NiO sensitized porous ZnSnO3 nanocubes for enhanced formaldehyde gas-sensing performance†

Abstract

As a carcinogen, low concentration and high sensitivity detection of formaldehyde is crucial. NiO sensitized porous ZnSnO₃ nanocubes were synthesized through a water bath coprecipitation process followed by subsequent calcination for formaldehyde vapor detection. NiO sensitized porous ZnSnO₃ nanocubes exhibit a uniform size distribution of approximately 100 nm. The addition of NiO increases the oxygen vacancy concentration while suppressing electron–hole recombination processes. Operating at 180 °C, gas sensors based on NiO sensitized porous ZnSnO₃ nanocubes exhibit a significant response to 50 ppm formaldehyde vapor. The 7% NiO/ZnSnO₃ sensor demonstrates a higher sensitivity of 60.5 compared to other ratios. When detecting formaldehyde at a concentration of 1 ppm, the 7% NiO/ZnSnO₃ sensor exhibits a sensitivity of 15.9, which indicates its low detection limit. Additionally, it demonstrates a strong linear response to formaldehyde concentration variations, along with excellent selectivity and good stability to 50 ppm formaldehyde. The excellent gas sensitivity of the 7% NiO/ZnSnO₃ nanocubes sensor is attributed to the unique p–n heterojunction and abundant oxygen vacancies.