Abstract:

Oxidants of nitric acid and acidic potassium dichromate were used to modify anode carbon cloths. Modification was completed by first putting the carbon cloth into nitric acid or acidic potassium dichromate at a given temperature, soaking for 30 min and then rinsing with de-ionized water until no variation in pH and finally putting into a vacuum dryer, drying for 12 h. Fourier transform infrared spectroscopy measurements indicated that many hydroxyls and carboxyls were attached on the carbon cloth surface after modification. SEM results showed that the surface of carbon cloth became rougher than the unmodified one. In addition, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) measurements demonstrated that both modified anodes had excellent electrochemical properties. Using the modified carbon cloths as microbial fuel cell (MFC) anodes respectively, such MFCs yielded maximum power densities of 291.11 mW·m^-2 and 438.08 mW·m^-2, 21% and 82% higher than that of the MFC with unmodified carbon cloth anode respectively.

Key words: fuel cell, anode, oxidation, nitric acid, biocatalysis

摘要：

浓HNO₃和酸性K₂Cr₂O₇都具有一定的氧化性,分别利用浓HNO₃和酸性K₂Cr₂O₇对阳极碳布进行氧化改性处理。通过红外光谱测试显示,碳布表面附着了羟基(—OH)和羧基(—COOH)。通过扫描电镜观察,碳布经过氧化改性后表面明显变粗糙。同时,循环伏安曲线(CV)和交流阻抗曲线(EIS)测试表明,经过改性后的碳布具有良好的电化学特性。分别以经过浓HNO₃和酸性K₂Cr₂O₇改性处理后的碳布作为微生物燃料电池(MFC)的阳极,获得的最大功率密度分别为291.11 mW·m^-2和438.08 mW·m^-2,比未经过改性处理的碳布阳极的功率密度分别提升了21%和82%。

关键词: 燃料电池, 阳极, 氧化, 硝酸, 生物催化