Development of a GaN–P3MTH–PID nanocomposite platform for electrochemical, photocatalytic, and super capacitor applications

This investigation reports the fabrication and comprehensive functional evaluation of a newly engineered hybrid nanocomposite composed of gallium nitride (GaN) integrated with a poly(3-methylthiophene)-co-poly(indole) (P3MTH–PID) copolymer, synthesized via a straightforward chemical oxidative polymerization route. GaN nanoparticles were prepared using a supercritical ammonia method and subsequently combined with P3MTH–PID nanofibers to form a uniform hybrid structure. Structural and surface analyses confirmed robust π–π stacking interactions between the GaN scaffold and the P3MTH–PID copolymer matrix, which facilitated efficient charge delocalization and ensured homogeneous nanofiber distribution across the GaN interface. The hybrid material exhibited remarkable electrocatalytic sensitivity toward albendazole (ABZ), as demonstrated by differential pulse voltammetry (DPV), achieving a detection limit (DL) of 1.372 × 10⁻⁸ M µA⁻¹ and a quantification limit (QL) of 4.352 × 10⁻⁸ M µA⁻¹. Furthermore, the hybrid displayed excellent photocatalytic performance, enabling complete discoloration of methylene blue (MB) within 30 minutes under UV–visible irradiation, with a kinetic rate constant of 78.66 × 10⁻² min⁻¹. Beyond sensing and photocatalysis, the GaN–P3MTH–PID hybrid also showed significant promise in energy storage applications. In a three-electrode configuration, it delivered a high specific capacitance of 294.25 F g⁻¹ at 1 A g⁻¹, while a symmetric supercapacitor device (2 × 2 cm²) assembled from the same material exhibited comparable capacitance and excellent long-term cycling stability. Collectively, these findings highlight that the GaN–P3MTH–PID hybrid integrates superior electrochemical, photocatalytic, and sensing functionalities with strong stability and biocompatibility, making it a highly versatile candidate for sustainable and multifunctional energy storage and environmental applications.