[en] Highlights: • BZT-BCT fibers can scavenge low level mechanical energy to decompose organic dye. • The degradation comes from OH and O₂⁻ generated by the deformation of nanofibers. • The degradation efficiency can be greatly enhanced by decreasing fibers’ diameters. • Provide an effective, practical and low-cost method to decompose organic dye. A newly discovered nanometer material-mediated piezoelectrochemical (PZEC) for the direct conversion of mechanical energy to chemical energy has attracted increasing attention, for its great potential to be a green dye water decomposition technique. However, it is far from being a cost-effective and practical technique because only ultrasonic can be scavenged to decomposed organic pollutant in previous studies. Here, we prepared 0.5Ba(Zr_0.2Ti_0.8)O₃-0.5(Ba_0.7Ca_0.3)TiO₃ (BZT-BCT) piezoelectric fibers for the degradation of dye solution via slow stirring and studied the degradation mechanism. It provides a practical, green and low-cost method for decomposing organic dye by scavenging waste mechanical energy from the surrounding environment.

[en] Here, we report our study results of a flexible piezoelectric tensile strain sensor which is fabricated by synthesizing 0.5Ba (Zr_0.2Ti_0.8) O₃–0.5(Ba_0.7Ca_0.3) TiO₃ (0.5BZT–0.5BCT) nanofibers via an electrospinning process. Our nanofibers show an ultrahigh d₃₃ of 275 pm V⁻¹. 0.5BZT–0.5BCT nanofibers and MW-CNTs are dispersed in polydimethylsiloxane (PDMS) to fabricate a highly stretchable and flexible tensile sensor, and the multiple roles of the MW-CNTs are probed and demonstrated. This nanofiber-based piezoelectric tensile strain sensor shows great resolution and sensitivity under external mechanical deformation. It is suitable for applications in complex environments. (technical note)

[en] Superhydrophobic surface has aroused wide concern over the years due to its extensive application prospect. However, a simple, cost-effective and environmental friendly preparation method is still lacking. Here, we present an effective approach to prepare a superhydrophobic surface for long-term metal corrosion protection. Positively charged SiO₂ composite nanoparticles were successfully prepared by a simple and multiple ultrafiltration method firstly, after that the particles were sol-gel electrodeposited on steel to build micro-nano roughness surface, and then the surface was modified by cost-effective and fluorine-free chemical stearic acid with low energy surface. The results of wettability experiment show a strong repulsive force between the modified surfaces and water droplets, with static contact angles over 158°. The corrosion resistance and corrosion current density of the Al₂O₃@KH560@SiO₂ composite film assessed by the electrochemical impedance spectroscopy (EIS) and the polarization and neutral salt spray test indicate that the corrosion rate of the metal is reduced and the corrosion performance of the matrix is improved at the same time.

[en] Highlights: • Unique design of self-poled ferroelectric fibers with curving structure. • The curving strain gradient and ferroelectric effect is molded and calculated. • The stable self-poled fibers could resist external electric field and temperature. • Nanogenerator fabricated by self-poled fibers has outputs comparable to the poled one. Self-poling has been found in many two-dimensional epitaxial ferroelectric nanofilms originating from epitaxial growth clamping and has become a new research focus due to its potential applications in designing new types of ferroelectric devices. However, self-poling ferroelectrics based on internal strain gradients rather than external stimuli still do not exist. Here, we demonstrate a novel and unique design for one-dimensional structures and geometries in microscale with robust upward flexoelectric self-poling created by the application of electrospun ferroelectric fibers on a patterned substrate to introduce curving structure arises from the uneven substrate and confinement by other fibers in space. The fiber textile composed of these curving structures could resist external electric field and temperature, and can be fabricated into high performance poling-free flexible nanogenerators with outputs comparable to the poled ones. These results are conducive to providing a potential solution to the depolarization problem, to simplifying the technologies for manufacturing piezoelectric nanogenerators by avoiding the application of electric field for poling, and to providing extra freedom in controlling ferroelectric polarization and designing new types of devices.