Title: Characterization of Na0.5Bi0.5TiO3 prepared by hydrothermal method for photocatalytic applications

Abstract

Sodium bismuth titanate (Na0.5Bi0.5TiO3, NBT) ceramics have been prepared by using a simple hydrothermal method. Low temperature process of thermal treatment was conducted to obtain a highly dense morphology NBT, using high-purity oxides and carbonates as the initial precursors. The presence of well-crystallized NBT in the rhombohedral phase was also found at hydrothermal temperatures above 180°C. A concentration of at least 10 M NaOH and a reaction time of at least 24 hours were needed to attain maximum perovskite phase. Xray diffraction, Raman spectroscopy, Infrared spectroscopy, and SEM analysis confirm the structure, phase, morphology, and composition. NBT ceramics exhibit the typical characteristics of relaxor ferroelectrics, with a diffusion exponent γ of up to 1.5 to promote their applications in micro-electromechanical and energy harvesting systems. The photocatalytic properties of the hydroth- ermally synthesised powder were evaluated with respect to the degradation of meth- ylene blue (BM). Furthermore, the photocatalyst's stability is excellent. The article carefully discusses the detailed mechanism of photocatalysis.