Some studies have evaluated the photocatalytic activity of NBT in its pure form and heterojunctions for the degradation of organic dyes and H 2 generation by water splitting.
Its high electrical conductivity facilitates the migration of charge carriers, which makes it suitable for photocatalytic applications. (Na 0.5Bi 0.5)TiO 3 (NBT) is a lead-free perovskite of rhombohedral ( R3c) symmetry structure with promising piezoelectric properties. Some compositions have recently attracted interest for applications in piezoelectric energy harvesting, biopiezoceramics, environmental remediation, , among others. Perovskite ceramics (ABO 3) are multifunctional materials that are extensively studied for a large variety of applications mostly related to coatings, that include sensors, transducers, and actuators, ferroelectric memories, biosensors, among others. The heterojunction showed a direct band gap of 1.93 eV, which makes the NBT + flame spray process an excellent combination to couple visible light photoactive NBT + TiO 2 heterojunctions. Rapid solidification and high temperature of the flame spray process allowed to couple a heterojunction composed by NBT with small amounts of TiO 2 in both, anatase and rutile phases. NBT powder was fed into a flame spray gun and a thick coating of approx. NBT Perovskite was confirmed by XRD in the synthesized powders and sintered microspheres. NBT spray-dried agglomerates showed predominantly dense spheres with D 50 sizes in the range of 17–55 μm. NBT microspheres with size distribution described by D 10 = 25 μm and D 90 = 83 μm were prepared in a design of experiments using a two-fluid nozzle spray dryer equipment varying nozzle size, atomizing pressure, feeding rate of the spray drying equipment, and the solid content (vol%) of the slurry formulation. The effect of spray drying and sintering parameters on the characteristics of NBT microspheres are presented and discussed. The spray drying process and sintering treatments to produce NBT microspheres were optimized to obtain a size distribution suitable to be used as a feedstock for flame spray deposition. NBT powder was synthesized and processed by mixed oxides solid state reaction and milling. In this work, visible-light photoactive thermally sprayed coatings deposited from spray-dried NBT microspheres are reported. (Na 0.5Bi 0.5)TiO 3 (NBT) ceramics are candidates to be used as coarse coatings in several applications including environmental remediation, alternative energies, electromechanical devices, etc.