High‐Performance Flexible Piezo–Tribo Hybrid Nanogenerator Based on MoS₂@ZnO‐Assisted β‐Phase‐Stabilized Poly(Vinylidene Fluoride) Nanocomposite

Abstract

In order to efficaciously harvest these mechanical/bio-mechanical energies, piezoelectric and triboelectric nanogenerators (PENGs and TENGs) are frequently utilized owing to their admirable energy harvesting behaviour. Aside from PENGs, TENGs show a great potential in various applications like pressure, motion, and tactile sensors. [1][2][3][4] The principle of TENGs is based on electrostatic induction and contact electrification where by using frictional force electric charges are generated. The advantage of using TENGs is for its high output power density, high durability, wide choice of materials, and simple design. The contactseparation mode, lateral-sliding and freestanding mode are very well known techniques for enhancement of the TENG output performance. [5][6][7] Among these, contactseparation mode is more efficient for its easy fabrication and good output performance. [8,9] On the other hand in case of PENG the stacked layers don't come in contact with each other and thus, there is no friction between these layers, because the piezoelectric material or composite is stacked between two electrodes. Therefore PENGs are appropriate for powering biomedical devices, [10] micro/nano systems, [11] and wearable electronic devices. [12,13] Thus, from small-scale to large-scale applications, it is very useful to fabricate a device that shows multifunctional mechanism, i.e., piezoelectric as well as triboelectric mechanism for better result. [14] The fabrication of PENGs can be done with different kinds of materials like lead zirconate titanate (PZT), [15] ZnO, [16] BaTiO 3 , [17] and GaN [18] for their good piezoelectric properties. For the enchanting features and different types of potential applications, the twodimensional (2D) layered transition metal dichalcogenides (TMDs) attract a huge attention nowadays. [19,20] Molybdenum disulfide (MoS 2 ) is one such kind of TMDs that has superior, distinctive functional properties that includes high current-carrying capacity and large carrier mobility that come out with emerging applications. [21] MoS 2 has very interesting structure, with different crystal phases such as 1-layer hexagonal unit cell (1H), 2-layer hexagonal crystal cell (2H), and three-layer rhombohedral unit cell (3R). The monolayer MoS 2 (1H) has a fascinating property that can demonstrate piezoelectricity with piezoelectric coefficient (2.99 p.m. V À1 ) to in-plane d11. [22] With increasing the number of odd layer of MoS 2 , its piezoelectricity gradually decreases. [23] The noncentrosymmetric materials are very crucial for creating the mechanical stress that causes the dipole

Halide Tunablility Leads to Enhanced Biomechanical Energy Harvesting in Lead-Free Cs2SnX6-PVDF Composites

“…Nevertheless, we acknowledge that there is always a small amount of tribo-effect mixed in the output signal due to unavoidable contact (inadvertent rubbing or sliding motions leading to friction) when applying mechanical stress. Presently, we are not in a position to distinguish this due to the lack of geometry-specific instrumentation that can segregate the piezo signal from the tribo. , Notably, in one of the recent works, the authors have combined the two geometries and prepared a hybrid nanogenerator that utilizes the combined effect of both piezo- and triboelectric nanogenerators to achieve much higher voltage and output power. A consistent output voltage of ∼150 V is also achieved as the rectified DC output signal from the PCSI, as illustrated in Figure f.…”

Metal–Organic Framework–Derived ZnO‐Assisted β‐Phase‐Stabilized High‐Performance PVDF/ZnO‐PDMS/rGO Nanocomposites as Piezo–Tribo Hybrid Nanogenerator

“…[ 60 ] After calcination, these picks were disappeared and characteristic picks for ZnO were appeared at 2 θ ≈ 31.75°,34.41°, 36.19°, 47.45°, 56.48°, 62.93° corresponding to the plane of (100), (002), (101), (102), and (110), which matches with the JCPDS NO‐36‐1451. [ 61 ] This confirms the formation of hexagonal wurtzite ZnO. The average crystalline size of the ZnO nanoparticles was calculated by using the Debye Scherrer formula, where t is the crystallite size, β is the full width at half maximum of the diffraction peak, θ is the Bragg's angle in radians, and λ is the X‐ray wavelength (≈0.154 nm).…”

Innovative Synthesis of Zeolitic Imidazolate Framework by a Stovetop Kitchen Pressure Cook Pot for Triboelectric Nanogenerator

“…[ 32 ] MoS2@ZnO enhanced β‐phase Polyvinylidene fluoride (PVDF) nanocomposite‐based energy harvester is capable of harvesting energy from diverse mechanical and biological movements. [ 33 ] Patil et al designed Delonix regia flowers/PTFE‐structured TENG showcasing lighting up 210 LEDs and powering an electronic stopwatch. [ 34 ] PVDF/ZnO nanocomposites‐based TENG‐PENG hybrid device could generate a power density of 338 μW cm −2 as reported by Ojha et al [ 33 ] This confirms that TENG is effective as an energy harvester and can be utilized for various self‐powered applications.…”