BAND GAP ENGINEERING IN TRANSITION METAL-DOPED PHOSPHATES

Abstract

Nickel manganese phosphate based (NiMnP) materials have potential to be used as the electrode material in advanced energy storage applications, e.g. for supercapacitors, as well as in hybrid supercapacitors. In addition, the bimetallic combination of nickel and manganese synergistically combines advantages of their own roles: nickel’s faradaic charge storage, along with manganese’s pseudocapacitive behaviour, enabling high specific capacities and superb cycling stability. Recent synthesis advancements (e.g., hydrothermal and sono-chemical methods, or their hybridization with conducting materials such as graphene) have enabled much progress toward improving the electrochemical performance of 1D nanomaterials. Charge–discharge retention rates of over 90% are achieved on these hybrid devices, with capacities exceeding 800 F g⁻¹ and energy densities in excess of 64 Wh kg⁻¹. Nanosheet arrays and rodlike structures were found by morphological analysis, which would support high ionic conductivity and fast electron transport. Moreover, the NiMnP materials have optical band gaps in the vicinity of 4.91 eV for optoelectronics and catalysis application. Based on this, NiMnP could be a game–changer to disclose new grounds of possible development of novel sustainable energy systems.