Construction of energy storage heterojunction and enhancement mechanism of dark and full-spectrum energy storage piezoelectric catalysis

• Energy storage heterojunction are prepared by piezoelectric and pyroelectric effect hydrothermal heterogeneous nucleation crystallization. • The charge stored in the heterojunction is enhanced by intrinsically polarized electric field and built-in electric field at interface. • Mechanical stress applied in the dark releases the stored charge to form high-energy radicals for rapid degradation of pollutants. • The heterojunction has dark-all-weather energy storage piezoelectric, piezoelectric photo, and piezoelectric catalysis capabilities. BiOBr/BiO(IO 3 ) 1-x-y (I 3 ) x I y energy storage heterojunction crystals are prepared by heterophase nucleation hydrothermal crystallization using piezoelectric and pyroelectric effects. Charge migration and drift formed by piezoelectric and pyroelectricity are stored into BiO(IO 3 ) 1-x-y (I 3 ) x I y and BiOBr crystals, storing 91.55 and 127.08 μmol⋅g −1 of electrons and holes. The formation of the built-in electric field at the interface enhances the polarization electric field of the energy storage heterojunction, and its piezoelectric d 33 value increases to 3.68 nm⋅V −1 . FEM simulations verify that the heterojunction interface to the crystal generates a piezoelectric potential difference and reverse piezoelectric current, charge migration and drift storage to the crystal. Applying mechanical stress under darkness the heterojunction can release the stored charge to form high-energy radicals and form piezoelectric charges to degrade pollutants, which has good dark cycle stability, dark broad-spectrum degradation and dark catalytic ability to be repairable. The stored charge piezoelectric photocatalysis, piezoelectric photocatalysis and piezoelectric catalytic synergy of heterojunctions under simulated solar/near-infrared light resulted in the formation of piezoelectric high-energy thermo radicals h + , ⋅OH, ⋅O 2 – , and 1 O 2 for the rapid degradation of pollutants. The present work provides new ideas for the structural design of piezoelectric crystals to build energy storage heterojunction catalysts and to realize efficient dark-full-spectrum catalytic applications.