Pulsed-Current Operation Enhances HO Production on a Boron-Doped Diamond Mesh Anode in a Zero-Gap PEM Electrolyzer.

A niobium (Nb) mesh electrode was coated with boron-doped diamond (BDD) using chemical vapor deposition in a custom-built hot-filament reactor. The BDD-functionalized mesh was tested in a zero-gap electrolysis configuration and evaluated for the anodic formation of HO by selective oxidation of water, including the analysis of the effects on Faradaic efficiency towards HO (FEH2O2) induced by pulsed electrolysis. A low electrolyte flow rate (V⋅) was found to result in a relatively high concentration of HO in single-pass electrolysis experiments.

Functionalized Substrates for Reduced Nonradiative Recombination in Metal-Halide Perovskites.

Reducing nonradiative recombination is crucial for minimizing voltage losses in metal-halide perovskite solar cells and achieving high power conversion efficiencies. Photoluminescence spectroscopy on complete or partial perovskite solar cell stacks is often used to quantify and disentangle bulk and interface contributions to nonradiative losses. Accurately determining the intrinsic loss in a perovskite layer is key to analyzing the origins of nonradiative recombination and developing defect engineering strategies.

Performance and stability analysis of all-perovskite tandem photovoltaics in light-driven electrochemical water splitting.

All-perovskite tandem photovoltaics are a potentially cost-effective technology to power chemical fuel production, such as green hydrogen. However, their application is limited by deficits in open-circuit voltage and, more challengingly, poor operational stability of the photovoltaic cell. Here we report a laboratory-scale solar-assisted water-splitting system using an electrochemical flow cell and an all-perovskite tandem solar cell.

Steering perovskite precursor solutions for multijunction photovoltaics.

Multijunction photovoltaics (PVs) are gaining prominence owing to their superior capability of achieving power conversion efficiencies (PCEs) beyond the radiative limit of single-junction cells, where improving narrow bandgap tin-lead perovskites is critical for thin-film devices. With a focus on understanding the chemistry of tin-lead perovskite precursor solutions, we herein find that Sn(II) species dominate interactions with precursors and additives and uncover the exclusive role of carboxylic acid in regulating solution colloidal properties and film crystallisation, and ammonium in improving film optoelectronic properties. Materials that combine these two function groups, amino acid salts, considerably improve the semiconducting quality and homogeneity of perovskite films, surpassing the effect of the individual functional groups when introduced as part of separate molecules.

Separating triplet exciton diffusion from triplet-triplet annihilation by the introduction of a mediator.

Triplet-triplet annihilation photon upconversion (TTA-UC) combines the energy of two photons to provide one of higher energy that can be used to drive photochemical or photophysical processes. TTA-UC proceeds at high efficiencies in dilute solution, but in solid state the efficiency drastically reduces. This is because exciton diffusion, compared to molecular diffusion in solid annihilator films, suffers concentration induced quenching, undermining efficient emission.

Specific heat analyses on optical-phonon-derived uniaxial negative thermal expansion system TrZr (tr = fe and CoNi).

A large uniaxial negative thermal expansion (NTE) along the c-axis has recently been observed in the transition metal (Tr) zirconides TrZr with a tetragonal CuAl-type structure. A recent study on FeZr₂ [M. Xu et al.

Enhanced Catalytic Probe Design for Mapping Radical Density in the Plasma Afterglow.

The electrification of chemical processes using plasma generates an increasing demand for sensors, monitoring concentrations of plasma-activated species such as radicals. Radical probes are a low-cost in situ method for spatially resolved quantification of the radical density in a plasma afterglow using the heat from the exothermal recombination of radicals on a catalytic surface. However, distinguishing recombination heating from other heat fluxes in the system is challenging.

Solar Light CO Photoreduction Enhancement by Mononuclear Rhenium(I) Complexes: Characterization and Mechanistic Insights.

The catalytic efficacy of a novel mononuclear rhenium(I) complex in CO reduction is remarkable, with a turnover number (TON) of 1517 in 3 h, significantly outperforming previous Re(I) catalysts. This complex, synthesized via a substitution reaction on an aromatic ring to form a bromo-bipyridine derivative, = 2-bromo-6-(1-pyrazol-1-yl)pyridine, and further reacting with [Re(CO)Cl], results in the facial-tricarbonyl complex [ReL1(CO)Cl] (). The light green solid was obtained with an 80% yield and thoroughly characterized using cyclic voltammetry, nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR) spectroscopy, and ultraviolet-visible (UV-vis) spectroscopy.

Quantifying concentration distributions in redox flow batteries with neutron radiography.

The continued advancement of electrochemical technologies requires an increasingly detailed understanding of the microscopic processes that control their performance, inspiring the development of new multi-modal diagnostic techniques. Here, we introduce a neutron imaging approach to enable the quantification of spatial and temporal variations in species concentrations within an operating redox flow cell. Specifically, we leverage the high attenuation of redox-active organic materials (high hydrogen content) and supporting electrolytes (boron-containing) in solution and perform subtractive neutron imaging of active species and supporting electrolyte.

Controlling a new plasma regime.

Success of the UK's Spherical Tokamak for Energy Production (STEP) programme requires a robust plasma control system. This system has to guide the plasma from initiation to the burning phase, maintain it there, produce the desired fusion power for the desired duration and then terminate the plasma safely. This has to be done in a challenging environment with limited sensors and without overloading plasma-facing components.

Polaritonic Chemistry Enabled by Non-Local Metasurfaces.

Vibrational strong coupling can modify chemical reaction pathways in unconventional ways. Thus far, Fabry-Perot cavities formed by pairs of facing mirrors have been mostly utilized to achieve vibrational strong coupling. In this study, we demonstrate the application of non-local metasurfaces that can sustain surface lattice resonances, enabling chemical reactions under vibrational strong coupling.

Unraveling NO Production in N-O Plasmas with 0D Kinetic Modeling and Experimental Validation.

This work presents a detailed investigation aimed at understanding the key mechanisms governing nitric oxide (NO) production in N-O discharges by systematically comparing experimental results to modeling data. The experimental phase capitalizes on radiofrequency (13.56 MHz) discharges, sustained at 5 mbar pressure conditions, featuring varying concentrations of oxygen, ranging from pure N plasma to air-like mixtures.

Exploring novel circulating biomarkers for liver cancer through extracellular vesicle characterization with infrared spectroscopy and plasmonics.

Background: Hepatocellular carcinoma (HCC) is the most common form of liver cancer, with cirrhosis being a major risk factor. Traditional blood markers like alpha-fetoprotein (AFP) demonstrate limited efficacy in distinguishing between HCC and cirrhosis, underscoring the need for more effective diagnostic methodologies. In this context, extracellular vesicles (EVs) have emerged as promising candidates; however, their practical diagnostic application is restricted by the current lack of label-free methods to accurately profile their molecular content.

Sub-bandgap Photocurrent Spectra of p-i-n Perovskite Solar Cells with n-Doped Fullerene Electron Transport Layers and Bias Illumination.

In p-i-n perovskite solar cells optical excitation of defect states at the interface between the perovskite and fullerene electron transport layer (ETL) creates a photocurrent responsible for a distinct sub-bandgap external quantum efficiency (EQE). The precise nature of these signals and their impact on cell performance are largely unknown. Here, the effect of n-doping the fullerene on the EQE spectra is studied.

Unraveling the Role of the Stoichiometry of Atomic Layer Deposited Nickel Cobalt Oxides on the Oxygen Evolution Reaction.

Nickel cobalt oxides (NCOs) are promising, non-precious oxygen evolution reaction (OER) electrocatalysts. However, the stoichiometry-dependent electrochemical behavior makes it crucial to understand the structure-OER relationship. In this work, NCO thin film model systems are prepared using atomic layer deposition.

Atomically Engineered Encapsulation of SnS Nanoribbons by Single-Walled Carbon Nanotubes for High-Efficiency Lithium Storage.

Rechargeable lithium-ion batteries are integral to contemporary energy storage, yet current anode material systems struggle to meet the increasing demand for extended range capabilities. This work introduces a novel composite anode material composed of one-dimensional 2H-phase tin disulfide (SnS) nanoribbons enclosed within cavities of single-walled carbon nanotubes (SnS@SWCNTs), achieved through precise atomic engineering. Employing aberration-corrected transmission electron microscopy, we precisely elucidated the crystal structure of SnS within the confines of the SWCNTs.

ML-Aided Computational Screening of 2D Materials for Photocatalytic Water Splitting.

The exploration of two-dimensional (2D) materials with exceptional physical and chemical properties is essential for the advancement of solar water splitting technologies. However, the discovery of 2D materials is currently heavily reliant on fragmented studies with limited opportunities for fine-tuning the chemical composition and electronic features of compounds. Starting from the V2DB digital library as a resource of 2D materials, we set up and execute a funnel approach that incorporates multiple screening steps to uncover potential candidates for photocatalytic water splitting.

Effect of sub-bandgap defects on radiative and non-radiative open-circuit voltage losses in perovskite solar cells.

The efficiency of perovskite solar cells is affected by open-circuit voltage losses due to radiative and non-radiative charge recombination. When estimated using sensitive photocurrent measurements that cover the above- and sub-bandgap regions, the radiative open-circuit voltage is often unphysically low. Here we report sensitive photocurrent and electroluminescence spectroscopy to probe radiative recombination at sub-bandgap defects in wide-bandgap mixed-halide lead perovskite solar cells.

Climbing the Hydrogen Evolution Volcano with a NiTi Shape Memory Alloy.

Alkaline water electrolysis is a sustainable way to produce green hydrogen using renewable electricity. Even though the rates of the cathodic hydrogen evolution reaction (HER) are 2-3 orders of magnitude less under alkaline conditions than under acidic conditions, the possibility of using non-precious metal catalysts makes alkaline HER appealing. We identify a novel and facile route for substantially improving HER performance via the use of commercially available NiTi shape memory alloys, which upon heating undergo a phase transformation from the monoclinic martensite to the cubic austenite structure.

Impact of Alkyl Chain Length on the Formation of Regular- and Reverse-Graded Quasi-2D Perovskite Thin Films.

Crystallization of low-dimensional perovskites is a complex process that leads to multidimensional films comprising two-dimensional (2D), quasi-2D, and three-dimensional (3D) phases. Most quasi-2D perovskite films possess a regular gradient with 2D phases located at the bottom of the film and 3D phases at the top. Recently, multiple studies have reported reverse-graded perovskite films, where the location of the 2D and 3D structures is inverted.

Towards the 4 V-class n-type organic lithium-ion positive electrode materials: the case of conjugated triflimides and cyanamides.

Organic electrode materials have garnered a great deal of interest owing to their sustainability, cost-efficiency, and design flexibility metrics. Despite numerous endeavors to fine-tune their redox potential, the pool of organic positive electrode materials with a redox potential above 3 V Li/Li, and maintaining air stability in the Li-reservoir configuration remains limited. This study expands the chemical landscape of organic Li-ion positive electrode chemistries towards the 4 V-class through molecular design based on electron density depletion within the redox center the mesomeric effect of electron-withdrawing groups (EWGs).

Electrochemical Activation of Atomic-Layer-Deposited Nickel Oxide for Water Oxidation.

NiO-based electrocatalysts, known for their high activity, stability, and low cost in alkaline media, are recognized as promising candidates for the oxygen evolution reaction (OER). In parallel, atomic layer deposition (ALD) is actively researched for its ability to provide precise control over the synthesis of ultrathin electrocatalytic films, including film thickness, conformality, and chemical composition. This study examines how NiO bulk and surface properties affect the electrocatalytic performance for the OER while focusing on the prolonged electrochemical activation process.