Synthesis, Characterization, Humidity Sensing, Antibacterial, Photocatalytic and Kinetic Studies of Novel HgWO4 – WO3 Nanocomposites

Abstract

Mercury tungstate (HgWO4) and tungsten trioxide (WO3) were prepared by co-precipitation method. The HgWO4 – WO3 composites were prepared in various mole ratios which were analyzed for structural examination by powder XRD, purity by EDAX, morphological data by SEM, Optical properties by UV absorption spectra, humidity sensing activity using humidity sensor, Antibacterial ability using diffusion technique and photocatalytic efficiency by photocatalytic studies. The humidity sensing properties of the nanocomposites shows that the nanocomposite HWWO-82 has the highest humidity sensitivity factor (Sf = R5%/ R98%) of 10034 with response and recovery time of 30 s, 90 s respectively. Antibacterial activity of nanocomposites was tested against gram-positive and gram-negative bacteria’s in which HWWO-82 shows good antibacterial activity. The photocatalytic efficiency was estimated by degradation of Rhodamine B using nanocomposite, which shows complete degradation after 3 hours of its contact with HWWO-28 photocatalyst. The kinetic study for adsorption and degradation efficiency follows pseudo second order and pseudo first order kinetics respectively. Based on the experimental data of the nanocomposites, the nanocomposites was analyzed to behave as good humidity sensor satisfying commercial expectations, good antibacterial agent and mild photocatalyst