Enhanced triboelectric degradation of organics by regulating oxygen vacancies and constructing heterojunctions

In contrast to conventional oxidation techniques, tribocatalysis degradation of organics has gained much attention in recent years due to its mild requirement and low amount of energy needed. Therefore, we prepared Ba1.4Sr3.6NdNb7Ti3O30 (BSNNT) ferroelectric nanopowder by a solid-phase synthesis method and further investigated the effects of oxygen vacancies and heterojunctions on the tribocatalysis effect. The results showed that the introduction of oxygen vacancies not only reduced the valence electron potential required for the reaction but also greatly reduced the combination of electrons and holes. The efficiency of degradation of RhB by oxygen vacancy-rich BSNNT can reach 97 % after 2 h. Furthermore, the BSNNT-N2/CN-2 (BN2/CN-2) Z-type heterojunction achieves a tribocatalytic enhancement with 98.2 % RhB degradation in 2 h, which is attributed to the built-in electric field of ferroelectric materials and the appropriate band gap matching between g-C3N4 (CN) and BSNNT-N2 (BN2), facilitating the electron and hole transport paths between the semiconductor and ferroelectric materials. Therefore, new approaches to enhance tribocatalytic degradation of dye wastewater by increasing oxygen vacancies and constructing heterojunctions were proposed and examined based on tungsten bronze ferroelectric materials.