Optical, dielectric and photoelectrochemical performances of the CeO₂/silicon nanowire system: Studying the silicon nanowire length effect on the photodegradation of rhodamine B

In this study, we explore the advanced optical and dielectric properties of cerium dioxide nanoparticles combined with silicon nanowire (CeO₂NP/SiNW) composites. Utilizing diffuse reflectance spectra (R(λ)), we extracted key parameters such as the extinction coefficient (k), refractive index (n), electrical conductivity (σ_elc), optical conductivity (σ_opt), and dissipation factor (tan δ) within the spectral range of 330–2000 nm. Capacitance measurements revealed a p-type conduction mechanism with a flat band potential (E_fb) of − 0.02 V. X-ray diffraction (XRD) analysis confirmed the cubic phase of the CeO₂NPs, while photoluminescence (PL) studies exhibited a broad emission peak at approximately 680 nm. The morphology of the CeO₂NP/SiNW composites was meticulously analyzed using scanning electron microscopy (SEM), focusing on variations due to different SiNW etching times. Critically, the impact of SiNW length on the photodegradation efficiency of Rhodamine B was evaluated, demonstrating a remarkable 100% degradation rate for nanowires with a length of 31.52 µm. This work underscores the importance of comprehensively studying the optical, dielectric, and photoelectrochemical properties to optimize the degradation of Rhodamine B.