Facile synthesis of highly efficient and low‐cost electrocatalyst for oxygen evolution reaction (OER) is important for large‐scale hydrogen production. Herein, nickel hydroxide/reduced graphene oxide (Ni(OH)₂/rGO) composite thin film was fabricated using dip‐coating followed by electrodeposition method on Ni foam substrate at room temperature. The deposited composite film shows amorphous nature with ultra‐thin Ni(OH)₂ nanosheets vertically coated on rGO surface, which provides large electrochemical surface area and abundant catalytically active sites. It exhibits a low overpotential of 260 mV @10 mA cm⁻² as compared to the pristine electrodes and excellent long‐term stability up to 20 hours in 1 M KOH solution. The electrochemical active surface area and Tafel slope of the composite electrode are 20.2 mF cm⁻² and 35 mV dec⁻¹, respectively. The superior water oxidation performance is a result of high catalytically active sites and improved conductivity of the composite electrode.

中文翻译：

---

氢氧化镍/还原氧化石墨烯复合薄膜的制备及其在水分解中的应用

高效，低成本的用于氧气析出反应（OER）的电催化剂的合成对于大规模制氢至关重要。在此，在室温下在镍泡沫基底上采用浸涂和电沉积法制备了氢氧化镍/还原氧化石墨烯（Ni（OH）₂ / rGO）复合薄膜。沉积的复合膜表现出非晶态性质，在rGO表面上垂直涂覆了超薄的Ni（OH）₂纳米片，提供了较大的电化学表面积和丰富的催化活性位。它在10 mA cm ^-2时表现出260 mV的低过电势与原始电极相比，在1 M KOH溶液中长达20小时具有出色的长期稳定性。复合电极的电化学活性表面积和Tafel斜率分别为20.2mF cm ^-2和35mV dec ^-1。优异的水氧化性能是高催化活性位点和复合电极电导率提高的结果。