Ammonia Sensor Based on Co2+/SCN− Modified Core-Shell MCM-41 for Rapid Naked-Eye Colorimetric Detection

Mesoporous silica materials have been widely used as gas adsorbents due to their excellent adsorption ability, large specific surface area, simple preparation process, and convenient functionalization. In this study, a core–shell mesoporous material MCM-41@SiO2 was synthesized functionalized by CoCl2, subsequently KSCN, prepare an ammonia adsorbent. The adsorbent proved possess high good sphericity, uniform size, dispersibility, capability following DLS, SEM, TEM, static study. Moreover, the successful functionalization thermal stability were confirmed FT-IR, XPS, TGA. then fabricate glass tube sensor for rapid naked-eye detection of gas. showed performance in terms sensing speed, selectivity, accuracy, reusability. Within 5 s, NH3 could be detected discoloration, wide concentration from 20 1000 ppm detected. It also linear relationship between discoloration length concentration. A reversible color change blue yellow indicated presence NH3, which attributed formation disassembly ammonia-containing complex [Co(NH3)6(NCS)2]. With fast adsorption, properties, holds promise indoor other more complicated situations.