Enhancing alcohol sensing properties of hydroxyapatite via synthesis of its composite with TiO2 nano-tube

Nano-composites are emerging class of materials with venerable physical and chemical properties useful for gas sensor applications. In the present work, we have successfully demonstrated utilization of TiO2 nano-tube and hydroxyapatite nano-composite thick films for sensing of alcohol vapours at lower temperature and lower concentrations. Various composites have been prepared by adding wt.% TiO2 nano-tube in hydroxyapatite host material. Various characterizations like XRD, TGA, FTIR and SEM were performed to know structural identification, thermal stability, functional groups and surface morphology, respectively. Among all composites, the 2 wt.% TiO2 nano-tube-hydroxyapatite nano-composite film exhibits pronounced sensing behaviour for the detection of alcohol vapour even at 10 ppm. The operating temperature was observed to be 30/45/105 degrees C for methanol/ethanol/propanol, whereas, for the same nano-composite material there was fast response and recovery time (100 and 30)/(110 and 40)/(180 and 90) seconds, respectively. These results concluded that nano-composite of TiO2 nano-tube and hydroxyapatite is capable of sensing alcohol vapours with their existence in ambient conditions as low as 10 ppm concentration compared to their native counterparts.