Simple and low-cost synthesis of tin ferrite decorated on graphitic carbon nitride for enhanced photodegradation of Rhodamine B and photoproduction of hydrogen peroxide

In this study, tin ferrite (SFO) was coupled with graphitic carbon nitride (CN) to construct SFOCN heterojunction photocatalysts for simultaneous Rhodamine B (RhB) degradation and hydrogen peroxide (H 2 O 2 ) photoproduction. The structural, morphological, and optical properties of the composites were investigated by XRD, VSM, SEM, EDX, XPS, and UV−Vis spectroscopy. Electrochemical analyses, including EIS, Mott−Schottky, and photocurrent response were employed to evaluate charge transfer characteristics. The SFOCN composites exhibited enhanced photocatalytic performance compared with pristine CN and SFO. The 10% SFO decorated CN (10SFOCN) composite achieved the highest RhB removal efficiency and H 2 O 2 yield, attributed to efficient interfacial charge transfer and reduced recombination. Radical scavenger experiments confirmed that •O 2 − played a dominant role, while •OH and h + contributed to a lesser extent. UV−Vis and Mott−Schottky analyses indicated a direct Z-scheme heterojunction between SFO and CN, which enables strong redox potentials to be retained. The photocatalyst also showed good recyclability and structural stability over repeated cycles. These results demonstrate that SFOCN heterojunctions are effective multifunctional photocatalysts, offering potential for the dual application of wastewater treatment and green H 2 O 2 production.