Development of Heterostructured Ferroelectric SrZrO₃/CdS Photocatalysts with Enhanced Surface Area and Photocatalytic Activity.

This paper reports the attempt to develop an efficient heterostructure photocatalyst by employing SrZrO₃ as ferroelectric substrate with deposited nanostructured CdS semiconductor on the surface. Primarily bare SrZrO₃ and CdS nanoparticles were synthesized by using polymeric citrate precursor and co-precipitation routes, respectively. The chemical deposition technique was used to develop the CdS over the surface of the pre-synthesized SrZrO₃ nanoparticles. The synthesized bare nanoparticles and their heterostructure were characterized by XRD which shows the formation of orthorhombic and face centred cubic (FCC) phases of SrZrO₃ and CdS, respectively. TEM was used to estimate the morphology and particle size of as-synthesized nanoparticles, which shows the average particle size of 14, 24 and 25 nm for SrZrO₃, CdS and SrZrO₃/CdS, respectively. The BET surface area of SrZrO₃, CdS and SrZrO₃/CdS samples was found to be 299, 304 and 312 m2/g respectively. Methylene blue was used as model pollutant to determine the photocatalytic activity of the synthesized nanomaterials. The heterostructure shows an enhanced activity as compared to bare nanoparticles. Dielectric constant and dielectric loss of the nanoparticles was investigated as a function of frequency at room temperature and as a function of temperature at 500 kHz. The room temperature dielectric constant for SrZrO₃, CdS and SrZrO₃/CdS was found to be 13.2, 17.8 and 25.5 respectively at 100 kHz.