材料期刊网

以硝酸镍、尿素及氟化铵为原料,采用水热法在炭布(CC)表面生长β-Ni(OH)2纳米片.XPS结果表明酸处理后的炭布(ACC)上含有更多活性官能团,有利于β-Ni(OH)2纳米片在炭布上的生长.XRD结果表明,炭布表面的β-Ni(OH)2纳米片结晶良好,晶格完整.通过分时采样的SEM照片,研究炭布表面β-Ni(OH)2的生长过程.反应初始阶段,炭布表面生长微小β-Ni(OH)2颗粒或片.随着反应进行,炭布表面的纳米片不断团聚生长.当反应时间为6 h时,炭布表面均匀布满β-Ni(OH)2纳米片,直径约为1 μm,厚度约为10 nm.随着反应的继续进行,β-Ni(OH)2纳米片堆叠.反应时间为12 h时,炭布表面均匀分布多层的β-Ni(OH)2纳米片,厚度约为200 nm.反应时间为6 h时所得样品具有优异的超级电容器性能,电流密度为1 A·g-1时,比电容为815.67 F·g-1.循环次数达到4 000次时,比电容仍保留98.1%.

Carbon cloth (CC) coated with β-Ni(OH)2 nanoflakes was prepared by a hydrothermal method using nickel nitrate, urea and ammonium fluoride as the reaction system, and was characterized by SEM, XPS and XRD.Results indicated that the acid treatment of the CC introduced more active functional groups on its surface, which was beneficial to the coating of the β-Ni(OH)2.The β-Ni(OH)2 nanoflakes were of high purity, and their formation mechanism on the CC was investigated by observing their morphology at different reaction times.It was revealed that the β-Ni(OH)2 were initially present in the form of discrete nanoparticles and nanoflakes and after 6 h formed a continuous and well-crystallized β-Ni(OH)2 nanoflake with diameter and thickness of 1 μm and 10 nm, respectively.Nanoflakes continued to form, grow and overlap and after 12 h the thickness had increased to 200 nm.The sample at 6 h had the highest specific capacitance of 815.67 F·g-1 at a current density of 1 A·g-1, and retained 98.1% of its initial capacitance after 4 000 cycles.