Highly photoactive heterostructures of PbO quantum dots on TiO2

Abstract

We present a non-hydrolytic sol-gel combustion method for synthesizing nanocomposites of PbO quantum dots on anatase TiO 2 with a high surface area. XRD, electron microscopy, DRS, cathodoluminescence and BET were employed for structural, microstructural and optical characterization of the composites. The photocatalytic activity of TiO 2 and PbO/TiO 2 was investigated and compared with Degussa P-25. The results indicate that the photocatalytic activity of quantum dot dispersed TiO 2 is higher than that of bare TiO 2 and much higher than that of commercial Degussa P-25.The origin of enhanced photoreactivity of the synthesized material can be assigned to a synergetic effect of high surface area, higher number of active sites and an engineered band structure in the heterostructure. The mechanisms for photocatalytic activity are discussed based on production of photogenerated reactive species. The knowledge gained through this report open up ideal synthesis routes for designing advanced functional heterostructures with engineered band structure and has important implications in solar energy based applications. 80 23607316; Tel: +91 80 22933255 † Electronic supplementary information (ESI) available: Fig. S1: HRTEM micrograph of PbO/TiO 2 shows that d-spacing of 2.8Å corresponding to the (200) plane of PbO. Fig. S2: EDS spectra of PbO/TiO 2 composite showing presence of Pb, Ti, O and with almost 10 mol% of PbO. Fig. S3: XPS Ti 2p spectra of synthesized materials. See

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