Highly Effective Self-Propagating Synthesis of Lamellar ZnO-Decorated MnO₂ Nanocrystals with Improved Supercapacitive...

A series of MO (M = Co, Ni, Zn, Ce)-modified lamellar MnO₂ electrode materials were controllably synthesized with a superfast self-propagating technology and their electrochemical practicability was evaluated using a three-electrode system. The results demonstrated that the specific capacitance varied with the heteroatom type as well as the doping level. The low ZnO doping level was more beneficial for improving electrical conductivity and structural stability, and Mn10Zn hybrid nanocrystals exhibited a high specific capacitance of 175.3 F·g^-1 and capacitance retention of 96.9% after 2000 cycles at constant current of 0.2 A·g^-1. Moreover, XRD, SEM, and XPS characterizations confirmed that a small part of the heteroatoms entered the framework to cause lattice distortion of MnO₂, while the rest dispersed uniformly on the surface of the carrier to form an interfacial collaborative effect. All of them induced enhanced electrical conductivity and electrochemical properties. Thus, the current work provides an ultrafast route for development of high-performance pseudocapacitive energy storage nanomaterials.