以電化學沉積法結合酸蝕刻處理製備高效鎳電極於鹼性析氫反應

Abstract

中文摘要 為了滿足日益增加的氫氣需求，提升氫氣生產效率至關重要。本研究以兩步法優化鎳電極於鹼性析氫反應(Hydrogen evolution reaction, HER)中的表現。首先透過電化學沉積製備具五角錐結構的鎳電極，再經酸蝕刻處理調控表面結構與成分。結果顯示，酸蝕刻60 min後，其在10 mA/cm²下的HER過電位由238 mV降至60 mV，並於100 mA/cm²下穩定運作超過360小時，展現極佳的耐久性與長期穩定性。進一步分析表明，酸蝕刻處理有效提升電極表面粗糙度、電化學活性表面積(Electrochemical active surface area, ECSA) ，同時增強表面潤濕性並促進氫氣氣泡的快速脫附，降低了界面阻力，因而顯著提升催化效率。此外，此過程在電極表面形成 Ni/NiO 複合結構，能夠有效促進 HER 反應中的 Volmer 步驟，並透過金屬與氧化物之間的協同效應進一步強化催化活性。綜合上述結果，本研究不僅能顯著改善電極在鹼性 HER 中的性能，亦具備應用於大規模氫氣製備之潛力。

Abstract Meeting the rapidly increasing demand for hydrogen requires significant improvements in production efficiency. Herein, we present a two-step strategy to enhance the catalytic performance of nickel electrodes for the alkaline hydrogen evolution reaction (HER). Nickel electrodes with a pentagonal pyramid structure were first prepared via electrochemical deposition, followed by surface modification through acid etching. After 60 minutes of etching, the overpotential at 10 mA cm⁻² decreased from 238 mV to 60 mV, while the electrode exhibited stable operation at 100 mA cm⁻² for over 360 hours, demonstrating remarkable durability and long-term stability. Structural and electrochemical analyses reveal that acid etching increases surface roughness, enlarges the electrochemical active surface area (ECSA), improves wettability, and facilitates rapid hydrogen bubble detachment, thereby reducing interfacial resistance and boosting catalytic efficiency. In addition, the formation of a Ni/NiO composite structure promotes the Volmer step of HER and further enhances catalytic activity through a synergistic effect between the metal and oxide. Collectively, this work provides an effective approach to significantly improve nickel electrode performance in alkaline HER and highlights its potential for large-scale hydrogen production.