Water splitting is an overgrowing research field and there is a huge challenge to develop easily accessible and applied methods for facile fabrication of durable electroactive thin-film catalysts. Here we demonstrate a simple cost-effective spray-coating strategy to develop ultrathin and highly crystalline CoO_x nanoparticulate thin-films as a bifunctional electrocatalyst for overall water splitting. During electrocatalysis, nanoscale surface-coated CoO_x (SC-CoO_x NPs) exhibits high activity while initiating OER and HER just at 1.48 V_RHE and 0.22 V_RHE, respectively, and displayed current decades for OER and HER at an overpotential of 300 mV and 350 mV, respectively. Furthermore, the high electrochemically active surface area of 301 cm², facile electrode kinetics and low charge transfer resistance at electrode-electrolyte interphase are observed that promote efficient electron transfer and facilitate adsorption/desorption of various intermediates during water splitting process thus making it energy efficient. DFT calclations also suggest that the electrode is very feasible for water oxidation catalysis which is ruling reaction under employed conditions. The electrocatalyst also presented superior long-term durabilities during extended period water electrolysis experiments. The present material, method and approach of growing metal-oxide nanoscale and thin-film assemblage of catalytic materials can offer an exciting and straightforward approach for producing highly applied catalytic materials.

水分解是一个飞速发展的研究领域，并且开发易于制造和应用的方法来快速制造耐用的电活性薄膜催化剂存在着巨大的挑战。在这里，我们展示了一种简单的具有成本效益的喷涂策略，可开发出超薄且高度结晶的CoO _x纳米颗粒薄膜，作为用于整体水分解的双功能电催化剂。在电催化过程中，纳米级表面涂层CoO _x（SC-CoO _x NPs）表现出高活性，同时仅在1.48 V _RHE和0.22 V _RHE处引发OER和HER，并分别以300 mV和350 mV的过电势显示OER和HER的当前数十年。此外，具有301 cm ²的高电化学活性表面积观察到在电极-电解质界面处的容易的电极动力学和低的电荷转移阻力，这在水分解过程中促进了有效的电子转移并促进了各种中间体的吸附/解吸，从而使其具有能源效率。DFT的计算也表明该电极对于水氧化催化是非常可行的，这是在所采用的条件下的主要反应。在长时间的水电解实验中，该电催化剂还具有优异的长期耐久性。生长催化材料的金属氧化物纳米级和薄膜组件的本材料，方法和方法可为生产高度应用的催化材料提供令人兴奋且直接的方法。