Electrochromic and Electrochemical Properties of Co3O4 Nanosheets Prepared by Hydrothermal Method

In this paper, Co3O4 nanosheets were prepared by the hydrothermal method. The structure of the material was analyzed by morphological characterization and physical phase analysis, which confirmed the preparation of the product, Co3O4, showing a nanosheet structure. By studying the electrochromic properties of the prepared products, the results show that the transmittance modulation range of the Co3O4 nanosheet is 75% at 780 nm. The coloring response time and bleaching response time is about 3.8 s and 3.4 s, respectively. Electrochemical tests show that the Co3O4 nanosheets have good capacitive properties. Their specific capacitance reaches 1850 F/g when the current density is 1 A/g. When the current density is 5 A/g, the specific capacitance can still maintain 99.6% after 5000 cycles. In addition, Co3O4//CNTs devices can provide a maximum energy density of 79.52 Wh/kg (1 A/g) and a maximum power density of 11,000 W/kg (15 A/g), showing good energy storage capacity. The above data results indicate that the prepared Co3O4 nanosheets can be used as good candidates for supercapacitors. This paper provides a new idea and method for preparing Co3O4 materials.