Ferroelectric domain formation and photocatalytic activity on porous alkali niobate piezoelectric ceramics

Abstract

Present study showed synthesis of novel type of porous alkali niobate piezoelectric ceramics, and the formation of domains and photocatalytic activity for the porous piezoelectric ceramics were investigated while comparing with dense ceramics to confirm enhancement of domain orientation and photocatalytic activity around pores. Porous Li 0.06 Na 0.47 K 0.47 NbO 3 piezoelectric ceramics were synthesized by a template method using polymethylmethacrylate as a pore former agent. Uniform pores with 6¯m in diameter were dispersed in the porous ceramics. Porous ceramics synthesized with 10 vol % of the pore former agent showed piezoelectric voltage coefficient, 29 mVm/N, which is same as that of the dense ceramics. Smaller striped domains formed at an edge of pores on the porous ceramics, indicating that orientation of domains was promoted by electric field concentration around the pores. Through photoreduction reaction of Ag + ion, local precipitation of Ag was shown around the pores on the poled porous ceramics, whereas Ag was located over an entire surface of unpoled porous ceramics. Highest photocatalytic activity was shown for the poled porous ceramics in photodecomposition test of methylene blue. These results clearly indicated photocatalytic activity was enhanced on ferroelectric domains around pores of porous piezoelectric ceramics.

Aligned Porous Structure of (Ba,Ca)(Ti,Zr)O3 Piezoelectric Ceramics for Enhanced Catalytic Activity

“…The electric field is concentrated in the pore region with a low permittivity, which modulates the total polarization of the composite. [ 12 ]…”

“…The electric field is concentrated in the pore region with a low permittivity, which modulates the total polarization of the composite. [12] Figure 6 shows the longitudinal (d 33 ), transverse (d 31 ), and hydrostatic (d h ) piezoelectric charge coefficients of A-BCTZ and B-BCTZ. The relationship between the three coefficients is given by Equation (3).…”

“…The authors confirmed that ferroelectric domain orientation under applied electric fields was more active in porous ceramics than in dense ceramics, as well‐ordered stripe domain patterns were observed frequently in porous ceramics compared to dense ceramics. [ 12 ]…”

“…The authors confirmed that ferroelectric domain orientation under applied electric fields was more active in porous ceramics than in dense ceramics, as well-ordered stripe domain patterns were observed frequently in porous ceramics compared to dense ceramics. [12] Recently, piezoelectric-based catalysis has attracted significant attention as a new approach for inducing chemical reaction or enhancing photocatalytic activity. In piezoelectric catalysts, electrical surface charges can be induced by mechanical vibrations, and the charges can trigger redox reaction at the piezoelectric material-solution interface.…”

Pulse-Poled Porous BaTiO3 Ceramic for Piezocatalysis Applications

“…where denotes elastic compliance and represent contant factor. By introducing pores, generally increases 40 , decreasing dielectric constant ( 33) with further decrease in piezoelectric component generally bestowed more to reduce the piezoelectric coe cient (d 33 ) 41 .…”