Piezoelectric polarization of BiOCl via capturing mechanical energy for catalytic H2 evolution

Exploring a green and sustainable method for catalytic water splitting to hydrogen (H2) holds a great potential towards solving the looming global environment and energy crisis. Herein, a piezoelectric catalytic H2 evolution reaction (HER), using a sheet-like BiOCl as the catalyst, can convert mechanical energy into clean hydrogen energy. A high yield of HER (975.4 µmol g−1h−1) was reached by the ultrasound-based piezoelectric catalysis, exhibiting the excellent piezoelectric catalytic activity of as-synthesized BiOCl. Under mechanical vibration of ultrasound, sheet-like BiOCl would deform, inducing piezoelectric polarization and generation of abundant free polarized-electrons on the surface for redox reactions. BiOCl with continued ultrasonic vibration not only achieves durability HER, but also simultaneously utilizes electrons and holes to form reactive oxygen species (ROS) for a high-efficient degradation rate (98%) of organic antibiotic pollutants (sulfamethazine) removal in 120 min. This work provides a new idea for promoting environmental purification and developing clean hydrogen energy.