Ferroelectric KNbO₃nanofibers: synthesis, characterization and their application as a humidity nanosensor

Abstract

By virtue of its non-toxicity, high T c, and non-linear optical and ferroelectric properties, one-dimensional (1D) potassium niobate (KNbO3) may enable the development of numerous nanoscale devices. Despite the progress in 1D perovskite materials, preparing high aspect ratio KNbO3 nanostructures is still a concern. This report presents the successful synthesis of ultra-long KNbO3 nanofibers using a simple sol-gel assisted far-field electrospinning process. At optimized conditions, centimeters long, orthorhombic KNbO3 nanofibers with an average diameter of 100 nm have been obtained. The nanofibers are composed of uniform grains densely stacked along the direction of the nanofiber axis. Due to large surface-volume ratio, a high sensitive humidity nanosensor based on KNbO3 nanofibers displaying a logarithmic-linear dependence behavior of the conductance with the relative humidity (RH) was demonstrated. The conductance increases dramatically from 10(-10) ℧ to 10(-6) ℧ while RH varies from 15% to 95% at room temperature. In addition, the nanosensor exhibits excellent sensing performance, including ultrafast response (≤2 s) and recovery times (≤10 s), good linearity and reproducibility. Furthermore, the change in ferroelectric coercivity with respect to the RH and its effect in the sensing behavior were unveiled. This work could enable broad applications in the fields of environmental sensing and nano-electrical-mechanical systems.

Recent Advances in Ferroelectric Nanosensors: Toward Sensitive Detection of Gas, Mechanothermal Signals, and Radiation

“…An electric current response of SbSI nanowires to humidity changes was found to be exponential [33,35]. A similar behavior was observed for ferroelectric potassium niobate (KNbO 3 ) nanofibers by Ganeshkumar et al [59]. In this work, highquality ferroelectric KNbO 3 nanofibers were synthesized via the electrospinning method.…”

“…Then, a fabricated nanomaterial was used for fast and accurate humidity sensing, displaying a logarithmic-linear dependence behavior of an electric conductance with relative humidity. Similar to [35], mobile protons were found to be responsible for a strong increase in electrical conductivity due to water physisorption on the grain boundaries and flat surfaces of potassium niobate [59]. Nanosensors based on KNbO 3 nanofibers exhibited [58].…”

Applications of Nanotechnology in Plant Growth and Crop Protection: A Review

“…Accordingly, multiwalled carbon nanotubes (MWCNTs) are also competent in plant growth study by regulation of hormones, such as auxin which may help scientists to explore how plant roots are acclimatized to their environment, particularly to marginal soils [134]. Ganeshkumar et al [135] demonstrated that one dimensional potassium niobate (KNbO 3 ) nanofibers have great potential to sensing the humidity due to their large surface-volume ratio. The KNbO 3 nanofiber-based humidity nanosensors display a logarithmic–linear dependence behavior of the conductance with the relative humidity within two second, where the conductance increases from 10 −10 ℧ to 10 −6 ℧ for a relative humidity varying from 15% to 95% at room temperature.…”

Nanomaterials for Agricultural and Ecological Defense Applications: Active Agents and Sensors

“…Wang et al detected pathogenic fungus infestation in oil seeds by measuring salicylic acid levels with a gold electrode nanosensor (Wang et al, 2010). Ganeshkumar et al used potassium niobate (KNbO 3 ) nanofibers with a distinctive one‐dimensional morphology for sensing humidity (Ganeshkumar et al, 2016). The KbNO 3 nanofibers leveraged their substantive surface–volume ratio in manifesting a logarithmic–linear dependence behavior of conductance with relative humidity (Ganeshkumar et al, 2016).…”