Strontium titanate perovskite embedded reduced graphene oxide photoanode for dye-sensitized solar cell

Abstract

Simple chemical reduction process is followed to form strontium titanate perovskite nanoparticles (SrTiO3 NPs) embedded reduced graphene oxide nanocomposite (RGO-SrTiO3 NC). The optical band gap of the RGO-SrTiO3 NC is found as 3.24 eV. The XRD analysis reveals that the crystallite size of the RGO-SrTiO3 NC is considerably low (31.69 nm) when compared to the SrTiO3 NPs (56.93 nm). The Raman investigation establishes RGO existence in RGO-SrTiO3 NC. The C1s peak (285.02 eV) observed in the XPS spectrum of the RGO-SrTiO3 NC unveils modification of SrTiO3 by the RGO. The SEM examination indicate that the SrTiO3 NPs are embedded firmly on the RGO flakes by means of strong binding forces between RGO and SrTiO3 NPs. The SAED pattern of the RGO-SrTiO3NC is in agreement with its corresponding XRD pattern, confirming strong association between SrTiO3 NPs and RGO. The EDAX and elemental analysis of the RGO-SrTiO3 NC unveil existence of elemental peaks corresponding to Sr, Ti, C and O. The RGO-SrTiO3 NC exhibits significantly low PL intensity, indicating reduced charge recombination. The DSSC fabricated using the photoanode of RGO-SrTiO3 NC delivers an enhanced efficiency of 5.42% when compared to SrTiO3 NPs (2.59%) due to the presence of highly conducting RGO.