• Surface modification of PZT with polydopamine (PZT@PDA) enhances interfacial interaction with PVDF, promoting the formation of the piezoelectric β phase.
• The β phase content increases with PZT@PDA loading, reaching a maximum of 28.09% at 5 wt.% PZT@PDA.
• PZT@PDA acts as a nucleating agent but also reduces overall crystallinity, while increasing interfacial polarization sites.
• The 5 wt.% PZT@PDA composite film exhibits superior electrical properties, with a dielectric constant of 8.61 and residual polarization of 0.6803 μC/cm².