Superior ethanol-sensing properties based on Ni-doped SnO_2 p-n heterojunction hollow spheres

摘要

This paper reported a novel sensing material of porous Ni-doped SnO_2 hollow spheres with nanoheterostructures, which were synthesized by a low-cost and environment-friendly hydrother-mal strategy. In the process of synthesis, long-chain polymers nickel nitrilotriacetic acid (NiNTA) were formed previously and then successfully heteroconnected with SnO_2 through a series of hydrothermal reactions for the reason that nitrilotriacetic acid (NTA) could be dissolved in the aqueous solution of NaSnO_3, leading to the complete change of previous morphology. The response of the sensor based on porous Ni-doped SnO_2 hollow spheres is up to 59 at l00ppm ethanol and the detection limit can be dropped to 1 ppm-level, which exhibits enhanced response compared with many ethanol sensors based on pure SnO_2 hollow spheres. Such good performance is probably attributed to the formation of p-n junctions between NiO and SnO_2, which increase the resistance of sensor and the depletion layers.