Ammonia-Assisted Growth of CoSn(OH)6 Nanostructures and Their Electrochemical Performances for Supercapacitor.

In this work, ammonia-assisted one step growth of SnO2 and mixed metal hydroxide CoSn(OH)6 on Ni foam is illustrated. The nanostructured films grown on Ni foam are highly porous in nature. The CoSn(OH)6 nanostructures were deposited using three different molar ratios of Sn/Co precursors i.e., 1:1, 1:2 and 2:1 and their performances as supercapacitor have been investigated and compared with pristine SnO2. Interestingly, the CoSn(OH)6 thin films prepared with 1:2 molar ratio of Sn/Co showed remarkably high areal capacitance and good cyclic stability. It is believed that the presence of different metal cations and their valence states along with the porous nanostructure makes the material outstanding as supercapacitor. The highest areal capacitance of 4189 mF cm-2 was obtained at a current density of 2 mA cm-2 for CoSn(OH)6 thin films offering an excellent cyclic stability with a capacity retention of 90.3% after 2000 cycles.