与硝酸镍为起始原料,一步法制备了前驱体碳杂Ni(OH)2复合微球(C-Ni(OH)2)。然后以制得的C-Ni(OH)2微球前驱体,在空气氛围下进行焙烧,制备出镂空结构NiO微球。通过场发射扫描电镜(FE-SEM)、X-射线衍射(XRD)、X-射线能谱(EDS)和氮气吸附脱附(EBT)等实验方法对其进行了分析,结果表明该微球主要是由几十个纳米的颗粒结合而成。由于前驱体为碳杂Ni(OH)2复合微球,氢氧化镍不仅存在于该微球的表面,而是存在于整个微球中,所以导致了部分焙烧出的NiO空心球出现了特殊的"球套球"的结构。 相似文献
10.
11.
以竹炭作为生物模板,结合浸渍-煅烧法制备了空心纳米NiO。XRD测试结果表明,产物为立方相NiO;TEM测试结果表明样品为空心六面体结构,其平均粒径为100~150 nm,孔径为50~100 nm,且壳层结构均由片状纳米晶粒构筑而成。 相似文献
12.
13.
通过天然产物松香制备松香基表面活性剂,利用该表面活性剂调控晶体生长制备出多级Ni(OH)2纳米结构,并进一步制备成NiO微球。通过FT-IR、NMR、XRD、SEM、TEM等表征确定了NiO的形貌及结构,通过BET等表征测试确定了其为多级多孔的结构。FT-IR、UV研究表明该多级纳米NiO对刚果红具有极高的吸附能力,其最大吸附量为657.89 mg/g,远优于商业NiO(337.18 mg/g)。研究结果表明:在pH值3,质量浓度为50 mg/L刚果红20 mL,吸附剂NiO适宜质量为16.8 mg时,吸附10 min达到平衡,平衡吸附量为50 mg/g。NiO对刚果红的吸附更符合Freundlich模型,吸附容易进行,吸附是吸热过程;吸附动力学符合准二级动力学方程,吸附过程以化学吸附为主。循环5次使用后吸附效率没有明显减弱,对刚果红去除率保持98%。 相似文献
14.
Rinaldo M. Silva Rafael A. Raimundo Willian V. Fernandes Sandro M. Torres Vinícius D. Silva João P.F. Grilo Marco A. Morales Daniel A. Macedo 《Ceramics International》2018,44(6):6152-6156
Core-shell structured magnetic Ni/NiO powders were prepared by a proteic sol-gel route. Commercial gelatin and nickel nitrate were used as precursor materials. The synthesized material was calcined in air at 500 °C and further investigated by XRD, VSM and TEM. In order to investigate the effects of the structure on the magnetic properties, NiO powders were synthesized by three other methods for sake of comparison: citrate method, nitrate calcination and combustion method. XRD results revealed that the core-shell structured material is composed of 84.8 wt% NiO and 15.2 wt% Ni, while the samples from other methods are single phase. Hysteresis loop at room temperature showed a strong ferromagnetic behavior for samples prepared by proteic sol-gel and citrate methods. Powders from nitrate calcination and combustion showed weak ferromagnetic behavior most likely attributed to unpaired moments in their nanoparticles. The overall results showed that the proteic sol-gel method is a versatile chemical way to prepare Ni/NiO core-shell powders with high ferromagnetic signals. 相似文献
15.
《Ceramics International》2017,43(10):7508-7515
A novel hierarchical heterostructure consisting of porous NiO nanosheets and flower-like ZnO assembled by hexagonal nanorods was successfully fabricated by a simple two-step hydrothermal approach. Flower-like ZnO was obtained by the first step hydrothermal method. Through the second step hydrothermal method, porous NiO nanosheets grew on the surface of flower-like ZnO to realize integration of ZnO and NiO, so the p-n heterostructure between ZnO and NiO formed. The samples were investigated by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and energy dispersive X-ray (EDX). Gas sensing test results showed that the sensor based on NiO/ZnO composite exhibited superior sensing properties to acetone. The sensor response to 100 ppm acetone was about 205.14 at the optimum working temperature of 240 °C, and the response and recovery times were about 7 and 20 s, respectively. The enhanced response might be attributed to heterojunction and larger specific surface area provided by attached porous NiO nanosheets. The rapid response and recovery characteristics and improved selectivity attributed to the porous structure and good catalytic actions of NiO nanosheets. 相似文献
16.
17.
采用控制沉淀法制备了Ni(OH)2前驱体,在空气氛中、400℃下煅烧2h,得到NiO材料。采用化学还原法,在NiO中掺杂Co,制得NiO-Co复合材料。通过XRD、SEM、充放电测试、循环伏安法和交流阻抗实验对其结构、形貌和性能进行表征,探讨了嵌脱锂行为。结果表明,掺杂Co后电极电导率增大,在充电过程中促进部分SEI膜的分解,因而循环性能明显得到提高;循环30次后,NiO-Co复合材料的可逆比容量仍有550mAh/g,容量保持率为87.4%,明显高于纯NiO材料(343mAh/g和49.1%)。 相似文献