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.