Abstract The development of platinum group metal (PGM)‐free catalysts is essential to advance the wide application of fuel cells. Single‐atom Fe─N─C catalysts are one type of promising PGM‐free catalysts that can replace the expensive Pt/C catalyst for the electrocatalytic oxygen reduction reaction. However, Fe─N─C catalysts still suffer from poor stability due to the inevitable Fenton reaction. In this work, a doping strategy is demonstrated to alter the electronic structure around the catalytic sites and significantly improve their catalytic activity. In particular, the phosphorous‐doped Fe─N─C catalyst (P─Fe─N─C) achieves a half‐wave potential of 0.885 V versus RHE in 0.1 m KOH and demonstrates excellent stability, with only a 7 mV decay in the half‐wave potential after 10 000 cyclic voltammetry cycles, superior to that of boron‐doped one (B─Fe─N─C). Density functional theory (DFT) calculations further confirm that heteroatom doping favors the ORR process, highlighting the potential of this catalyst for advanced energy applications.

Abstract A detailed understanding of nanoscale heat transport at metal oxide‐hydrocarbon interfaces is critical for many applications that require efficient thermal management. Under ambient conditions, water nanofilms are expected to form at these interfaces, but these are rarely accounted for in simulations. Using molecular dynamics simulations, it is shown that water nanofilms at the hydroxylated hematite/poly‐α‐olefin (PAO) interface significantly affect wettability and thermal transport. Including water nanofilms improves agreement with experimental work of adhesion, which cannot be replicated with anhydrous systems using realistic solid–liquid interactions. For water films thicker than one monolayer, interfacial thermal resistance (ITR) converges to a consistent value, independent of solid–liquid interaction strength. This value is dominated by the ITR at the water/PAO interface. The ITR at the water/PAO interface is dependent on the surface area between the water film and the PAO and the magnitude of the interfacial potential. These simulations provide a more precise estimate of ITR at the hematite/PAO interface by accounting for surface hydration expected in experiments under ambient conditions. This study offers crucial insights into the roles of surface hydroxylation and water nanofilms in controlling wettability and thermal transport at industrially important interfaces.

Abstract Laser color marking produces nearly permanent, environmentally friendly, vibrant colors on surfaces. However, previous work has used high‐power‐density pulsed lasers to induce the physicochemical reactions for marking. Here, laser color marking on stainless steel 304 (SS304) is performed with a less expensive continuous wave (CW) laser and a power density five orders of magnitude below that previously reported by combining an electrochemical cell with a fluorescence microscope. Using a combination of optical microscopy, x‐ray photoelectron spectroscopy, and bulk electrochemistry, it is demonstrated that the laser‐induced luminescence and colors are due to enrichment (32 ± 9% increase) of Cr2O3 in the SS304 passive film. It is shown that the enrichment proceeds by a different chemical mechanism than the oxygen pyrolysis that occurs in typical laser color marking. The technique provides a new pathway for laser color marking of metals in industrial settings with applications as diverse as solar absorbers or corrosion prevention.

Abstract The fascinating optoelectronic properties of Metal Halide Perovskites (MHPs) have renewed interest in the development of innovative photovoltaic devices. Controlling the MHP crystallization process is crucial for achieving high‐performing solar cells especially when scaling up deposition technologies. To this aim, this work leverages a practical toolkit of characterization techniques to model the crystallization kinetics of MHPs and additives. The crystallization kinetics of MHPs from solution mediated by the starch is taken as a reference, with a glance at scalable printing techniques. The study of the equilibrium of chemical species in solution shows that starch influences the balance of ionic species, stabilizing the lead(II)iodide‐methylammonium iodide‐dimethylsulfoxide(PbI2·MAI·DMSO) adduct and causing dissociation of MAI aggregates. A combination of Differential scanning calorimetry (DSC) and Thermogravimetric analysis (TGA) analyses, using the Kissinger model, reveals a heterogeneous crystallization mechanism with delayed crystallization mediated by the starch, leading to the formation of the characteristic Liesegang ring grains. Upscaling deposition via blade coating further demonstrates that starch mitigates intrinsic stress during deposition in open air, resulting in a smoother, more homogeneous perovskite film with minimal gaps. This approach highlights the crucial role of starch in MHPs crystallization, providing insights into the dynamics that influence MHP properties and performance, while enabling further scalable deposition techniques.

Abstract The stability and performance of metal halide perovskite (MHP) optoelectronic devices are significantly influenced by the chemical and electronic properties of their interfaces, often studied using photoelectron spectroscopy (PES). MHP films, containing organic cations, are susceptible to surface modifications under common experimental conditions, necessitating careful analysis. This study examines the effects of argon gas cluster ion beam (GCIB) sputtering, considered gentler and more suitable for depth‐profiling than standard argon ion sputtering, on methylammonium lead iodide using PES. Long‐term exposure to argon clusters with 3.2 and 1.5 eV per Ar atom causes significant degradation, including cation loss and metallic lead formation. However, short‐term exposure (<60 min) at 1.5 eV per Ar atom effectively reduces surface contamination without noticeable degradation, allowing access to intrinsic electronic properties. This gentle cleaning reveals a 220 meV energy difference between the contaminated surface and the valence band onset of the intrinsic MHP potentially improving energy level alignment with electron transport layers. These results demonstrate that low energy GCIB sputtering can serve as a non‐destructive surface cleaning method, enhancing PES investigations and supporting fundamental device studies of MHPs.

Abstract While the growing utilization of polymers in flexible electronic devices has sparked significant interest in polymer/metal interfaces, spintronic studies of such interfaces remain limited. Here, spin pumping across a polymer/ferromagnet metal interface is systematically studied between hydrogen silsesquioxane (HSQ) oligomer layers (tHSQ = 30, 36, 48 nm) and NiFe (tNiFe = 4, 5, 7, 10 nm) thin films. Using ferromagnetic resonance measurements, strong spin pumping (large linewidth broadening) and a giant spin mixing conductance, reaching 19.8 nm−2 for HSQ = 48 nm are observed, i.e. comparable to that of heavy metals. The results suggest efficient spin transfer across the HSQ/NiFe interface, possibly originating from a combination of spin and orbital pumping, and provide valuable insights for designing self‐powered and flexible spintronic devices utilizing polymers in combination with ferromagnetic materials.

Abstract Solid‐state hydrogen storage materials with optimal binding energy are essential for hydrogen storage and transportation applications and pose long‐standing challenges. Current technologies, including molecular physisorption materials (e.g., metal–organic frameworks (MOFs), carbon nanotubes (CNTs), activated carbons (ACs)) and atomic chemisorption materials (e.g., MgH2, LiBH4, NH4BH4), fall short of meeting practical application requirements. Therefore, designing and constructing new solid‐state hydrogen storage materials at the atomic level is critically important. In this study, the use of defect engineering is explored to modulate hydrogen adsorption sites on TiO2 surfaces. The results demonstrate that low‐coordinated titanium (Ti) atoms on TiO2 can serve as effective hydrogen adsorption sites, storing hydrogen through molecular chemisorption with significantly enhanced adsorption energy compared to Ti atoms in high coordination states. Moreover, the adsorbed hydrogen remains in molecular form, facilitating easy desorption at room temperature, unlike titanium hydride, which requires high temperatures for desorption. This approach provides a promising pathway for developing efficient hydrogen storage materials by leveraging the unique properties of low‐coordinated Ti atoms on TiO2 surfaces.

The authors regret to inform the readers that incorrect images for Cu@G NMs-50.0%,tracking the catalytic reduction of MB in Figure 8a, were mistakenly included in the original publication.The error occurred during the image compilation process, where individual images were assembled into a single figure using PowerPoint.During this process, images from Cu@G NMs-20.0%and Cu@G NMs-10.0%were inadvertently reused in place of those for Cu@G NMs-50.0%.The corrected Figure 8a, showing the catalytic reduction of MB in Cu@G NMs-50.0%, is provided below.The authors confirm that this error does not affect any of the experimental results or the conclusions presented in the paper.The authors sincerely apologize for this error. Corrected Figure 8aFigure 8. Successive digital images to track the catalytic reduction of MB a) with NaBH 4 in the presence of Cu@G NMs synthesized with 10.0-100.0% of NH 3 .

Abstract TiNb2O7 (TNO) is a promising Li‐ion battery anode for high‐power applications, such as implantable medical devices and heavy‐duty equipment. Hailed as being safe due to its elevated operating potential near 1.6 V, TNO has long been assumed to be highly stable in the carbonate‐based electrolytes used in Li‐ion batteries. Herein, all mechanisms occurring at the surface of both TNO and Nd‐doped TNO are identified, and both materials in fact show significant gassing. CO2 is even released at open circuit conditions, demonstrating the poor chemical stability of the material in the electrolyte even prior to battery operation. Such extreme instability is a critical safety concern. In addition, it was found that Ti dissolves from the surface of TNO particles at low voltage (below 1.4 V vs Li), and in fact deposits on the counter electrode. Ti further inside TNO particles then diffuses to the Ti‐poor surface during discharge. Partial carbon‐coating as a mitigating measure has also been tested and found to exacerbate these processes. The findings identify novel reactions occurring within TNO, and clearly highlight the need to stabilize the surfaces of TNO in order to prevent such aggressive deterioration at the surface of the particles.

Magnetic-Field-Assisted Crystallization Magnetic-field-assisted crystallization of MAPbI3 single crystals induces compressive lattice strain, enhancing hole mobility, carrier lifetime, and thermal stability. This novel synthesis approach aligns the magnetic dipole moments of the MA+ ions using a magnetic field, optimizing optoelectronic properties for advanced device applications. More details can be found in article 2400781 by Yoonmi Choi, Jonghoo Park, and co-workers.