Microwave-mediated synthesis of spinel CuAlO nanocomposites for enhanced electrochemical and catalytic performance

Abstract: The present study explores synthesis of spinel copper aluminate nanocomposites (CuAlO NCs) for electrochemical applications and solvent-free synthesis of xanthanedione derivatives. CuAlO NCs were synthesized from copper nitrate and aluminum nitrate with/without use of sodium dodecyl sulfate (SDS) by aqueous precipitation and microwave-assisted (MW) technique. As-synthesized CuAlO NCs were characterized structurally and morphologically using X-ray diffraction (XRD) analysis, Fourier-transform infrared (FT-IR) spectroscopy, diffuse reflectance spectroscopy (DRS), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM). Formation of cubic spinel structure after calcination at 900 °C was confirmed by XRD analysis, while Raman, XPS, and EDS validated the composition and purity. TEM revealed that the particles had uniform nanosphere shape with average size of 10 nm for microwave-assisted with surfactant (MWS-CuAlO), while aqueous precipitation with surfactant (APS-CuAlO) NCs exhibited nanograins with particle size of 17 nm. AFM revealed higher surface roughness for MWS-CuAlO NCs than APS-CuAlO NCs. The electrochemical performance of the CuAlO NCs was examined in aqueous NaSO (1 M) as electrolyte using cyclic voltammetry (CV), revealing that the MWS-CuAlO NCs demonstrated high specific capacitance (125 F g at current density of 0.5 mA cm). Furthermore, one-pot, facile, eco-friendly MWS-CuAlO NC-catalyzed synthesis of xanthanediones was developed, exhibiting excellent yield and reusability with negligible reduction in efficiency even after four consecutive cycles. Graphical Abstract: MWS-CuAlO NCs showed enhanced electrochemical and catalytic performance.[Figure not available: see fulltext.].