Enhanced formaldehyde detection based on Ni doping of SnO 2 nanoparticles by one-step synthesis

Abstract In this work, SnO 2 nanoparticles with Ni doping were synthesized via a facile one-step hydrothermal route. The addition of Ni to SnO 2 lead to significant enhanced response to formaldehyde (HCHO). The Ni-doped SnO 2 materials were used to fabricate HCHO gas sensors and the comprehensive HCHO-sensing properties under diverse working temperatures were tested and studied. With suitable Ni concentration, the SnO 2 nanoparticles exhibited a 10 times sensing enhancement with high gas response, excellent selectivity and good stability. Furthermore, the limit of detection (LOD) was experimentally figured out to be as low as 120 ppb, which is much lower than the threshold exposure limit of HCHO proposed by American Conference of Governmental Industrial Hygienists. Importantly, the excellent performances of the as-fabricated gas-sensing devices make Ni-doped SnO 2 a promising candidate for HCHO sensing applications. This synthesis strategy here can also give guidance for designing high-performance HCHO gas sensors.