Platinum Nanoparticle Loading of Boron Nitride Aerogel and Its Use as a Novel Material for Low-Power Catalytic Gas Sensing

A high-surface-area, highly crystalline boron nitride aerogel synthesized with nonhazardous reactants has been loaded with crystalline platinum nanoparticles to form a novel nanomaterial that exhibits many advantages for use in a catalytic gas sensing application. The platinum nanoparticle-loaded boron nitride aerogel integrated onto a microheater platform allows for calorimetric propane detection. The boron nitride aerogel exhibits thermal stability up to 900°C and supports disperse platinum nanoparticles, with no sintering observed after 24 h of high-temperature testing. The high thermal conductivity and low density of the boron nitride aerogel result in an order of magnitude faster response and recovery times (<2 s) than reported on alumina support and allow for 10% duty cycling of the microheater with no loss in sensitivity. The resulting 1.5 mW sensor power consumption is two orders of magnitude less than commercially available catalytic gas sensors and unlocks the potential for wireless, battery-powered catalytic gas sensing

High Surface Area MoS2/Graphene Hybrid Aerogel for Ultrasensitive NO2 Detection

A MoS /graphene hybrid aerogel synthesized with two-dimensional MoS sheets coating a high surface area graphene aerogel scaffold is characterized and used for ultrasensitive NO detection. The combination of graphene and MoS leads to improved sensing properties with the graphene scaffold providing high specific surface area and high electrical and thermal conductivity and the single to few-layer MoS sheets providing high sensitivity and selectivity to NO . The hybrid aerogel is integrated onto a low-power microheater platform to probe the gas sensing performance. At room temperature, the sensor exhibits an ultralow detection limit of 50 ppb NO . By heating the material to 200 °C, the response and recovery times to reach 90% of the final signal decrease to <1 min, while retaining the low detection limit. The MoS /graphene hybrid also shows good selectivity for NO against H and CO, especially when compared to bare graphene aerogel. The unique structure of the hybrid aerogel is responsible for the ultrasensitive, selective, and fast NO sensing. The improved sensing performance of this hybrid aerogel also suggests the possibility of other 2D material combinations for further sensing applications. 2 2 2 2 2 2 2 2 2 2