Formation of Ni_xCo_3-xS₄ hollow nanoprisms with enhanced pseudocapacitive properties

Hollow nanostructures are of great interest for a wide variety of applications. Despite the great advances, synthesis of anisotropic hollow structures is still very challenging. In this work, we have developed a simple sacrificial template method to synthesize uniform Ni_xCo _3-xS₄ hollow nanoprisms with tunable composition. Tetragonal nanoprisms of nickel-cobalt acetate hydroxide precursors with controllable Ni/Co molar ratios are first synthesized and used as the sacrificial templates. After a sulfidation process with thioacetamide (TAA) in ethanol, the solid precursor prisms can be transformed into the corresponding Ni_xCo_3-xS₄ hollow nanoprisms with a well-defined hollow interior. The intriguing structural and compositional features are beneficial for electrochemical applications. Impressively, the resultant Ni_xCo_3-xS₄ hollow prisms manifest a high specific capacitance with enhanced cycling stability, making them potential electrode materials for supercapacitors. NiCo in prism: Uniform hollow Ni _xCo_3-xS₄ prisms with a tunable composition can be facilely synthesized through an efficient self-templating conversion method. Benefiting from the unique structural and compositional features, the as-obtained Ni_xCo_3-xS₄ hollow prisms show excellent electrochemical performance as electrode materials for supercapacitors. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.