Enhanced Photocatalysis by Synergistic Piezotronic Effect and Exciton–Plasmon Interaction Based on (Ag‐Ag₂S)/BaTiO₃ Heterostructures

Abstract Piezotronic and plasmonic effects are effective strategies to improve photocatalytic performance. Combining these two effects in one photocatalytic heterostructure is intriguing, but has yet to be reported. Here, a hybrid ternary structure ((silver‐silver sulfide)/barium titanate (Ag‐Ag 2 S)/BaTiO 3 ) is introduced, where the synergistic exciton–plasmon interaction in Ag‐Ag 2 S and Ag 2 S/BaTiO 3 heterojunction tuned by piezoelectric polarization can enhance the photon absorption and charge carrier separation to promote photocatalysis efficiency. The exciton–plasmon interaction in Ag‐Ag 2 S can amplify the plasmon resonance to the semiconductor region and enhance the light absorption of Ag 2 S. The piezoelectric polarization can tune the band structure of BaTiO 3 and then change the heterojunction between Ag 2 S/BaTiO 3 from Type I (i.e., straddling energy band alignments between BaTiO 3 and Ag 2 S) to Type II (i.e., Z‐scheme system between BaTiO 3 and Ag 2 S with a staggered energy band alignment), which can accelerate the separation of electron‐hole pairs. Using this hybrid material, a high methyl orange (MO) degradation rate up to 90% within 30 min is obtained, which is 20% higher than that of Ag/BaTiO 3 . The demonstrated hybrid material based on the synergistic piezotronic effect and exciton–plasmon interaction shows great promise in pollutant treatment with high efficiency.