Abstract[001]C‐Textured 0.55Pb(Ni1/3Nb2/3)O3–0.15PbZrO3–0.3PbTiO3 (PNN‐PZT) ceramics are prepared by the templated grain‐growth method using BaTiO3 (BT) platelet templates. Samples with different template contents are fabricated and compared in terms of texture fraction, microstructure, and piezoelectric, ferroelectric and dielectric properties. High piezoelectric performance (d33 = 1210 pC N−1, d33* = 1773 pm V−1 at 5 kV cm−1) and high figure of merit g33⋅d33 (21.92 × 10−12 m2 N−1) are achieved in the [001]C‐textured PNN‐PZT ceramic with 2 vol% BaTiO3 template, for which the texture fraction is 82%. In addition, domain structures of textured PNN‐PZT ceramics are observed and analyzed, which provide clues to the origin of the giant piezoelectric and electromechanical coupling properties of PNN‐PZT ceramics.
Piezoelectric ceramic devices, which utilize multifarious vibration modes to realize electromechanical coupling and energy conversions, are extensively used in high‐technological fields. However, the excitation of basic modes is mainly subjected to natural eigenfrequency of ceramic devices, which is related to the structure and material parameters. Herein, inspired by metamaterial theory, a programmable, 3D ordered structure with piezoceramic strain units (3D OSPSU) is developed to artificially generate basic modes in a broad frequency band other than only in narrow eigenfrequency. A (2 × 2 × 2) arrayed, co‐fired, multilayer 3D OSPSU is painstakingly designed and fabricated for generating basic modes, such as flexural, extension, shear, torsion, and even coupled modes at nonresonance. To validate the 3D OSPSU method, a five‐degree‐of‐freedom micro–nano actuating platform based on only one co‐fired multilayer ceramic is constructed. The proposed methodology provides a new paradigm for creating extraordinary material properties of piezoelectric ceramics and will inspire brand‐new piezoelectric device designs.
A WO3-x/TiO2-x nanotube array (NTA) heterojunction photoanode was strategically designed to improve photoelectrocatalytic (PEC) performance by establishing a synergistic vacancy-induced self-doping effect and localized surface plasmon resonance (LSPR) effect of metalloid non-stoichiometric tungsten suboxide. The WO3-x/TiO2-x NTA heterojunction photoanode was synthesized through a successive process of anodic oxidation to form TiO2 nanotube arrays, magnetron sputtering to deposit metalloid WO3-x, and post-hydrogen reduction to engender oxygen vacancy in TiO2-x as well as crystallization. On the merits of such a synergistic effect, WO3-x/TiO2-x shows higher light-harvesting ability, stronger photocurrent response, and resultant improved photoelectrocatalytic performance than the contrast of WO3-x/TiO2, WO3/TiO2 and TiO2, confirming the importance of oxygen vacancies in improving PEC performance. Theoretical calculation based on density functional theory was applied to investigate the electronic structural features of samples and reveal how the oxygen vacancy determines the optical property. The carrier density tuning mechanism and charge transfer model were considered to be associated with the synergistic effect of self-doping and metalloid LSPR effect in the WO3-x/TiO2-x NTA.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.