Well-Defined, Nanostructured, Amorphous Metal Phosphate as Electrochemical Pseudocapacitor Materials with High Capacitance

Amorphous micro/nanomaterials are very important members of the noncrystalline materials family and have attracted tremendous interest and exhibited their excellent performance in the application of electrical catalysis and energy storage. The complexity of this research field is limited ultimately by the lack of a facile and practicable strategy to synthesize well-defined ultrathin amorphous nanomaterials. Here, for the first time, we report the random attachment of Co-3(PO4)(2) amorphous nanoplate building blocks into ultrathin nanosheets with dimensions on the micrometer scale. We found the structure of obtained Co-3(PO4)(2) amorphous nanosheet can be converted into nanowire by a split process. On the basis of our observations, an assemble-split mechanism for synthesizing ultrathin amorphous nanostructure is proposed. Furthermore, our strategy is general and can be used to prepare other metal phosphate amorphous ultrathin nanostructures. As a demonstration, the synthesized Co-3(PO4)(2) ultrathin nanowire has been proven to show extraordinary performance as an electrode material for a pseudocapacitor with the specific capacitance of up to 1174 F g(-1), which is much higher than that of crystalline cobalt phosphate and even comparable to that of cobaltous hydroxide nanomaterials.