Ultra-rapid and reusable luminescent gas sensor based on MAPbX3 quantum dots nano-confined in glass

Detecting hazardous hydrogen halides (HX, X = Cl, Br, and I) gas is critical for human health and ecological safety. A luminescent sensor based on anion exchange reaction (AER) in perovskite could offer a cost-effective approach. However, resolving the challenging issues of instability and the acceleration requirement of AER is highly desired for practical applications. Here, we develop an ultra-rapid, sensitive, and reusable HCl luminescent gas sensor through nanoconfining MAPbBr3 quantum dots (QDs) into a transparent nanoporous glass (NG) matrix, successfully extending perovskite glass to the organic–inorganic system, which exhibits enhanced AER sensitivity. Utilizing enhanced transport efficiency of reactants within NG, HCl gas could be rapidly adsorbed into the nanopores and undergo ultra-rapid AER with the embedded perovskite QDs. In addition, the device stability could be fostered by the physical protection of glass matrix. After being simply integrated with UV LED, the MAPbBr3-NG exhibits an ultra-rapid response time within 2 s at a HCl gas concentration of 5 ppm. Furthermore, this luminescent gas sensor demonstrates robust performance, retaining functionality over 10 reuse cycles. This compact, cost-effective, and highly sensitive device with rapid response capability could open a promising avenue for research on HX detection while expanding the practical applications of perovskite-based devices.