Amine-Functionalized Black Phosphorus Nanosheets toward Ultrafast and Room-Temperature Trace Carbon Dioxide Sensing

Carbon dioxide (CO₂) poses a significant effect on global climate, indoor activity, and crop yield, thus necessitating real-time and high-performance detection. Traditional CO₂-sensing materials always suffer from weak and sluggish reaction, elevated operation temperature, and poor detection limit. To surmount these obstacles, in this work a series of amine-rich polymer functionalized black phosphorus nanosheets (BP) were prepared for room-temperature CO₂ detection. Superior to TMMAP or 3-DEAPTES modified counterparts, the BP-10% APTES sensor delivered a response of 28.5% and ultrafast response/recovery time of 4.7 s/4.8 s toward 10 ppm of CO₂ under 36% RH at 22 °C, a lowest detection limit of 5 ppm, as well as excellent selectivity. Also, a nice repeatability and long-term operation stability were demonstrated. Thus, BP-APTES composites offer a promising strategy for high-performance CO₂ detection in terms of high sensitivity, low power-consumption, and convenient fabrication, and showcase brilliant prospects in portable optoelectronic detection systems and the Internet of Things.