Synthesis, Humidity Sensing, Photocatalytic and Antimicrobial Properties of Thin Film Nanoporous PbWO4-WO3 Nanocomposites

A humidity sensor thin film based on nanoporous PbWO4-WO3 composites has been prepared by spin coating technique with different weight ratio of PbWO4 (Pb) and WO3 (WO) (PWWO-01, PWWO-82, PWWO-64, PWWO-46, PWWO-28, PWWO-01) and their humidity sensing properties have also been investigated at different relative humidity (RH) in the range of 5% - 98% at room temperature with dc resistance. It is found that composite PWWO-28 show best humidity sensing properties with the sensitivity factor value of (Sf) 3733. The response and recovery time of humidity sensor are about 50 s and 120 s, respectively. High sensitivity, narrow hysteresis loop, rapid response and recovery, prominent stability and good repeatability are obtained. Synthesized PbWO4-WO3 composites were characterized by power X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, BET and photoluminescence studies. The photocatalytic result demonstrated photocatalytic efficiency of nonporous PWWO-28 composite.  The antimicrobial activity of the composites was determined by disc diffusion method.