Enhanced Sonocatalytic Degradation of Doxycycline in Water Using a Saccharum officinarum L.-Fabricated Au/Cu2O Nanocomposite

Nanocomposites (NCs) have demonstrated promising potential in water remediation, and their catalytic role in degrading hazardous water contaminants has been widely explored. In this study, binary NCs of gold and cuprous oxide (Au–Cu2O) were fabricated using a green protocol using Saccharum officinarum L. bagasse (SOLB) extract as a reducing and stabilizing agent to generate nanoparticles (NPs). The biomediated Au–Cu2O NC formation was validated by various studies and was utilized for degradation studies of antibiotics in water samples. Furthermore, the photocatalytic and sonocatalytic activity of Au–Cu2O NCs was analyzed for catalytic efficacy for the degradation of doxycycline (DC) in water samples. The studies set a trend in providing an efficient, green, and recyclable strategy for removing antibiotic DC contaminants and purifying water. The biogenically synthesized Au–Cu2O NCs show appreciable degradation for DC in both sonocatalytic and photocatalytic pathways, with 89.99 and 79.27% degradation observed, respectively. The degradation follows pseudo-first-order kinetics with a rate constant of 0.26 and 0.0432 min–1, respectively, observed in sonocatalytic and photocatalytic pathways. The mechanistic simplicity, reusability, and radical scavenging abilities of the synthesized NCs indicate the enhanced application of Au–Cu2O NCs in laboratory and real water samples.