Controllable Synthesis Of Hierarchical Heterostructure Nanomaterial For Their Electrochemical Property

With the rapid development of science and technology and electronic upgrading of products, the rapid increase in the demand for energy has attracted widespread attention. In addition, in recent years, environmental pollution is increasingly serious, which greatly accelerated the high efficient, cleanly, pollution-free of the new energy materials research. The nanomaterials serve as one of the inorganic materials, which is developed in recent years. Due to the unique properties of its own in electricity, thermology, mechanical, optics, magnetism,Particllarly, in catalysis, energy storage(supercapacitor, lithium ion battery), it show a unique advantages compared with the traditional materials.In this paper, we successfully synthesized Zn O Nanofilm, 3D Firecracker-like Zn ONanoarchitectures,Zn Co2O4@Mn O2 core-shell electrode Co Ni2S4 Nanowire Arrays, Zn O@Mn O2@PPy Ternary core-shell Nanorod Arrays. Meanwhile, as-synthesized nanocomposite is directly grown on metal substrate and used as working electrode.We studied the electrochemical properties by electrochemical workstation.1. Ultrathin Zn O nanofilms based on Zn substrate were synthesized through a facile one-pot hydrothermal method. Then this prepared Zn-Zn O integrated electrode was directly used as work electrode to detect glucose and hydrazine in the solution, respectively. Exhilaratingly, the results show that the prepared Zn-Zn O integrated electrode has significant electrocatalytic activity toward the oxidation of glucose and reduction of hydrazine. As a result, Zn-Zn O integrated electrode exhibits a wide linear range from 1 u M to 19.2 m M for the detection of glucose with a low detection limit of 1 u M(S/N=3) and a wide linear range from 0.5 u M to 14.2 m M for the detection of hydrazine with a linear range from with a low detection limit of 0.5 u M(S/N=3). What’s more, the proposed sensor displays excellent selectivity, good stability, and satisfying repeatability.2. A novel 3D firecracker-like Zn O nanoarchitecture was successfully fabricated on a Zn piece via facile, one-step hydrothermal approach without any surfactants. The as-prepared 3D Zn O nanoarchitec- tures/Zn piece are investigated as an integrated electrode to detect hydrazine(HZ) and used as the catalyst for a direct HZ fuel cell. The results show that the 3D firecracker-like Zn O integrated electrode has a high electrocatalysis performance to hydrazine. At the same time, the prepared samples were used for the photocatalytic degradation of methyl orange(MO) aqueous solution under UV-light irradiation. The results exhibit strong UV-light absorption capability, high degradation rate, and greatly enhanced photocatalytic activity toward degradation of methyl orange(MO) aqueous solutions. Therefore, we confirmed that 3D firecracker-like Zn O nanoarchitecture possesses underlying application for the HZ fuel cell and photocatalytic degradation methyl orange.3. Hierarchical Zn Co2O4@Mn O2 core–shell nanotube arrays electrode was developed by a facile two step method. The electrode exhibits high specific capacitance of 1981 F g-1(2.38 F cm-2) at a current density of 5 A g-1 and excellent cycling stability(5000 cycles). Furthermore, a low-cost high-performance asymmetric supercapacitor(ASC) with Zn Co2O4@Mn O2 core–shell nanotube arrays on Ni foam(as positive electrode) and 3D porous α-Fe2O3 on Fe foil(as negative electrode) was successfully designed. The as-designed ASC device with an extended operating voltage window of 1.3 V achieved a specific capacitance of 161 F g-1 at 2.5 m A cm-2 with a maximum energy density of 37.8 Wh kg-1.4. We have successfully in situ grown Co Ni2S4 nanowire arrays on nickel foams through a facile anion-exchange reaction. The electrochemistry tests show that these self-supported electrodes are able to deliver ultrahigh specific capacitance(2424 F g-1 at a current density of 5 m A cm-2), together with a considerable areal capacitance(4.85 F cm-2 at a current density of 5 m A cm-2). Furthermore, a capacitance retention of 86% after 5000 charge-discharge cycles at 5 m A cm-2 is obtained, indicating the excellent cycling stability of the Co Ni2S4 NWAs/nickel foam electrode.5. The Zn O@Mn O2@PPy ternary core-shell nanorod arrays(NRAs) is fabricated through the layer-by-layer process,which involves a simple hydrothermal process and electrochemistry polymerization process. In this process, the incorporation of a highly conductive material(polypyrrole) on the surface of a binary Zn O@Mn O2 core-shell structured composite is adopted to optimize the charge transfer process to further improve the electrochemical performance. Because of enhanced electron transfer capability, charge transfer resistances of the Zn O@Mn O2@PPy ternary core-shell nanorod arrays are reduced and the electrochemical performances are improved. The electrochemistry tests show that these self-supported electrodes are able to deliver ultrahigh specific capacitance(1281 F g-1 at a current density of 2.5 A g-1), together with a considerable areal capacitance(1.793 F cm-2 at a current density of 3.5 m A cm-2). Furthermore, a capacitance retention of 90% after 5000 charge-discharge cycles at 5A g-1 is obtained, indicating the excellent cycling stability of the Zn O@Mn O2@PPy ternary core-shell electrode.