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Significant breakthroughs have recently been made in boosting the hydrogen evolution reaction (HER) of Pt-containing electrocatalysts; however, it is unclear whether they can withstand long-term operational durability under the harsh industrial conditions, especially when driven by intermittent renewable energy. Here, a Pt-containing cathode was prepared by brushing a Pt–Ni solution onto Ni mesh (NM) (denoted as Pt–Ni/NM) and paired with a NM anode to study its stability under simulated industrial conditions (30 wt. % KOH, 60 °C). The assembled electrolyzer shows superior performance of water splitting, operating constantly under ∼500 mA/cm2 when the cell voltage is kept at 1.71 V. Unfortunately, the HER activity of the cathode degrades obviously when the cell voltage is under the "on/off" (1.71 V/0 V) states when simulating the supply of intermittent renewable energy. Comprehensive analyses revealed that the decline was attributed to the galvanic corrosion owing to the difference in redox potential between Ni and Pt. When the applied protective voltage on the "off" state exceeds such potential (∼0.58 V), the corrosion can be effectively alleviated, extending the stability to over 400 h. Furthermore, this protective strategy also shows effectiveness in improving the stability of other systems (e.g., Co–Ni), offering a promising way for practical applications in industrial alkaline water electrolysis. [ABSTRACT FROM AUTHOR]

Monolithic integrated photoelectrochemical devices consisting of semiconductors and co-catalysts have always been restricted by the trade-off between light absorption and catalytic activity upon frontside illumination. Herein, we proposed a facile strategy to spatio-selectively deposit Pt catalyst on the top of p-Si micro-pyramids, which not only enables substantial light absorption but also immensely boosts the charge transport and mass transfer. With the help of dark-field microscopy and microscopic photocurrent mapping, it is revealed that the top of p-Si micro-pyramids is an ideal electron-migration channel for efficient charge carrier extraction. This spatio-selective strategy affords the Si photocathode to achieve a high applied bias photon-to-current efficiency of 3.84% for hydrogen production, significantly greater than the control sample with the same amount of Pt catalyst deposited uniformly on the same substrates (0.04%). [ABSTRACT FROM AUTHOR]

Photoelectrochemical (PEC) water splitting has been intensively studied as a sustainable approach to directly convert intermittent solar energy into storable hydrogen fuels. Its practical application, however, has been tethered by the trade-off between photoelectrode efficiency and stability. Herein, this work demonstrates a facile strategy to design highly efficient and stable Si photocathodes by utilizing the reduced graphene oxide (rGO) as a multifunctional interlayer to bridge the Pt catalysts and p-Si. The covalently grafted rGO layer forms a Schottky junction with p-Si allowing effective charge carrier extraction required for high efficiency, and, simultaneously, protects the Si surface and anchors Pt catalysts with enhanced stability. Consequently, the as-fabricated Pt/rGO/p-Si photocathodes exhibit an impressive PEC performance under simulated AM1.5G illumination with a high applied bias photon-to-current efficiency (ABPE) of 4.9% and stability of over 110 hours, outperforming the Pt/p-Si control sample and state-of-the-art p-Si based photocathodes. In summary, this work offers a viable path for developing high-performance solar-to-fuel conversion devices in the future. [ABSTRACT FROM AUTHOR]

An approach for the analysis of atomically resolved scanning transmission electron microscopy data with multiple ferroic variants in the presence of imaging non-idealities and chemical variabilities based on a rotationally invariant variational autoencoder (rVAE) is presented. We show that an optimal local descriptor for the analysis is a sub-image centered at specific atomic units, since materials and microscope distortions preclude the use of an ideal lattice as a reference point. The applicability of unsupervised clustering and dimensionality reduction methods is explored and is shown to produce clusters dominated by chemical and microscope effects, with a large number of classes required to establish the presence of rotational variants. Comparatively, the rVAE allows extraction of the angle corresponding to the orientation of ferroic variants explicitly, enabling straightforward identification of the ferroic variants as regions with constant or smoothly changing latent variables and sharp orientational changes. This approach allows further exploration of the chemical variability by separating the rotational degrees of freedom via rVAE and searching for remaining variability in the system. The code used in this article is available at https://github.com/saimani5/ferroelectric_domains_rVAE. [ABSTRACT FROM AUTHOR]

Self-healing with the capability to be self-adhesive, which can recover from physical damage, is essential for space applications. However, regulatable adhesion under extreme space conditions has only been realized in low-dimensional materials and still poses a challenge on the discovery of suitable materials. Under an ultrahigh vacuum of 10−7 Pa, we found a strong adhesion between bulk Cu46Zr46Al8 metallic glasses with a maximum adhesion strength of 32.8 kPa, which is two orders of magnitude higher than that of the corresponding crystalline. This adhesion is suggested to be induced by a liquid-like layer on a bulk metallic glass surface, which has a high diffusion coefficient of 6.9 × 10−11 m2⋅s−1, even at a relatively low temperature of 263 K. By investigating the dynamics for this liquid-like layer, a special fractional Stokes–Einstein relationship was found. Inspired by this strong adhesion, metallic glasses can be proposed as one of the promising self-healing materials for future space applications. [ABSTRACT FROM AUTHOR]