Sun Xueying,Li Siqi,Liu Rongmei,Sun Xiulun,Liu Xinjie,Li Anran,Li Wen
In this work, we designed a simple hydrothermal synthetic method for a ZnCo-PBA@α-Co(OH) 2 nanosphere@nanosheet material with good electrochemical properties. The obtained material had a specific capacitance of 423.92 F g −1 at 1 A g −1 and a cycling retention ratio of 78.48% after 1000 cycles at 5 A g −1 . A hybrid supercapacitor device (ZnCo-PBA@α-Co(OH) 2 //AC) assembled with activated carbon as the negative electrode had a specific capacitance of 122.4 F g −1 at 1 A g −1 , a cycling retention rate of 73.53% after 5000 cycles at 5 A g −1 , and a very high energy density of 49.13 Wh kg −1 at power density of 1734.0 W kg −1 . The significantly improved electrochemical performance of the ZnCo-PBA@α-Co(OH) 2 nanocomposites can be attributed to the positive synergistic effects of the porous structure of the PBA material and the large specific surface area of the α-Co(OH) 2 nanosheets, on the ion permeability and number of active sites in the reinforcing material; thus, this composite is a potential material for use in future energy storage systems.
Bingbing Cui,Chuanpan Guo,Zhihong Zhang,Guodong Fu
Heterojunction engineering is an acceptable strategy in promoting the separation efficiency of electron/hole pairs in the photochromic process. Here, a series of novel solid-state photochromic ZnCo-PBA@WO 2.72 heterojunctions have been designed and prepared in the current study. The cubic ZnCo-PBA were selected as templates to directly grow WO 2.72 amorphous layer using phosphotungstic acid (PW 12 ) as precursors with the assistance of polyvinyl pyrrolidone (PVP). The as-obtained ZnCo-PBA@WO 2.72 heterojunctions have a core–shell structure and the appropriate band energy promote the UV-generated electrons transport from ZnCo-PBA to WO 2.72 . Consequently, the ZnCo-PBA@WO 2.72 heterojunctions exhibit excellent photochromic performance, converting from white to light-grey in 10 s and finally turning into dark-grey in 60 s under UV lamp stimulation. Meanwhile, the WO 2.72 outer layer was more easily in contact with oxygen in air and thus speeds up the oxidation process of W 5+ to W 6+ , allowing the colored ZnCo-PBA@WO 2.72 heterojunctions to return to their original colorless condition within 15 min. The solid-state photochromic ZnCo-PBA@WO 2.72 heterojunctions was then used as repeatable information storage media, data encryption and decryption based on coloration-decoloration behaviors. This study presents a meaningful way to integrate WO 2.72 with MOFs to expand the range of photochromic materials and further to broaden theirs application in optical devices.
危险品化学品经营许可证（带存储）