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Phase engineering is a critical strategy in electrocatalysis, as it allows for the modulation of electronic, geometric, and chemical properties to directly influence the catalytic performance. Despite its potential, phase engineering remains particularly challenging in thermodynamically stable perovskites, especially in a 2D structure constraint. Herein, we report phase engineering in 2D LaNiO3 perovskite using the strongly non‐equilibrium microwave shock method. This approach enables the synthesis of conventional hexagonal and unconventional trigonal and cubic phases in LaNiO3 by inducing selective phase transitions at designed temperatures, followed by rapid quenching to allow precise phase control while preserving the 2D porous structure. These phase transitions induce structural distortions in the [LaO]+ layers and the hybridization between Ni 3d and O 2p states, modifying local charge distribution and enhancing electron transport during the six‐electron urea oxidation process (UOR). The cubic LaNiO3 offers optimal electron transport and active site accessibility due to its high structural symmetry and open interlayer spacing, resulting in a low onset potential of 1.27 V and a Tafel slope of 33.1 mV dec−1 for UOR, outperforming most current catalysts. Our strategy features high designability in phase engineering, enabling various electrocatalysts to harness the power of unconventional phases. [ABSTRACT FROM AUTHOR]

The alkaline hydrogen evolution reaction (HER) is pivotal for sustainable energy production but is hindered by sluggish kinetics due to the necessity of water dissociation to supply protons, which presents a high energy barrier. To overcome this challenge, a novel approach is proposed involving the introduction and tuning of oxygen vacancies on the surface of CeO2 to construct and control frustrated Lewis pairs (FLPs) with dual active sites for enhanced water dissociation. First-principles calculations reveal that increasing the number of oxygen vacancies significantly improves the quantity and activity of FLP sites for efficient water dissociation. Guided by these calculations, 2D CeO2 nanosheets with varying concentrations of oxygen vacancies were synthesized, showing that those with the highest vacancy content exhibit exceptional HER performance, with an overpotential of 132 mV and a Tafel slope of 73 mV dec−1. These findings validate the theoretical model and underscore the potential of 2D CeO2 with FLP active sites as effective and stable HER catalysts. This study is anticipated to inform the development of advanced catalysts with FLP active sites for hydrogen evolution reactions in alkaline media. [ABSTRACT FROM AUTHOR]

Developing an efficient and stable oxygen evolution reaction (OER) catalyst is beneficial in various energy conversion and storage applications for achieving the "Carbon Neutrality" goal. Among the iron‐based perovskite oxides (AFeO3), LaFeO3 stands out as a preferred catalyst for electrocatalytic OER due to its exceptional selectivity in oxygen bonding at the A‐site. The introduction of A‐site substitution and controlled morphological engineering in perovskite structures has proven effective in enhancing the electrical conductivity and intrinsic catalytic activity. Nevertheless, the conventional A‐site substitution approach often involves prolonged high‐temperature calcination, leading to the agglomeration of nanostructures, particularly in two‐dimensional (2D) porous configurations. Herein, we introduce a novel method for synthesizing 2D porous LaFeO3 perovskite with A‐site Sr substitution using microwave shock. This microwave technique capitalizes on the benefits of transient heating and cooling, enabling simultaneous construction of 2D porous morphology and precise regulation of Sr substitution in one step. By conducting theoretical simulations of the electron configuration and analysis of crystal structure, we unveil the impact of Sr substitution on the OER activity of 2D porous LaFeO3. The synthesized La0.2Sr0.8FeO3 (LSFO‐8) catalyst exhibits an exceptional overpotential of 339 mV at 10 mA cm−2 and a small Tafel slope of 56.84 mV dec−1 in alkaline electrolyte. This investigation provides a fresh perspective for the design and engineering of electronic configuration in highly active 2D perovskite materials. [ABSTRACT FROM AUTHOR]

The development of earth-abundant-metal-based electrocatalysts with high efficiency and long-term stability for hydrogen evolution reaction (HER) is crucial for the clean and renewable energy application. Herein, we report a molten-salt method to synthesize Co-doped CaMn3O6 (CMO) nanowires (NWs) as effective electrocatalyst for HER. The as-obtained CaMn3−xCoxO6 (CMCO) exhibits a small onset overpotential of 70 mV, a required overpotential of 140 mV at a current density of 10 mA·cm−2, a Tafel slope of 39 mV·dec−1 in 0.1 M HClO4, and a satisfying long-term stability. Experimental characterizations combined with density functional theory (DFT) calculations demonstrate that the obtained HER performance can be attributed to the Co-doping which altered CMO' s surface electronic structures and properties. Considering the simplicity of synthesis route and the abundance of the pertinent elements, the synthesized CMCO shows a promising prospect as a candidate for the development of earth-abundant, metal-based, and cost-effective electrocatalyst with superior HER activity. Our results also establish a strategy of rational design and construction of novel electrocatalyst toward HER by tailoring band structures of transition metal oxides (TMOs). [ABSTRACT FROM AUTHOR]

The printed electronics technology can be used to efficiently construct smart devices and is dependent on functional inks containing well-dispersed active materials. Two-dimensional (2D) materials are promising functional ink candidates due to their superior properties. However, the majority 2D materials can disperse well only in organic solvents or in surfactant-assisted water solutions, which limits their applications. Herein, we report a lithium (Li)-ion exchange method to improve the dispersity of the Na2W4O13 nanosheets in pure water. The Li-ion-exchanged Na2W4O13 (LixNa2−xW4O13) nanosheets show highly stable dispersity in water with a zeta potential of −55 mV. Moreover, this aqueous ink can be sprayed on various substrates to obtain a uniform LixNa2−xW4O13 nanosheet film, exhibiting an excellent electrochromic performance. A complementary electrochromic device containing a LixNa2−xW4O13 nanosheet film as an electrochromic layer and Prussian white (PW) as an ion storage layer exhibits a large optical modulation of 75% at 700 nm, a fast switching response of less than 2 s, and outstanding cyclic stability. This Na2W4O13-based aqueous ink exhibits considerable potential for fabricating large-scale and flexible electrochromic devices, which would meet the practical application requirements. [ABSTRACT FROM AUTHOR]

Recently, rechargeable zinc‐ion batteries in mild acidic electrolytes have attracted considerable research interest as a result of their high sustainability, safety, and low cost. However, the use of conventional Zn‐ion storage materials is hindered by insufficient specific capacity, sluggish reaction kinetics, or poor cycle life. Here, these limitations are addressed by pre‐intercalating alkali ions and water crystals into layered δ‐MnO2 (birnessite) to prepare K0.27MnO2·0.54H2O (KMO) and Na0.55Mn2O4·1.5H2O with ultrathin nanosheet morphology via a rapid molten salt method. In these materials, alkali ions and water crystals act as pillars to stabilize the layered structures, which can enable rapid diffusion of cations in the KMO structure, resulting in high power capability (90 mAh g−1 at 10 C) and good cycling stability. Furthermore, electrochemical quartz crystal microbalance measurements shed light on the charge storage mechanism of KMO in an aqueous Zn‐ion battery which, combined together with in‐operando X‐ray diffraction techniques, suggests that the charge storage process is dominated by the (de)intercalation of H3O+ with further dissolution–precipitation of Zn4(OH)6(SO4)·5H2O solid product on the KMO surface during cycling. [ABSTRACT FROM AUTHOR]