Multifunctional PVDF/SrTiO ₃ /PEDOT:PSS Ternary Nanocomposite for Energy‐Harvesting and Piezo‐Photocatalytic Applications

In this study, a lead‐free ternary poly(vinylidene fluoride) (PVDF)/strontium titanate (SrTiO ₃ )/poly(3,4‐ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) nanocomposite was developed to enhance piezoelectric and piezo‐photocatalytic performance. SrTiO ₃ nanoparticles (NPs) were synthesized via an autocombustion route and incorporated with PEDOT:PSS into the PVDF matrix, utilizing the solution‐casting method. Structural and spectroscopic analyses confirmed the successful formation of cubic‐phase SrTiO ₃ NPs and their uniform incorporation within the polymer matrix. The incorporation of SrTiO ₃ NPs and PEDOT:PSS significantly promoted electroactive phase formation in PVDF, yielding an electroactive phase content of 97.74% for the optimized composite. Complex impedance spectroscopy revealed enhanced interfacial polarization and improved dielectric behavior. Consequently, the optimized nanocomposite exhibited a high dielectric constant ε ′ ≈ 101.26 at 40 Hz frequency. The corresponding piezoelectric nanogenerator delivered an open‐circuit voltage of 45.50 ± 0.58 V and a maximum power density of 51.76 ± 1.33 μW cm ⁻² under periodic mechanical excitation. Furthermore, the optimized composite demonstrated enhanced piezo‐photocatalytic degradation of methylene blue dye, attributed to efficient charge separation induced by the piezoelectric potential under simultaneous mechanical and light stimulation.