Ag-modified carbon fiber as a stable sensor

Carbon Fiber (CF) electrode has a wide range of applications as an electric field sensor. However, its use is limited because of its poor stability. In this paper, the CF was pretreated by thermal oxidation (400 degrees C, 1 h) to remove surface impurities, resulting in 2.3% mass reduction, which means the increase of effective specific surface area. XRD and EDS confirmed the nano-silver coating was chemically modified on the surface of CF by electroplating. Charging current density differences and Tafel slope showed 6.19 mF cm(-2) and 77 mV dec(-1), respectively, which implied outstanding electrochemical performance. As a sensor, the Ag-modified CF electrode-pair has small potential difference drift of 29 mu V/24 h and excellent response property to low frequency electric field signal, along with lower AC impedance (1.42 Omega@1 Hz) and electrochemical self-noise (1.38 nV/rt (Hz)@1 Hz). The novel Ag-modified CF electrodes provided a potential choice for the design of high-sensitivity marine electric field sensor.