Herein, the Taguchi L-9 orthogonal technique has been employed to design the optimised conditions (sulfur source, temperature, reaction time and surfactant) for the preparation of nickel sulfide polymorphs using hydrothermal method. The experimental results demonstrate the temperature dependant phase transition of NiS → Ni₃S₄ → NiS₂ and the prepared nickel sulfide polymorphs exhibit distinctive morphologies of sugar cubes, spherical apple, rose type, aggregated stones, and tubular bacteria type structures. The effect of morphology and crystalline structure on oxygen evolution reaction (OER) has been investigated for the first time where the OER performance follows the order: NiS > NiS₂ > Ni₃S₄. Among the various morphologies of NiS, and NiS₂, the order of OER performance is as follows: NiS_{(sugar-cubes)} > NiS_{(agglomerated stone particles)} > NiS_{(apple shaped)} and NiS_{2(aggregated stoneparticles)} > NiS_{2(rose type)} > NiS_{2(tubular bacteria)} shaped nanostructure.

在本文中，Taguchi L-9正交技术已被用来设计优化的条件（硫源，温度，反应时间和表面活性剂）以使用水热法制备硫化镍多晶型物。实验结果表明，NiS→Ni ₃ S ₄ →NiS ₂的温度依赖性相变，所制得的硫化镍多晶型物具有独特的糖块，球形苹果，玫瑰型，聚集石和管状细菌型结构形态。首次研究了形态和晶体结构对氧释放反应（OER）的影响，其中OER性能遵循以下顺序：NiS> NiS ₂  > Ni ₃ S ₄。在NiS和NiS ₂的各种形态中，OER性能的顺序如下：NiS _（糖块）  > NiS _{（结石颗粒）}  > NiS _{（苹果形）}和NiS _{2（聚集的石颗粒）}  > NiS _{2（玫瑰型）}  > NiS _{2（管状细菌）}形纳米结构。