A novel LEuH/PVA luminescent hydrogel with ammonia response and self-recovery luminescence behavior

Searching for fast-responding, recycling, and portable materials for ammonia detection is highly desirable in industrial fields. Here, we report a robust luminescent hydrogel consisting of PVA and layered rare-earth hydroxide (LRH) material synthesized via an in situ method. The hydrogel exhibits a unique response time to different ammonia environments via a fluorescence quenching pattern, and the whole process can be recognized by the naked eye. Furthermore, a fluorescence self-recovery behavior enables the potential application of the hydrogel in ammonia detection. The mechanism of response was elucidated by analyzing fluorescence spectra and studying the changes of hydrogen bonds in the hydrogel.