科研之友
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摘要
In this study, an environmentally benign strategy was used to fabricate hierarchically ordered mesoporous carbons (HOMCs) using sugarcane bagasse as the scaffold and then activated with nitric acid or carbon dioxide for capacitive deionization (CDI) application. Calcium ions were selected as the model species because of the importance to hard water. The electronic microscopic images show that the HOMCs contain large domains of highly ordered hexagonal arrays of mesopores with 1-D channels and the ordered structures are retained after activation with nitric acid (HOMC-H). In addition, the oxygen and nitrogen content increase in HOMC-H. Different from HOMC-H, a partial distortion of mesostructures with the increase in micropore surface area is observed after physical activation with CO2. The electrochemical performance of HOMCs shows ideal rectangular voltammograms with non-faradic reaction at scan rates of 1-10 mV s(-1) and the specific capacitance of HOMC-H is 1.4-20 times higher than those of as-prepared and CO2-activated HOMCs. The impedance measurement shows good transport of the bulk electrolyte to the electrolyte/electrode interface of HOMC-H with excellent reversibility and ideal capacitive properties. In addition, the specific electrosorption capacity of HOMC-H electrode materials for Ca2+ removal can be up to 115.4 mu mol g(-1) at 1.2 V. The excellent electrochemical performance of HOMC-H is mainly attributed to the increased mesoporous structures and hydrophilic functional groups after chemical activation. Results clearly indicate that the HOMC-H is a promising electrode which could facilitate good charge propagation and fast ion adsorption to treat grey and brown waters.
- 出版日期2015-7
- 单位清华大学
