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Photocatalysts for oxidation reactions are crucial for a wide variety of industrial activities. Here, we describe a framework consisting of silver nanomaterials atop Mg-doped lithium niobate. This substrate under white light irradiation is demonstrated to support the oxidation of compounds, such as p-aminothiophenol, through the activation of charge transfer processes. This study highlights the use of doped lithium niobate materials as semiconductor platforms for plasmonic photocatalysis. [ABSTRACT FROM AUTHOR]

In this study, we integrate plasmonic metal nanomaterials with a piezoelectric polyvinylidene fluoride (PVDF) polymer and lithium niobate (LiNbO3) based composite to form an all-solid-state flexible self-energized sensor. We demonstrate that following the application of a load, the film enhances the surface-enhanced Raman spectroscopy (SERS) signal of an analyte molecule up to 14 times. The piezoelectric β-phase of PVDF in the film is optimized through the introduction of multi-walled carbon nanotubes and post-fabrication UV irradiation annealing. Additionally, the SERS signal enhancement can be further increased by the application of in situ UV light irradiation of the sample, resulting in the generation of photoexcited electrons from LiNbO3 microparticles introduced into the composite. Both the application of a mechanical displacement and the UV light-induced charge generation result in an improved charge transfer between the film and an analyte molecule. The piezoelectric PVDF/LiNbO3 film has been shown to be a suitable SERS platform for the detection of important biological molecules, demonstrating the potential of the substrate for fast on-site detection applications. [ABSTRACT FROM AUTHOR]

Enabling an understanding of the optical properties of functional inorganic–organic materials is crucial for driving development in many areas such as medicine and optoelectronics. In particular the use of two-dimensional materials such as hexagonal boron nitride has been recently investigated for the fabrication of nanohybrid composites due to the unique properties of the material. Here we report the use of boron nitride/silver nanoparticle (BN/AgNP) composite templates as an effective substrate for controlling the fluorescence emission of adsorbed organic molecules through applying external electric fields in the range of 0 to 3 × 104 V/m. We report fluorescence quenching in the field and enhancement of fluorescence signal intensity of J-aggregate porphyrins up to 20 min following removal of the applied voltage. We propose that the observed enhancement can be attributed to charge release upon switching off the field due to capacitance effects associated with the BN/AgNP substrate. [ABSTRACT FROM AUTHOR]

Piezoelectric diphenylalanine peptide nanotubes (PNTs) have recently been demonstrated in energy harvesting applications, typically based on vertically aligned PNTs that generate charge when pressed. In this work, we use a wettability difference and an applied electric field to align PNTs and PNT-based composites on flexible substrates. Open-circuit voltages and short-circuit currents exceeding 6 V and 60 nA, respectively, are achieved by bending the substrate, opening up the use of horizontally aligned PNTs as flexible energy harvesting substrates. [ABSTRACT FROM AUTHOR]

Iron-core electromagnets are widely used as applied-field switches in high-temperature superconducting (HTS) flux pumps. It was recently reported that the critical current ( I c ) of the HTS wire is suppressed by up to 45% in the air gap of the iron core. Here, it is reported that the self-field I c of a single tape (unifilar) is suppressed from 357 A to 195 A while in the air gap of an iron core, agreeing closely with the previous study. This is extended by showing that the I c response to a perpendicular magnetic field is asymmetric, with a peak I c of 249 A found to be at 0.16 T of applied magnetic field. This effect can be eliminated using an anti-parallel current configuration (bifilar), which is shown experimentally to recover close to the no-core self-field I c of 357 A with no observed asymmetry. The results of both types of switch configurations are closely replicated in finite-element modelling using COMSOL Multiphysics®. This is caused by the asymmetric interaction between the self-induced magnetic field of the HTS switch element and the magnetic circuit of the iron-core electromagnet. [ABSTRACT FROM AUTHOR]