Electrochemical reduction of dissolved oxygen in seawater on metals is of great importance for corrosion studies.The present paper studied cathodic reduction of dissolved oxygen on Q235 carbon steel in 3.5% sodium chloride(NaCl) solutions by cyclic voltammetry(CV),electrochemical impedance spectroscopy(EIS),rotating disk electrode(RDE) and rotating ring-disk electrode(RRDE).The cyclic voltammetric results demonstrated the cathodic process on Q235 carbon steel in O2-saturated 3.5% NaCl solution contains three reactions:dissolved oxygen reduction,iron oxides reduction and hydrogen evolution.The peak potential of oxygen reduction reaction(ORR) is -0.85 V vs Ag/AgCl,3 molL-1 KCl.The EIS results indicated that the ORR occurring on Q235 carbon steel is a 4-electron process and that no finite diffusion is caused by the intermediate of H2O2 produced by ORR.The RDE and RRDE voltammograms confirmed the EIS results and it was found that the number of transferred electrons for ORR was nearly 4,i.e.,dissolved oxygen reduced to water.
沉积物微生物燃料电池(sedimentmicrobialfuelcells,SM FC s),是一种基于沉积物环境体系,利用其中微生物的催化作用,将有机物中的化学能直接转变为电能的装置。首先介绍了SM FC s的工作原理,突出了微生物的作用。接着从电极本身和环境两方面综述了SM FC s的性能制约因素及改进措施,前者包括电极材料、电极设计、外加动力控制、外加电路控制等,后者包括有机物的供应、氧浓度、温度、电导率等。最后介绍了SM FC s在传感器供电方面的应用实例。
