Synthesis of hollow YMnO3 under premixed stagnation flame control and its application in H2S detection

Flame synthesis method for producing hollow YMnO3 spherical nanomaterials. • The sensor exhibits a response value of 4.81 toward H2S at its optimal operating temperature of 220°C. • The sensor exhibits excellent selectivity for H2S gas detection among four interfering gases. • The sensor exhibits a response of 1.31 to 1ppm H2S at its minimum detection limit. Hydrogen sulfide (H 2 S) is a highly toxic, flammable, and corrosive gas that poses a serious threat to human health and industrial safety. Metal-oxide-semiconductor (MOS) sensors offer a highly promising technical solution for precise H₂S monitoring due to their advantages of simple fabrication, rapid response, and strong stability. This study synthesized hollow-structured YMnO 3 spherical nanostructures using the premixed stagnation flame method. By systematically regulating the O 2 /C 2 H 4 equivalence ratio and carrier gas flow rate, the effects of different flame conditions on the product morphology and gas-sensing properties were investigated. Experiments demonstrate that YMnO 3 synthesized under conditions of an O 2 /C 2 H 4 equivalent ratio of 5.19 and a carrier gas flow rate of 8.16 L/min exhibits the most pronounced hollow structure. At an optimal operating temperature of 220°C, the sensor has a maximum response value of 4.81 at 30 ppm H₂S, which is 1.64 times higher than that of spherical YMnO 3 sensors. Even at a low H 2 S concentration of 1 ppm, the sensor still exhibited a response value of 1.31. Furthermore, the sensor exhibited excellent selectivity and long-term stability. The enhanced performance of the hollow-structured YMnO 3 sensor is attributed to the abundant surface-active sites and diffusion channels provided by the inner and outer surfaces of the hollow nanoparticles. This facilitates the diffusion and adsorption of H 2 S gas in the sensing layer. This study achieved morphology control of hollow-structured YMnO 3 by regulating flame conditions, providing a solution for the development of sensors for efficient detection of H 2 S gas based on morphology control technology. Download: Download high-res image (205KB) Download: Download full-size image