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challenge and can provide an adequate pathway to store renewable energy in the form of hydrogen fuel. [2] Oxygen evolution reaction (OER) is however a half-reaction that largely limits the efficiency of water splitting, as emphasized in fundamental catalysis recently, [3] where the multiple electron-proton coupled transfer steps of the OER process often lead to sluggish kinetics and high overpotentials, and therefore limit the device performance at increased operating costs. [4,5] There is therefore an urgent need for high-performance electrocatalysts to reduce the energy barrier and accelerate the catalytic reaction to improve the overall energy conversion efficiency. In general, the currently known state-of-the-art electrolysis technology requires the use of Ru/Ir-based electrocatalysts as the OER electrodes. [6] However, the high cost of these precious metals apparently impedes their largescale applications. [7,8] On the other hand, although transition metal compounds (TMC) with earth abundance, multifunctional redox valence, and unsaturated transition metal sites have been widely studied, their inherently poor activity and unsatisfactory long term stability need to be further improved. [9][10][11] The development of highly active and durable electrocatalysts is therefore of great significance for accelerating the application of OER.The electrochemical oxygen evolution reaction (OER) by efficient catalysts is a crucial step for the conversion of renewable energy into hydrogen fuel, in which surface/near-surface engineering has been recognized as an effective strategy for enhancing the intrinsic activities of the OER electrocatalysts. Herein, a facile quenching approach is demonstrated that can simultaneously enable the required surface metal doping and vacancy generation in reconfiguring the desired surface of the NiCo 2 O 4 catalyst, giving rise to greatly enhanced OER activities in both alkaline freshwater and seawater electrolytes. As a result, the quenched-engineered NiCo 2 O 4 nanowire electrode achieves a current density of 10 mA cm −2 at a low overpotential of 258 mV in 1 m KOH electrolyte, showing the remarkable catalytic performance towards OER. More impressively, the same electrode also displays extraordinary activity in an alkaline seawater environment and only needs 293 mV to reach 10 mA cm −2 . Density functional theory (DFT) calculations reveal the strong electronic synergies among the metal cations in the quench-derived catalyst, where the metal doping regulates the electronic structure, thereby yielding near-optimal adsorption energies for OER intermediates and giving rise to superior activity. This study provides a new quenching method to obtain high-performance transition metal oxide catalysts for freshwater/seawater electrocatalysis.

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Solar interface water evaporation has been demonstrated to be an advanced method for freshwater production with high solar energy utilization. The development of evaporators with lower cost and higher efficiency is a key challenge in the manufacture of practical solar interface water evaporation devices. Herein, a bamboo leaf‐derived carbon‐based evaporator is designed based on the light trace simulation. And then, it is manufactured by vertical arrangement and carbonization of bamboo leaves and subsequent polyacrylamide modification. The vertically arranged carbon structure can extend the light path and increase the light‐absorbing area, thus achieving excellent light absorption. Furthermore, the continuous distribution of polyacrylamide hydrogel between these vertical carbons can support high‐speed water delivery and shorten the evaporation path. Therefore, this evaporator exhibits an ultrahigh average light absorption rate of ˜96.1%, a good water evaporation rate of 1.75 kg m–2 h−1, and an excellent solar‐to‐vapor efficiency of 91.9% under one sun irradiation. Furthermore, the device based on this evaporator can effectively achieve seawater desalination, heavy metal ion removal, and dye separation while completing water evaporation. And this device is highly available for actual outdoor applications and repeated recycling.