Fundamental and Technological Aspects of Transition Element Doped Leadfree Ferroelectrics for Novel Photo-Ferro/Piezocatalytic Application

Abstract

photocatalysis and photovoltaics because of their efficient ferroelectric polarization-driven carrier separation which in principle can lead to better photocatalytic activity compared to conventional semiconducting oxides. However, the efficiency reported so far for conventional ferroelectrics is still too low to be considered for practical application due to the wide band gap (>3eV) of these materials. The invention of visible light absorbing semiconducting ferroelectric oxide (1-x)KNbO3 -x(BaNi1/2Nb1/2O3-δ) (KBNNO) by Grinberg et al. augmented global research activity in the area of semiconducting ferroelectric. Significant improvement was observed in photovoltaic efficiency and photocurrent in those solid solutions. However, it is weak ferroelectric. Recently, (Ba,Ca)(Zr,Ti)O3 (BCZT) was studied extensively as lead-free piezoelectric material. The band gap tunability, the effect of particle size and the formation of heterostructure with other semiconducting oxides for improvement of photocatalytic properties of BCZT and KBNNO-based ceramics will be discussed in the presentation. Furthermore, the powder form of photocatalyst is being used conventionally, but the issue generated here is the secondary pollution which may be eliminated through highly porous (open/channel pore) spherical-shaped photocatalyst granules or open-celled foam which can be easily collected after the completion of photocatalysis process. In addition, fabrication, and characterization of BCZT composite granules/open-celled foam catalyst will be discussed in the presentation.