Kang Xiao

Amorphous Ni(OH)2 @ three-dimensional Ni core–shell nanostructures for high capacitance pseudocapacitors and asymmetric supercapacitors

A complex hydroxide/metal Ni(OH)2@Ni core–shell electrode was developed for a high-performance and flexible pseudocapacitor. Compared to the conventional Ni(OH)2 electrode, the as-prepared amorphous Ni(OH)2@ three-dimensional (3D) Ni core–shell electrode shows a large specific capacitance of 2868 F g−1 at a scan rate of 1 mV s−1 and a good cycling stability (3% degradation after 1000 cycles) at a scan rate of 100 mV s−1. Furthermore, the high rate capability with a specific capacitance of 2454 F g−1 can be achieved at a charge–discharge current density of 5 A g−1. An amorphous Ni(OH)2@3D Ni-AC based asymmetric supercapacitor could be cycled reversibly in the high-voltage region of 0–1.3 V, and the specific capacitance of 92.8 F g−1 at 1 A g−1. This research demonstrates that introduction of a metal core to conventional hydroxide supercapacitor electrodes could open up new opportunities for designing and developing high-performance supercapacitors.

Fabrication of hierarchical flower-like super-structures consisting of porous NiCo2O4 nanosheets and their electrochemical and magnetic properties

In the present work, we demonstrate a facile and cost-effective strategy for synthesizing hierarchical flower-like super-structures consisting of porous NiCo2O4 nanosheets. The morphologies and surface areas of NiCo2O4 samples can be tailored by changing the reaction time. The synthesized NiCo2O4 samples are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and by using an accelerated surface area and porosimetry analyzer (ASAP 2020M). The NiCo2O4 samples exhibit high activity and superior cycling stabilities in ORR. In addition, the magnetic properties of NiCo2O4 samples are also studied in detail.

Double-Shelled CdS- and CdSe-Cosensitized ZnO Porous Nanotube Arrays for Superior Photoelectrocatalytic Applications.

The effective separation and transport of photoinduced electron-hole pairs in photoanodes is of great significance to photoelectrochemical and catalytic performance. Here, a facile and effective two-step strategy is developed to fabricate double-shelled ZnO/CdS/CdSe porous nanotube photoanodes from ZnO nanorod arrays (NRAs). Surprisingly, after the process of the deposition of CdS and CdSe, the ZnO nanorod arrays are partially dissolved, resulting in the formation of ZnO/CdS/CdSe porous nanotube arrays (NTAs). By virtue of their unique porous nanotube structure and cosensitization effect, the ZnO/CdS/CdSe porous NTAs show superior photoelectrochemical water-splitting performance and organic-pollutant-degradation ability under visible light irradiation, as well as excellent long-term photostability.