Fluoride ion sensor based on LaF3 nanocrystals prepared by low-temperature process

This study addresses the advantages of using a lanthanum fluoride (LaF3) nanocrystals-based fluoride ion sensor. We propose a method that enables the preparation of fluoride ion-selective LaF3 nanocrystals at low temperatures (less than 80 °C) in contrast to the conventional method, wherein high temperatures (1000 °C and above) are required for preparing a single-crystal LaF3. An LaF3 nanocrystal with a diameter below 5 nm in the (001) plane was synthesized and subsequently deposited on a Ti electrode. The sensor exhibited a selective response to fluoride ions. This process does not require high-temperature and vacuum equipment and conditions, thus enabling easy production of fluoride ion sensors.