In this particular experiment, a chain of conductive polymer graphene/polypyrrole (Gr/PPy) and BiPO4-or (Gr/PPy)-BiPO4-materials were prepared and used as moisture-sensitive materials. The structure and morphology of the conductive polymer (Gr/PPy)-BiPO4 materials were analyzed using an X-ray diffractometer, scanning electron microscopy, transmission electron microscopy, and energy-dispersive X-ray spectroscopy. Moreover, properties such as hysteresis loop, impedance, sensing response, and response and recovery time were calculated and evaluated using an inductance-capacitance-resistance analyzer. The data expressed that PPy/BiPO4, as prepared in this study, exhibited excellent sensing properties, with impedance changing by only a few orders of range. Furthermore, the response time and time of recovery were 340 s and 60 s, respectively, and negligible humidity hysteresis occurred at different relative humidities. Therefore, conductive PPy/BiPO4, as prepared in the present study, is an excellent candidate for application in humidity sensors.
Keywords: BiPO4; graphene; impedance; polypyrrole; sensing response.