Gu Renjie, Li Xuelei, Cheng Kunpeng, Wen Lixiong
State Key Laboratory of Organic-Inorganic Composites, Beijing University of Chemical Technology Beijing 100029 China
Research Center of the Ministry of Education for High Gravity Engineering and Technology, Beijing University of Chemical Technology Beijing 100029 China.
RSC Adv. 2019 Aug 15;9(44):25677-25689. doi: 10.1039/c9ra03183a. eCollection 2019 Aug 13.
A micro-impinging stream reactor (MISR) consisting of a commercial T-junction and steel capillaries, which is of intensified micromixing efficiency as compared with traditional stirred reactors (STR), was applied for the preparation of Co and Al co-doped Ni(OH) nanocomposites and their modification with reduced graphene oxide (RGO). The co-precipitation preparation process was conducted under precisely controlled proportions and concentrations of reactants in the MISR. Therefore, element analysis showed a higher uniform distribution of metal ions within the nanocomposites obtained through the MISR. The structural characterization and electrochemical measurements also showed that the MISR-prepared metal-doped nanocomposites were of more uniform dispersion and superior electrochemical performance than those prepared with STR. In addition, by modifying with RGO in the MISR, the electrochemical performance of Co and Al co-doped Ni(OH) nanocomposites could be further improved. The Co and Al co-doped Ni(OH)/RGO prepared under optimal conditions achieved an ultrahigh specific capacitance of 2389.5 F g at the current density of 1 A g and displayed an excellent cycling stability with 83.7% retention of the initial capacitance after 1000 charge/discharge cycles in 6 M KOH aqueous solution.
一种由商用T型接头和钢毛细管组成的微撞击流反应器（MISR），与传统搅拌反应器（STR）相比，具有更高的微混合效率，被用于制备钴和铝共掺杂的氢氧化镍纳米复合材料以及用还原氧化石墨烯（RGO）对其进行改性。在微撞击流反应器中，共沉淀制备过程是在反应物比例和浓度精确控制的条件下进行的。因此，元素分析表明，通过微撞击流反应器获得的纳米复合材料中金属离子的分布更加均匀。结构表征和电化学测量还表明，与用搅拌反应器制备的相比，微撞击流反应器制备的金属掺杂纳米复合材料具有更均匀的分散性和更优异的电化学性能。此外，通过在微撞击流反应器中用还原氧化石墨烯进行改性，钴和铝共掺杂的氢氧化镍纳米复合材料的电化学性能可以进一步提高。在最佳条件下制备的钴和铝共掺杂的氢氧化镍/还原氧化石墨烯在1 A g的电流密度下实现了2389.5 F g的超高比电容，并且在6 M氢氧化钾水溶液中经过1000次充放电循环后，显示出优异的循环稳定性，初始电容保留率为83.7%。
