Analysis of the Piezoelectric Properties of Aligned Multi-Walled Carbon Nanotubes

Marina V Il’Ina,Nikolay N Rudyk,Oleg I Il’In,Oleg A Ageev,Alexander A Fedotov,Olga I Osotova

doi:10.3390/nano11112912

Marina V Il’Ina, Nikolay N Rudyk + Show 4 more

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https://doi.org/10.3390/nano11112912

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Journal: Nanomaterials	Publication Date: Oct 30, 2021
Citations: 10	License type: CC BY 4.0

Affiliation: Southern Federal University

Abstract

Recent studies reveal that carbon nanostructures show anomalous piezoelectric properties when the central symmetry of their structure is violated. Particular focus is given to carbon nanotubes (CNTs) with initial significant curvature of the graphene sheet surface, which leads to an asymmetric redistribution of the electron density. This paper presents the results of studies on the piezoelectric properties of aligned multi-walled CNTs. An original technique for evaluating the effective piezoelectric coefficient of CNTs is presented. For the first time, in this study, we investigate the influence of the growth temperature and thickness of the catalytic Ni layer on the value of the piezoelectric coefficient of CNTs. We establish the relationship between the effective piezoelectric coefficient of CNTs and their defectiveness and diameter, which determines the curvature of the graphene sheet surface. The calculated values of the effective piezoelectric coefficient of CNTs are shown to be between 0.019 and 0.413 C/m2, depending on the degree of their defectiveness and diameter.

Highlights

This paper presents the results of studies of the structure and piezoelectric properties of multi-walled carbon nanotubes grown by plasma chemical vapor deposition (PECVD)
We studied the structure and piezoelectric properties of multi-walled carbon nanotubes grown at different temperatures and thicknesses of the catalytic Ni layer
It was shown that carbon nanotubes grown using the PECVD method have a sufficiently high defectiveness due to the presence of bamboo-like structural defects and a catalytic center at the top of CNTs, which can be the source of their anomalous piezoelectric properties

Summary

Introduction

Due to high mechanical strength and elasticity, much attention in this direction has been attracted by carbon nanostructures subjected to various modifications [2,15,16,17,18,19,20,21] It has been experimentally and theoretically proven that a graphene sheet demonstrates surface piezoelectricity and flexoelectricity when non-centrosymmetric pores are formed in it [19,22], when creating a bending moment and biaxial strain [9,15,17], and through the selective surface adsorption of atoms [2,16,19,23]. We can observe an active use of the flexo- and piezoelectric properties of carbon nanostructures in order to create promising elements of nanoelectromechanical systems (nanogenerators, sensors, actuators, etc.) [15,24,25,26,27,28]

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Conclusion