This work focused on employing Calotropis gigantea leaf extract as reducing agent/fuel and (Zn(NO ₃ ) ₂ .6H ₂ O), (Cu(NO ₃ ) ₂ .3H ₂ O) as precursors to synthesise ZnO–CuO nanocomposite by solution combustion method. Prepared nanocomposites were characterised using x-ray powder diffraction (XRD), scanning electron microscope (SEM) with energy dispersive x-ray analysis (EDAX), high-resolution transmission electron microscopy (HR-TEM) and Fourier transform infrared spectroscopy (FT-IR). XRD result revealed crystalline nature with average crystallite size of 35 nm. SEM images indicate that particles are agglomerated and EDAX confirms the composition of elements with pure phase. HR-TEM images indicated that average sizes of the prepared ZnO–CuO nanocomposite were 10–40 nm with spherical and hexagonal shapes. The presence of functional groups such as Zn−O, Cu−O, −OH, −C–O, and C–H was confirmed by FT-IR spectrum. The optical energy bandgap was estimated using Kubelka-Munk equation by the aid of diffuse reflectance spectroscopy (DRS). The synthesised nanocomposite showed superior photocatalytic activity of degradation efficiency 97.93% against methylene blue dye. Further, anti - bacterial activity was investigated by agar well diffusion procedure against two bacterial strains ( Escherichia coli and Staphylococcus aureus) and significant zone of inhibition to the bacterial strains was observed.

A series of novel unsymmetrical bithiophene substituted oxadiazole derivatives 2(a–e) were designed and synthesised by employing palladium catalysed Suzuki cross coupling reaction. These bipolar molecules consist of bithiophene as an electron donor unit (D) and electron transporting oxadiazole as acceptor unit (A). The structural integrity of all the new compounds was confirmed by ¹H NMR, ¹³C NMR and GC-MS analysis. The photophysical and electrochemical properties have been studied in detail using UV-Vis absorption, fluorescence spectroscopy and CV measurements. All compounds emit intense green fluorescence with good quantum yields. Density functional theory computations have been carried out to understand the structure–property relationship, the computed values are found to be in good agreement with the experimental results. The results demonstrated that the novel bithiophene containing oxadiazole derivatives could play an important role in organic optoelectronics.