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Despite intense interest in the catalytic potential of transition metal oxide heterostructures, originating from their large surface area and tunable chemistry, the fabrication of well-defined multicomponent oxide coatings with controlled architectures remains challenging. Here, we demonstrate a simple and effective swelling-assisted sequential infiltration synthesis (SIS) strategy to fabricate hierarchically porous multicomponent metal-oxide electrocatalysts with tunable bimetallic composition. A combination of solution-based infiltration (SBI) of transition metals, iron (Fe), nickel (Ni), and cobalt (Co), into a block copolymer (PS73-b-P4VP28) template, followed by vapor-phase infiltration of alumina using sequential infiltration synthesis (SIS), was employed to synthesize porous, robust, conformal and transparent multicomponent metal-oxide coatings like Fe/AlOx, Fe+Ni/AlOx, and Fe+Co/AlOx. Electrochemical assessments for the oxygen evolution reaction (OER) in a 0.1 M KOH electrolyte demonstrated that the Fe+Ni/AlOx composite exhibited markedly superior catalytic activity, achieving an impressive onset potential of 1.41 V and a peak current density of 3.29 mA/cm2. This superior activity reflects the well-known synergistic effect of alloying transition metals with a trace of Fe, which facilitates OER kinetics. Overall, our approach offers a versatile and scalable path towards the design of stable and efficient catalysts with tunable nanostructures, opening new possibilities for a wide range of electrochemical energy applications. 

Abstract Structural superlubricity (SSL) at layered material interfaces is an exciting and vibrant field of research, offering vast opportunities to achieve ultralow friction and wear with numerous potential technological applications. At increasing length‐scales, new physical and chemical energy dissipation pathways emerge that threaten to push the system out of the superlubric regime. Physical inhibitors of SSL are primarily associated with in‐plane elasticity, out‐of‐plane corrugation, moiré superlattices, grain boundaries, and lattice defects. Chemical mechanisms that may suppress superlubric behavior include interlayer bonding, wear, and external contaminants. In this article, these and other challenges are reviewed facing the scaling‐up of structural superlubricity, as reflected in recent experimental and theoretical studies. Further perspectives are offered on future directions for realizing and manipulating macroscale superlubricity, outlining technological opportunities that it entails. 

Electric vehicles (EVs) represent a new paradigm for a sustainable transportation future with the potential to offer unparalleled energy security, environmental cleanliness, and economic prosperity for all humanity. However, rapid development and adaptation of this new transportation approach depend on addressing multiple challenges, including the development of new materials and coatings that can meet the more stringent thermal, electrical, and tribological requirements of EV drivetrains. Specifically, the operating conditions of moving mechanical assemblies (i.e., bearings, gears, among others) in EVs differ radically from those found in conventional internal combustion (IC) engines—thus giving rise to notable reliability issues. In particular, as the function of bearings and gear systems shift from mostly load-carrying (in IC engines) to the torque-transferring mode in EVs, durability concerns of these assemblies due to severe deformation, wear, micro-pitting, fatigue, and scuffing may worsen—as electric motors can generate maximum torque at near zero speeds but maximum efficiency at around 90% speed (this is opposite of conventional IC engines, which generate high torques at high speeds). These conflicting requirements require a different set of lubricant-material combinations to circumvent such problems under high loads and low-speed conditions of EVs. Therefore, new materials, coatings, and lubrication strategies need to be developed and implemented for future EVs to become tribologically viable and reliable. Accordingly, EV drivetrains can potentially benefit from advanced functional coatings that have already significantly improved the functionality of moving components of IC engines. The main objective of this article is to draw attention to some of the tribological issues in EVs and how advanced functional coatings can help resolve these issues due to their unique thermal, electrical, mechanical, and tribological properties, ultimately making EVs more durable and reliable.