ZnO decorated reduced graphene oxide (RGO-ZnO) nanocomposites synthesized via green Benedict's route for efficient water splitting applications and photocatalytic activity

A novel, low-temperature and cost-effective synthesis route for the fabrication of nanocatalysts was successfully developed by modifying the Benedict's method. In this method, glucose employed as the reducing agent for the preparation of crystalline zinc oxide (ZnO) nanoparticles and its composite with reduced graphene oxide (RGO-ZnO). The structural and morphological features the synthesized materials were thoroughly investigated using UV–vis. Spectroscopy, X-ray diffraction technique (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The RGO-ZnO nanocomposite showed remarkable electrocatalytic performance, proving enhanced selectivity towards the hydrogen evolution reaction (HER) in acidic media and the oxygen evolution reaction (OER) in alkaline media. Electroanalytical techniques like cyclic voltammetry (CV), linear sweep voltammetry (LSV), and chronoamperometry, long-established the improved electron transport and higher catalytic activity, with onset potentials of 0.410 V (HER) and 1.614 V (OER) to deliver a current density of 10 mA cm⁻², supporting excellent stability for over 24 h. Additionally, the nanocomposites proved their high efficiency in the photocatalytic degradation of organic dyes under UV light. The RGO-ZnO composite achieved 87 % degradation of methylene blue and rhodamine B within 10 min and 12 min by 84 % within, significantly outperforming original ZnO. Thus, the modified Benedict's method is a promising strategy for fabricating multifunctional nanomaterials for sustainable energy and environmental remediation applications.