Construction of piezoelectric BaTiO3/MoS2 heterojunction for boosting piezo-activation of peroxymonosulfate

The rapid recombination of charge carriers in piezoelectric materials has always been the problem that limits their piezoelectric performance for removal of organic pollutants in water. Herein, we construct a piezoelectric BaTiO3/MoS2 (BTO/MS) that follows a type II heterojunction charge transfer system to inhibit the recombination of electron-hole (e‒-h+) pairs, which is beneficial to the activation of peroxymonosulfate (PMS) for the removal of antibiotic ornidazole (ORZ) pollutants. The optimal ratio of BTO/MS for ORZ degradation under the piezo/PMS process is 13.9, 3.6, 62.1 and 2.0 times higher than that of the BTO/piezo, MS/piezo, (BTO/MS)/PMS and (BTO/MS)/piezo processes, respectively. The high efficiency charge separation in the piezoelectric heterojunction of BTO/MS promotes the activation of PMS, resulting in the synergy of pizeocatalysis and PMS oxidation during the process of ORZ degradation. This study provides an idea for enhancing piezo-activation of PMS by constructing heterojunctions in piezoelectric materials.