A comprehensive review on the state-of-the-art of piezoelectric energy harvesting

The accumulation of various contaminants in air, soil and water is threatening the natural environment. The remediation of the environmental contaminations is today an urge. Among the remediation methods employed, advanced oxidation processes (AOPs) are a class of techniques based on the in situ generation of highly reactive and oxidizing radical species which can destroy most of the organic pollutants. AOPs driven by light are found to be the most popular for wastewater treatment due to the abundance of solar light in some regions. The removal of organic contaminants using semiconductor-based photocatalysts has been extensively investigated. However, low charge carrier mobility and rapid electron-hole pair recombination are the common problems that limit the semiconductor-based photocatalysis. Although a large number of alternative systems have been investigated, electron–hole pair separation is still too low in photocatalytic systems. A new concept was introduced recently in which the built-in electric field by ferroelectric, pyroelectric and piezoelectric effects in photocatalytic particles was exploited to enhance the separation of photoinduced charge carriers. Among these new systems that are still under investigation, the use of piezoelectric materials in the photodegradation of pollutants recently drew a lot of attention for environmental remediation. Due to the non-centrosymmetric nature, the piezoelectric materials demonstrate unique catalytic properties as a result of the creation of the built-in electric field by the dipole polarization. This latter provides a driving force for the transport of the photoinduced charge carriers enabling their separation. This review covers the use of piezoelectric materials in photocatalysis and catalysis, especially piezoelectric-catalysis, for environmental remediation. The paper details the fundamentals and basic properties of ferroelectric, pyroelectric and piezoelectric materials. The effect of the built-in electric field in these materials on the photocatalysis/catalysis charge carrier separation is discussed. Possible applications of piezoelectric materials in environmental remediation are reviewed and discussed taking into account several different aspects such as the kinetics of the degradation of the organic pollutants and water splitting. Finally, the current research trends and future prospects of piezocatalysis and piezophotocatalysis are discussed.

Piezoelectric materials for catalytic/photocatalytic removal of pollutants: Recent advances and outlook

Advances in Piezoelectric Polymer Composites for Energy Harvesting Applications: A Systematic Review

The goal of this paper is to review current methods of energy harvesting, while focusing on piezoelectric energy harvesting The piezoelectric energy harvesting technique is based on the materials' property of generating an electric field when a mechanical force is applied This phenomenon is known as the direct piezoelectric effect Piezoelectric transducers can be of different shapes and materials, making them suitable for a multitude of applications To optimize the use of piezoelectric devices in applications, a model is needed to observe the behavior in the time and frequency domain In addition to different aspects of piezoelectric modeling, this paper also presents several circuits used to maximize the energy harvested

/pdf/piezoelectric-energy-harvesting-solutions-a-review-449lsu70t1.pdf

Piezoelectric Energy Harvesting Solutions: A Review.

Piezoelectric materials and devices have drawn extensive attention for energy harvesting due to their excellent electromechanical conversion properties. With increasing concerns about environmental problems in traditional lead-based piezoelectric materials, it is imperative to develop lead-free piezoelectric alternatives. This paper is intended to give a brief review on the most recent advances in both inorganic (with an emphasis on piezoelectric ceramics and ZnO nanostructures) and organic (i.e. polyvinylidene difluoride (PVDF) and its copolymers and their composites, and biopolymers) lead-free piezoelectric materials. State-of-the-art piezoelectric devices, namely, nanogenerators, sensors, and transducers, are also introduced with detailed examples. Finally, the challenges and perspectives of lead-free piezoelectric materials and devices are given.

An overview of lead-free piezoelectric materials and devices

Smart materials, which exhibit piezoelectricity, find an eclectic range of applications in the industry. The direct piezoelectric effect has been widely used in sensor design, and the inverse piezoelectric effect has been applied in actuator design. Ever since 1954, PZT and BaTiO3 were widely used for sensor and actuator applications despite their toxicity, brittleness, inflexibility, etc. With the discovery of PVDF in 1969, followed by development of copolymers, a flexible, easy to process, nontoxic, high density alternate with high piezoelectric voltage coefficient was available. In the past 20 years, heterostructural materials like polymer ceramic composites, have received lot of attention, since these materials combine the excellent pyroelectric and piezoelectric properties of ceramics with the flexibility, processing facility, and strength of the polymers resulting in relatively high dielectric permittivity and breakdown strength, which are not attainable in a single phase piezoelectric material. The current review article is an attempt to provide a compendium of all the work carried out with reference to PVDF-PZT composites. The review article evaluates the effect of grain size, content and other factors under the purview of dielectric and piezoelectric properties while evaluating the sensitivity of the material for sensor application. POLYM. ENG. SCI., 55:1589–1616, 2015. © 2015 Society of Plastics Engineers

Rashmi P.N

Papers

Dielectric and piezoelectric properties of PVDF/PZT composites: A review