LAUSR

Abstract A visible light active hetero structure composite PbBi2Nb2O9 (Bulk)/TiO2(Nano) consisting of bulk PbBi2Nb2O9 with high crystallinity, decorated with TiO2 nano particles was prepared using Solid-State Reaction method, and sol-gel synthesis respectively. We have investigated the structural, morphological and optical properties of semiconductor composite PbBi2Nb2O9/TiO2 using powder XRD, FESEM, HR-TEM, UV-DRS techniques with the optimized preparation conditions towards the tunability in the visible light responsive for various loadings of TiO2 nano particles over the bulk PbBi2Nb2O9.  Further the relationship between the photo degradation performances of organic pollutant dye such as methylene blue with the various loading of TiO2 nano particles over the bulk PbBi2Nb2O9   were investigated and studied by using the simulated sunlight. The highest percentage of photodegradation with methylene blue as an organic pollutant dye was observed for the TiO2 loading with molar ratio 0.992 over PbBi2Nb2O9 without using any co-catalyst. Also the photocatalytic activities of the prepared composite PbBi2Nb2O9 (Bulk)/TiO2(Nano) were observed as higher than the bulk PbBi2Nb2O9. Based on the optical and photodegradation studies a reasonable mechanism for the photodegradation of composite PbBi2Nb2O9 (Bulk)/ TiO2 (Nano) under visible light (λ≥420 nm) is proposed for the solar photo catalytic applications such as organic pollutant (i.e. methylene blue etc) degradation and its related environmental applications etc.