Macroscopic Polarization Enhancement Promoting Photo‐ and Piezoelectric‐Induced Charge Separation and Molecular Oxygen Activation

Efficient photo‐ and piezoelectric‐induced molecular oxygen activation are both achieved by macroscopic polarization enhancement on a noncentrosymmetric piezoelectric semiconductor BiOIO 3 . The replacement of V 5+ ions for I 5+ in IO 3 polyhedra gives rise to strengthened macroscopic polarization of BiOIO 3 , which facilitates the charge separation in the photocatalytic and piezoelectric catalytic process, and renders largely promoted photo‐ and piezoelectric induced reactive oxygen species (ROS) evolution, such as superoxide radicals ( . O 2 − ) and hydroxyl radicals ( . OH). This work advances piezoelectricity as a new route to efficient ROS generation, and also discloses macroscopic polarization engineering on improvement of multi‐responsive catalysis.