FeMn<sub>2</sub>O<sub>4</sub>/GO Z-Scheme Heterostructure: A Bifunctional Nanocomposite for Photocatalytic Drug Degradation and Sustainable Hydrogen Production
Chandraleka Chinnasamy, Nagapandiselvi Perumal
Abstract
The design and construction of efficient nanocomposites for pollutant degradation and hydrogen generation are promising strategies for advancing environmental remediation and renewable energy. In this regard, spinel oxides and graphene oxide have attracted much attention due to their unique properties. Specifically, spinel oxides deliver abundant active sites and efficient redox capabilities, while graphene oxide is recognized for its high electrical conductivity, large surface area, and effective charge carrier transport. Integrating them is expected to combine the above properties, aiming to enhance charge separation and catalytic performance as well as HER evolution. In this study, a heterostructure nanocomposite of FeMn 2 O 4 /GO was synthesized using an ultrasonication method, with varying concentrations of GO and FeMn 2 O 4 . The as-prepared nanocomposite’s structural, morphological, optical, and electrical properties were analyzed using various analytical techniques, including XRD, RAMAN, SEM, TEM, XPS, UV–vis, PL, photocurrent, and EIS. Among the different weight percentages, the FMO 55 /GO 45 nanocomposite exhibited a higher degradation efficiency of CIP, achieving 99.5% within 50 min through a Z-scheme mechanism. Moreover, the electrocatalytic measurements of the FeMn 2 O 4 /GO nanocomposite were analyzed by the hydrogen evolution reaction (HER) within an acidic medium. Electrochemical analyses revealed a low overpotential (−240 mV), a low Tafel slope (118 mV/dec), and long-term operational stability. These results demonstrated that the optimized FMO 55 /GO 45 composite is a potential candidate for dual applications such as pharmaceutical pollutant degradation and green hydrogen production, thereby bridging environmental remediation and renewable energy.