Ni-Doped SnO 2 Nanoparticles for Sensing and Photocatalysis

Ni-doped SnO 2 nanoparticles were synthesized by a coprecipitation route and showed superior properties for a series of different applications. The 1 atom % Ni-doped SnO 2 NPs exhibited excellent electrochemical performance as supercapacitors to deliver a specific capacitance of 793 F g –1 at an applied current density of 2.5 A g –1 in a KOH electrolyte while retaining its capacitance over 1250 cycles. The energy-dependent (100, 150, and 200 μJ) nonlinear absorption behavior of the Ni-doped SnO 2 NPs was investigated and found to be due to the effective two-photon absorption with free carrier absorption. A clad-modified fiber-optic gas-sensor setup was used to sense the ammonia at ambient temperature. Further, the photocatalytic degradation of Rhodamine B, Congo red, and Direct red dyes by the Ni-doped SnO 2 NPs was examined under visible-light irradiation.