Three dimensional BaTiO3 piezoelectric ceramics coated with TiO2 nanoarray for high performance of piezo-photoelectric catalysis

Persistent organic pollution (POPS) with the feature of difficult to be degraded, highly toxic and global spread has become a challenge for the whole human beings. Recently, piezo-photoelectric catalysis is emerging as a promising way to degrade organic pollutions. In order to avoid the secondary pollution caused by the difficult recycling of powder catalyst, a three-dimensional barium titanate (BaTiO3, BT) scaffold is prepared by direct writing technique in this study, of which the surface is decorated by titanium oxide (TiO2, TO) nanowire arrays. Piezoelectric potential can be generated in the BT scaffold, especially in the direction parallel to the direct writing printing, and the piezoelectric electric field can effectively promote the separation of photo-generated carriers. This design of the structure can effectively produce a larger deformation compared with the bulk structure in the catalytic process, and it can also increase the contact area between the catalyzer and solution with enhanced reactive site. Due to the piezo-phototronic coupling effect, BT piezoelectric ceramic scaffold with TiO2 array exhibits an excellent dye degradation efficiency, of which the rate constant reaches approximately 0.109 min−1 for 100 mL of 10 mg/L of indigo carmine (IC) degradation. This work demonstrated that 3D piezoelectric ceramics by direct ink writing method shows a great potential in promoting the practical application of catalysis.