Hydrogen production by electrochemical overall water splitting is an economic and green approach to resolve the looming energy and environmental crisis. However, the electrocatalytic oxygen evolution reaction (OER) generally occurs at low rate due to the delayed reaction kinetics of four-electron transfer. Herein, a kind of crater-like micro-nano structure CuS three-dimensional electrode that was supported on a Cu foam was prepared and used as an electrode anode for overall water splitting. The superhydrophilic/underwater superaerophobic structure can significantly reduce the bubble adhesion on the electrode surface and improve the OER performance. The CuS/CF electrode showed good wettability and superaerophobicity with an underwater contact angle of 153.5°. The CuS/CF (CuS/Cu foam) electrode has been proved to have excellent electrocatalytic activity for water decomposition. In 1.0 M KOH solution, the OER overpotential is 350 mV at 10 mA cm −2 and the Tafel slope is 83 mV dec −1 . In acidic medium of 0.5 M H 2 SO 4 solution, the overpotential of hydrogen evolution (HER) is 134 mV at 10 mA cm −2 and the Tafel slope is 114 mV dec −1 . The underwater superaerophobic electrode still has strong stability after 10 h test. This work provides a new potential electrochemical catalyzed approach to water decomposition by constructing a super-infiltration electrode.
Liu Yang,Yang Jingdong,Wen Jiaxin,Ye Junliu,Liu Huan,Lu Liwei
Recently, rechargeable magnesium-ion batteries (MIBs) and rechargeable magnesium/lithium hybrid-ion batteries (MLHBs) have gained recognition as promising energy storage devices. However, the conventional CuS cathodes exhibit sluggish kinetics and poor cycle stability, thereby impeding the advancement and application of CuS. In this work, we have developed an economical and simple in-situ approach for synthesizing CuS@Cu foam (CSC) and evaluated its potential as a cathode material for both MIBs and MLHIBs. In both MIBs and MLHIBs, the CSC cathode demonstrates competitive performance. In MIBs, at a current density of 100 mA g −1 , the initial discharge specific capacity of the CSC is 150.94 mAh g −1 , which is higher than that of commercial CuS (3.99 mAh g −1 ). In MLHIBs, the CSC exhibits a discharge specific capacity of 502.95 mAh g −1 after 70 cycles at a current density of 100 mA g −1 , which significantly surpasses the discharge specific capacity of commercial CuS (229.52 mAh g −1 ). This performance improvement is attributed to the presence of Li + ions, which expedite the reaction kinetics, obviate the need for an activation process, and effectively facilitate the conversion reaction. In conclusion, by in-situ synthesis of CSC, the active material CuS firmly adheres to the Cu foam current collector. This approach is not only economical and simple but also significantly enhances the reactivity of the electrode material, thereby improving the electrochemical performance. This work provides valuable insights for the design, synthesis, and performance optimization of cathode materials of magnesium metal-based batteries.
危险品化学品经营许可证（带存储）