导电涂层的制备及其在不锈钢生物阳极中的应用

Preparation of conductive coating and its application in stainless steel bioanode

为了提升金属材料作为微生物燃料电池阳极时的生物相容性和耐腐蚀性能,以具有反应活性的酚醛树脂低聚物(PF)作为粘结剂,以超导纳米炭黑(CB)作为导电填料,通过溶液共混法,制备了导电分散液(CB/PF)。优化CB的质量分数和PF的热交联温度后,将既具有高电导率(2.24 S·cm^(-1))又有良好粘结强度的CB/PF用于不锈钢网(SSM)的表面修饰。所得的不锈钢网(CB/PF-SSM)用作微生物燃料电池的生物阳极,能够产生1.1 m A·cm^(-2)的电流密度,比原始不锈钢材料的性能提升了3个数量级,说明修饰涂层具有优异的生物相容性。该电极与空气阴极组装的微生物燃料电池经过长时间运行,能够产生0.45 V左右的电压。经过近70 d的跟踪测试,电压未发生明显下降。耐腐蚀性能测试结果表明,CB/PF修饰的SSM腐蚀电位比原始不锈钢网正移了0.13 V,且生长了生物膜的CB/PF-SSM阳极在高底物浓度时优先发生底物的氧化,说明CB/PF修饰涂层和在其表面生长的生物膜对不锈钢基底具有双重保护作用,提升了不锈钢材料的耐腐蚀性能。为高性能导电涂层的制备和不锈钢基电极的表面修饰提供了一条新途径,所制备的CB/PF-SSM是一种制备方法简单、成本低廉、耐腐蚀的高性能微生物燃料电池阳极材料。

In order to improve the biocompatibility and corrosion resistance of metal materials used as microbial fuel cell anodes,this paper taking reactive phenol-formaldehyde(PF)resin oligomer as binder and superconductive nano carbon black(CB)asfiller,prepared a conductive coating dispersion(CB/PF)via solution blended process.After optimizing the mass fraction of CB and thermal cross-linking temperature of PF,CB/PF with both high conductivity(2.24 S·cm^(-1))and good bonding strength was used for the surface modification of stainless steel mesh(SSM).The modified stainless steel mesh(CB/PF-SSM)was used as a bioanode for microbial fuel cells,and produced a current density of 1.1 m·A cm^(-2),which was three orders of magnitude higher than that of the pristine SSM.This result shows that the modified coating has excellent biocompatibility.The microbial fuel cell of CB/PF-SSM bioanode assembled with air cathode could operate for a long time with a stable voltage of 0.45 V.After nearly 70 days of tracking test,the voltage has not decreased significantly.The corrosion resistance test results show that the corrosion potential of CB/PF modified SSM is 0.13 V higher than that of the original stainless steel mesh,and the corrosion potential of CB/PF-SSM anode grown with biofilm is lower than that of low substrate at high substrate concentration due to the substrate oxidation occuring preferentially.This result suggests that the modified coating CB/PF and the biofilm grown on it have dual protective effects for the stainless steel substrate,which improved the corrosion resistance of the stainless steel material.This paper provides a new approach for the preparation of high-performance conductive coating and the surface modification of stainless steel based electrode.The prepared CB/PF-SSM is a high-performance anode material for microbial fuel cells with advantages of simple preparation method,low cost and high corrosion resistance.