Green-Synthesized rGO/Nd ₂ WO ₆ Nanocomposite via Phyllanthus amarus : Sustainable Multifunctionality for Environmental and Biomedical Applications

This study focuses on the synthesis of an rGO/Nd₂WO₆ nanocomposite using an environmentally friendly green approach, employing Phyllanthus amarus leaf extract. The bioactive compounds in the plant extract facilitate simultaneous reduction and stabilization of the nanocomposite, eliminating the need for harmful chemicals. The resulting nanomaterials were thoroughly characterized by using the Brunauer-Emmett-Teller technique, Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, ultraviolet-visible diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, and X-ray diffraction analyses to confirm their structural, morphological, and optical properties. The photocatalytic performance of rGO/Nd₂WO₆ was evaluated through the degradation of methylene blue under sunlight irradiation, achieving a degradation efficiency of 82.29%, which was significantly higher than those of WO₃ (61%) and Nd₂WO₆ (73.65%). The enhanced photocatalytic activity is attributed to the synergistic effect of rGO, which promotes efficient charge carrier separation, extended light absorption, and improved electron transport. Kinetic studies revealed a pseudo-first-order reaction mechanism, with rGO/Nd₂WO₆ exhibiting the highest rate constant (k = 0.0413 min⁻¹). Additionally, the nanocomposite demonstrated excellent antioxidant activity, as assessed by the DPPH radical scavenging assay and antibacterial activity. These findings underscore the use of Phyllanthus amarus extract for the sustainable synthesis of high-performance photocatalytic and antioxidant nanomaterials, positioning rGO/Nd₂WO₆ as a promising candidate for wastewater treatment, environmental remediation, and potential biomedical applications.