Lead-Free Double Perovskite Cs2AgIn1-x Er x Cl6 Fluoride Glass with Highly Stable Mid-Infrared Luminescence for Monitoring CO2 in Hydrogen Energy

Carbon dioxide makes the hydrogen combustion processunstable anddestructive, thus affecting the efficiency and effectiveness of hydrogenenergy use. Thus, it is very important to monitor CO2 inhydrogen gas. All-inorganic perovskites are used for optical sensingdue to their excellent optical properties, and photoluminescence sensorsmade from them can monitor gas concentration. However, the toxicityand intrinsic instability of lead-based perovskites have limited theircommercial development. Meanwhile, perovskites have rarely been studiedin the mid-infrared range. Herein, Cs2AgIn1-x Er x Cl6-ZBLANperovskite fluoride glasses with outstanding mid-infrared luminescenceare successfully prepared. A CO2 monitor device is fabricatedusing a Cs2AgIn1-x Er x Cl6-ZBLAN perovskite fluorideglass. The dense and inert nature of the glass is used to isolatethe lead-free perovskite Cs2AgInCl6 from theexternal environment, thereby improving stability. The luminescenceintensity of the Cs2AgIn1-x Er x Cl6-ZBLAN perovskitefluoride glass can still be maintained at more than 90% of its originallevel after 35 h of continuous UV lamp irradiation at 365 nm. Thesubstitution of Er3+ for In3+ to form Cs2AgIn1-x Er x Cl6-ZBLAN perovskite fluoride glasses makes thempromising candidates for future mid-infrared-emitting materials. The concentration of CO2 gasin H-2 gas can be monitored with a device made of a Cs2AgIn1-x Er x Cl6-ZBLAN perovskite fluoride glass. Green, lead-freematerialsare conducive to the sustainable development of ecology.