Low-cost and efficient electrocatalysts for oxygen evolution reaction (OER) are the key to electrolytic water splitting of water to produce high purity hydrogen as a green energy source. Construction of nanoarrays on conductive substrates is an effective way to obtain high OER performance, due to the high surface area, enhanced mass diffusion and low interface resistance between catalysts and collectors. To achieve these merits, effective control in the composition, phase structure and size of nanoarrays is highly desirable. Herein, nanosheet arrays of single-phase Co₃O₄, NiO and Co₃O₄/NiO nanocomposites were directly grown on carbon cloth by an electrodeposition method. The composition can be finely tuned via changing the Ni²⁺/Co²⁺ ratio in the electrodeposition solution. The thickness and plane size of the nanosheets can be also well controlled. The effects of size, composition and phase on the OER activity were investigated in detail. The optimized nanosheet arrays were further coated with a NiO layer to achieve an even enhanced OER activity.

用于氧气析出反应（OER）的低成本高效电催化剂是电解将水分解成高纯度氢作为绿色能源的水的关键。由于高表面积，增强的质量扩散和催化剂与集电体之间的低界面电阻，在导电基材上构建纳米阵列是获得高OER性能的有效方法。为了实现这些优点，非常需要对纳米阵列的组成，相结构和大小进行有效控制。在此，通过电沉积法在碳布上直接生长单相Co ₃ O ₄，NiO和Co ₃ O ₄ / NiO纳米复合材料的纳米片阵列。可以通过改变镍来微调成分电沉积溶液中的²⁺ / Co ²⁺比率。纳米片的厚度和平面尺寸也可以被很好地控制。详细研究了尺寸，组成和相对OER活性的影响。优化的纳米片阵列进一步涂覆了NiO层，以实现更高的OER活性。