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Progress in Flexible Piezoelectric Sensors and Piezocatalyst

April 19, 2021      Author:

China’s fight against the COVID-19 has achieved important temporary victories. Behind the production and supply of medical supplies, such as masks, ventilators, and ultrasonic medical equipment, there are countless new materials that play their respective roles, and piezoelectric ceramic materials is one of them.

Piezoelectric materials have an inherent mechanical-electrical coupling effect, which can produce mechanical deformation under the action of an electric field, and can also produce charges on both ends of the material under the action of mechanical deformation. Piezoelectric materials have been widely used in sensors, actuators and transducers.

Recently, Professor Guo Yiping’s research team from the School of Materials Science and Engineering of Shanghai Jiao Tong University made new progress in this field. They discovered that since low Curie temperature piezoelectric materials have a small energy barrier for spontaneous polarization deflection at room temperature, the polarization of flexible or nano-piezoelectric materials can be significantly deflected under very small action. This indicates that it has important application prospects in the fields of energy and environment, flexible wearable devices, and life sciences. They took the low Curie temperature piezoelectric material BaTi1-xSnxO3 (BTS) as the research object, and made a series of breakthroughs in the research of piezocatalyst and flexible piezoelectric sensing.

Figure 1 Low Curie temperature material BTS is used in piezoelectric nanogenerator and piezocatalyst

 

 

Relevant research findings have been published in internationally renowned journals, with one being published in Nano Energy under the title “Highly-efficient piezocatalytic performance of nanocrystalline BaTi0.89Sn0.11O3 catalyst with Tc near room temperature” with Shanghai Jiao Tong University as the first affiliation. SJTU postgraduate Zhao Qi and Ph.D. student Xiao Hongyuan are the co-first authors of the paper, and Professor Guo Yiping is the corresponding author. Another research article titled “Superflexible and lead-free piezoelectric nanogenerator as a highly sensitive self-powered sensor for human motion monitoring” has been accepted by Nano Micro Letters. SJTU postgraduate student Di Yu is the first author, and Professor Guo Yiping is the corresponding author.

Professor Guo Yiping’s research team has been committed to the basic and applied research of ferroelectric materials, and has undertaken a number of national, local and industry-related research projects. Related work was funded by the National Natural Science Foundation of China Key Project (52032012) and Shanghai Municipal Science and Technology Commission Key Basic Research Project (No. 20JC1415000).

 

Author: Zhao Qi, Yu Di

Source: School of Materials Science and Engineering, SJTU

Translated by Fu Jing

Proofread by Xiao Yangning, Fu Yuhe

 

 

ABSTRACT:

 

Inducing changes in polarization of a ferroelectric material by applied stress is recently regarded as a fascinating approach to achieve piezocatalysis in case of both dye degradation and H2 generation. The polarization-driven ferroelectrics are expected to reveal superior performance near Curie temperature (Tc) due to the maximum polarization change, but lack experimental proof. In this work, BaTi0.89Sn0.11O3 (BTS) with high piezoelectric coefficient and low Tc is taken as an example for materials of this kind. BTS nanoparticles with multiple phase coexistence and low Tc ~ 40 °C were prepared and used for dyes degradation and hydrogen generation. In-situ piezoresponse scanning force microscopy revealed a much-enhanced piezoelectric response near Tc, resulting in a highly-active piezocatalyst. The Rhodamine B (RhB) and Methyl orange (MO) could be decomposed within 15 min and 60 min, respectively. Superior H2 generation rates of 141.1 and 360.2 μmol g1 h1 were observed for BTS and BTS@Ag nanoparticles under ultrasonic irradiation at 15 °C. Furthermore, a highly-efficient pyrocatalytic performance with BTS nanoparticles was also found under cold–hot cycle excitation near Tc. This work demonstrates an efficient and low-cost strategy for water remediation via employing low Tc ferroelectrics by harvesting vibration or thermal energy from the surroundings.