Synergizing piezoelectric and plasmonic modulation of Ag/BiFeO3 fibrous heterostructure toward boosted photoelectrochemical energy conversion

Highlights: • Electrospun BiFeO₃ nanofibers exhibited excellent piezoelectric properties. • Ag/BiFeO₃ fibrous heterostructures showed advanced piezo-photocatalytic activity. • Synergistic piezoelectric and plasmonic effect enabled efficient photo-induced charge separation. Coupling piezoelectric and plasmonic effect to tune the separation and migration of photogenerated charge carriers remains the key to improving the visible-light-driven photoelectrochemical energy conversion performance. Herein, we report the rational design of Ag/BiFeO₃ fibrous heterostructures (Ag/BFO) with the synergy of piezoelectric field and localized surface plasmon resonance (LSPR) modulation. Piezo-response force microscopy detection shows that the Ag2/BFO (AgNO₃ dosage: 2 mL) heterostructure has the optimal piezoelectric properties (29.3 pm at −7.53 V). As a demonstration, the degradation of methyl orange and methylene blue is used to evaluate the photoelectric conversion performance of the prepared samples. The results indicate that the ultrasonic-driven and visible-light-driven Ag2/BFO sample presents significantly enhanced activity, in which the piezoelectric field inside the BFO can further promote the directional migration and separation of photogenerated charge carriers induced by the LSPR effect of Ag nanoparticles. This work offers an intriguing solution toward the rational design of advanced materials targeting direct conversion of solar light into chemical energy.