High Thermoelectric Performance Related to PVDF Ferroelectric Domains in P-Type Flexible PVDF-BiSbTe Composite Film.

There is increasing demand to power Internet of Things devices using ambient energy sources. Flexible, low-temperature, organic/inorganic thermoelectric devices are a breakthrough next-generation approach to meet this challenge. However, these systems suffer from poor performance and expensive processing preventing wide application of the technology.

Origin of the switchable photocurrent direction in BiFeO thin films.

We report external bias driven switchable photocurrent (anodic and cathodic) in 2.3 eV indirect band gap perovskite (BiFeO) photoactive thin films. Depending on the applied bias our BiFeO films exhibit photocurrents more usually found in p- or n-type semiconductor photoelectrodes.

Enhancement of Thermoelectric Performance in BiSbTe Particulate Composites Including Ferroelectric BaTiO Nanodots.

An increasing number of studies have reported producing composite structures by combining thermoelectric and functional materials. However, combining energy filtering and ferroelectric polarization to enhance the dimensionless figure of merit thermoelectric remains elusive. Here we report a composite that contains nanostructured BaTiO embedded in a BiSbTe matrix.

High Efficiency Water Splitting using Ultrasound Coupled to a BaTiO Nanofluid.

To date, a number of studies have reported the use of vibrations coupled to ferroelectric materials for water splitting. However, producing a stable particle suspension for high efficiency and long-term stability remains a challenge. Here, the first report of the production of a nanofluidic BaTiO suspension containing a mixture of cubic and tetragonal phases that splits water under ultrasound is provided.

Ammonia Gas Sensor Response of a Vertical Zinc Oxide Nanorod-Gold Junction Diode at Room Temperature.

Conventional metal oxide semiconductor (MOS) gas sensors have been investigated for decades to protect our life and property. However, the traditional devices can hardly fulfill the requirements of our fast developing mobile society, because the high operating temperatures greatly limit their applications in battery-loaded portable systems that can only drive devices with low power consumption. As ammonia is gaining importance in the production and storage of hydrogen, there is an increasing demand for energy-efficient ammonia detectors.

Perceptions About Quality of Interpersonal Processes and Practice Activities in Youth Sport Are Interdependent.

Despite calls in the literature, little is known about how dimensions of a social and task nature relate to each other in school and out-of-school learning environments. This study explored whether interpersonal and task dimensions of the youth sport environment, as perceived by young people, are related, and, if so, how they are related. We used data from 310 adolescent sport participants from eastern Canada ( = 14.

Demonstration of Enhanced Piezo-Catalysis for Hydrogen Generation and Water Treatment at the Ferroelectric Curie Temperature.

Hydrogen can contribute significantly to the energy mix of the near future, as it is an attractive replacement for fossil fuels due to its high energy density and low greenhouse gas emission. A fascinating approach is to use the polarization change of a ferroelectric due to an applied stress or temperature change to achieve piezo- or pyro-catalysis for both H generation and wastewater treatment. We exploit low Curie temperature (T) ferroelectrics for polarization-driven electrochemical reactions, where the large changes in polarization and high activity of a ferroelectric near its T provides a novel avenue for such materials.

Role of Temperature and Growth Period in the Synthesis of Hydrothermally Grown TiO₂ Nanorods.

Highly uniformed, surfactant free and vertically oriented titanium-di-oxide (TiO₂) nanorods were grown on pre-treated fluorine doped tin oxide (FTO) using hydrothermal method through titanium tetra butoxide (Ti(OBu)₄) as titanium source. Three different temperatures 130 °C, 150 °C and 180 °C were followed to grow the nanorods at a fixed reaction time of 4 h. The prepared TiO₂ nanorods were annealed at the temperatures of 550 °C and 600 °C for 3 h.

Influence of ferroelectric dipole on the photocatalytic activity of heterostructured BaTiO/a-FeO.

Using BaTiO as a model ferroelectric material we investigated the influence of the ferroelectric dipole on the photocatalytic activity of a heterogeneous BaTiO/α-FeO photocatalyst. Two distinct BaTiO samples were used: BTO and BTO-A. The latter consists more ferroelectric tetragonal phase and thus stronger ferroelectricity.

Optimization of 3D ZnO brush-like nanorods for dye-sensitized solar cells.

In a dye-sensitized solar cell (DSSC) the amount of adsorbed dye on the photoanode surface is a key factor that must be maximized in order to obtain enhanced DSSC performance. In this study 3D ZnO nanostructures, named brush-like, are demonstrated as alternative photoanodes. In these structures, long ZnO nanorods are covered with a metal-organic precursor, known as a layered-hydroxide zinc salt (LHZS), which is subsequently converted to crystalline ZnO using two-step annealing.

Enhanced Photocatalytic Activity of Heterostructured Ferroelectric BaTiO/α-FeO and the Significance of Interface Morphology Control.

We have used a ferroelectric BaTiO substrate with a hematite (α-FeO) nanostructured surface to form a heterogeneous BaTiO/α-FeO photocatalyst. In this study we show that varying the mass ratio of α-FeO on BaTiO has a significant influence on photoinduced decolorization of rhodamine B under simulated sunlight. The highest photocatalytic activity was obtained for BaTiO-FeO-0.

Carbon-Nanodot Solar Cells from Renewable Precursors.

It has recently been shown that waste biomass can be converted into a wide range of functional materials, including those with desirable optical and electronic properties, offering the opportunity to find new uses for these renewable resources. Photovoltaics is one area in which finding the combination of abundant, low-cost and non-toxic materials with the necessary functionality can be challenging. In this paper the performance of carbon nanodots derived from a wide range of biomaterials obtained from different biomass sources as sensitisers for TiO -based nanostructured solar cells was compared; polysaccharides (chitosan and chitin), monosaccharide (d-glucose), amino acids (l-arginine and l-cysteine) and raw lobster shells were used to produce carbon nanodots through hydrothermal carbonisation.

Tuning the electrocaloric enhancement near the morphotropic phase boundary in lead-free ceramics.

The need for more energy-efficient and environmentally-friendly alternatives in the refrigeration industry to meet global emission targets has driven efforts towards materials with a potential for solid state cooling. Adiabatic depolarisation cooling, based on the electrocaloric effect (ECE), is a significant contender for efficient new solid state refrigeration techniques. Some of the highest ECE performances reported are found in compounds close to the morphotropic phase boundary (MPB).

Effect of Internal Electric Fields on Charge Carrier Dynamics in a Ferroelectric Material for Solar Energy Conversion.

Spontaneous polarization is shown to enhance the lifetimes of photogenerated species in BaTiO3 . This is attributed to polarization-induced surface band bending acting as a thermal barrier to electron/hole recombination. The study indicates that the efficiencies of solar cells and solar fuels devices can be enhanced by the use of ferroelectric materials.

Dye-Sensitized Solar Cells: The Future of Using Earth-Abundant Elements in Counter Electrodes for Dye-Sensitized Solar Cells (Adv. Mater. 20/2016).

Sustainability is an important concept generating traction in the research community. To be really sustainable the full life cycle of a product needs to be carefully considered. A key aspect of this is using elements that are either readily recycled or accessible in the Earth's biosphere.

The Future of Using Earth-Abundant Elements in Counter Electrodes for Dye-Sensitized Solar Cells.

With limited global resources for many of the elements that are found in some of the most common renewable energy technologies, there is a growing need to use "Earth-abundant" elements as a long-term solution to growing energy demands. The dye-sensitized solar cell has the potential to produce low-cost renewable energy, with inexpensive production and most components using Earth-abundant elements. However, the most commonly used material for the cell counter electrode (CE) is platinum, an extremely expensive and rare element.

Biomass-derived carbon quantum dot sensitizers for solid-state nanostructured solar cells.

New hybrid materials consisting of ZnO nanorods sensitized with three different biomass-derived carbon quantum dots (CQDs) were synthesized, characterized, and used for the first time to build solid-state nanostructured solar cells. The performance of the devices was dependent on the functional groups found on the CQDs. The highest efficiency was obtained using a layer-by-layer coating of two different types of CQDs.

Chemical protection of ZnO nanorods at ultralow pH To form a hierarchical BiFeO3/ZnO core-shell structure.

ZnO is an interesting material for photoactive and optoelectronic devices because of the wide range of available nanostructures and advantageous semiconducting properties. However, a significant drawback of ZnO is the low stability in high or low pH solutions. This has limited the development of ZnO core-shell materials for use in Z-scheme systems or photovoltaics, where any secondary phase is produced using chemical solution processing at low or high pH.

Enhanced performance with bismuth ferrite perovskite in ZnO nanorod solid state solar cells.

This paper reports for the first time the use of perovskite bismuth ferrite (BiFeO3 or BFO) on ZnO-based solid state solar cells using only chemical solution methods for materials synthesis. As ZnO has poor chemical stability in acidic and corrosive environments, a buffer method using aminosilane ((3-aminopropyltriethoxysilane or H2N(CH2)3Si(OC2H5)3)) coating was used to provide a protective coating on the ZnO nanorods. The aminosilane layer was removed after BFO coating.

Acoustic enhancement of polymer/ZnO nanorod photovoltaic device performance.

Acoustic vibrations are shown to enhance the photovoltaic efficiency of a P3HT/ZnO nanorod solar cell by up to 45%, correlated to a three-fold increase in charge carrier lifetime. This is assigned to the generation of piezoelectric dipoles in the ZnO nanorods, indicating that the efficiency of solar cells may be enhanced in the presence of ambient vibrations by the use of piezoelectric materials.

Recent progress in ZnO-based nanostructured ceramics in solar cell applications.

ZnO is widely used as an n-type semiconductor in various solar cell structures; including dye-sensitized, organic, hybrid and solid-state solar cells. Here, we review advances in ZnO-based solar cell applications, looking at the influence of morphology, as well as the effect of different materials and sensitizers. ZnO morphologies play an important role in changing the surface area and charge transport properties, affecting the performance of the solar cells.

Monoclonal TCR-redirected tumor cell killing.

T cell immunity can potentially eradicate malignant cells and lead to clinical remission in a minority of patients with cancer. In the majority of these individuals, however, there is a failure of the specific T cell receptor (TCR)–mediated immune recognition and activation process. Here we describe the engineering and characterization of new reagents termed immune-mobilizing monoclonal TCRs against cancer (ImmTACs).

LiNbO3--a new material for artificial photosynthesis.

The solid-gas phase photo-assisted reduction of carbon dioxide (artificial photosynthesis) was performed using ferroelectric lithium niobate and titanium dioxide. Illumination with a high-pressure mercury lamp and visible sunlight showed that lithium niobate achieved unexpectedly high conversion of CO(2) to products despite the low levels of band-gap light available. The high reaction efficiency of lithium niobate is explained by its strong remnant polarization (70 μC/cm(2)), allowing a longer lifetime of photo-induced carriers as well as an alternative reaction pathway.

Room temperature synthesis of crystalline alpha-Fe2O3 nanoparticles.

A room temperature process for the production of crystalline hematite Fe2O3 nanoparticles with an indirect band gap of 2 eV and size range from 15 to 35 nm is presented. The material to have an optical band gap of 2 eV as determined by the Tauc relationship which makes it suitable for visible light photocatalysis. The XRD pattern of the material shows no secondary phases to be present for the low temperature processed material.