Controllable 3D Flower-Like Ag-CF Electrodes as Flexible Marine Electric Field Sensors with High Stability

Abstract

Construction of three-dimensional (3D) flower-like nanostructures with controlled morphologies has emerged as an attractive tool by scientists in the marine electric field sensor research field due to their peculiar structural features. Herein, novel 3D flower-like Ag-CF capacitive composite electrodes have been created by an eco-friendly water-bath strategy via AgNO3 as a sliver source and subsequently compounded with carbon fibers (CFs) pretreated by thermal oxidation. A series of electrode samples with various morphologies obtained by modulating different reaction times and temperatures bring about the dominant formation mechanism of these nanostructures and the influence behavior on the CF electrode in detail. Especially, the 3D flower-like Ag-CF electrode shows a large surface area acquired under the conditions of 80 °C and 15 min, which can provide more electroactive sites in electrochemical analysis and exhibit a maximum areal specific capacitance of 619.75 mF·cm–2 at a scanning speed of 10 mV·s–1. This is mainly due to the synergistic behavior of the unique 3D flower-like morphology and the large specific surface area of CFs. Furthermore, a cylinder-shaped Ag-CF sensor is designed, which delivers a superior potential difference of 33.08 μV, a potential difference drift of 18.62 μV/24 h for 30 days, and a self-noise of 0.92 nV/rt (Hz)@1 Hz. In this work, the intriguing synthesis strategy can be a promising facile approach to manufacture the controllable 3D flower-like Ag-CF electrode for electric field sensor applications.

Ag/Reduced Graphene Oxide/Carbon Fiber Composites as Electrodes for Highly Stable and Responsive Marine Electric Field Sensors

“…However, bare CFs cannot respond well to the high-frequency electric field because it decays fast in the high-frequency electric field. The penetration depth of electromagnetic waves in the seawater can be expressed as eq 7 56 = f 252…”

“…Nevertheless, due to the attenuation effect caused by the high conductivity of seawater, the marine electric field signal is extremely weak. It is noted that the amplitude of the electric field E decays exponentially with depth z in the seawater according to eq E = E 0 e − italicbz where b is the absorption coefficient or attenuation constant, which is the reciprocal of the penetration depth. It can be proven that at a low frequency of 10 –3 Hz, the amplitude of the seabed electric field is only 10 –8 V / m , and the signal is quite weak.…”

“…However, bare CFs cannot respond well to the high-frequency electric field because it decays fast in the high-frequency electric field. The penetration depth of electromagnetic waves in the seawater can be expressed as eq δ = 252 f where f is the frequency of electromagnetic waves (Hz). When f = 10 000 Hz , the penetration depth is only 2.52 m. Therefore, the high-frequency signal is weaker and the bare CFs are difficult to respond to.…”

“…According to the relevant literature, the exchange current density (1.0 A/cm 2 ) of metal sliver (Ag) is much higher than that of other commonly used metals . For one thing, the composite active material Ag prevents graphene repacking by acting as a nano space and provides many electroactive sites for ion diffusion/interaction, thereby enhancing the electrochemical and electric-field performance . For another, the generated metal Ag promotes several advantages, such as residual charge accumulation, stable structure, efficient trans-plane ion transport, amplified chemical reactivity, and enhanced ion interaction (hydrophilic surface), which enable the augmented performance of capacitive marine electrodes in enhancing capacitance, fast response, and long-term stability.…”

Construction of a label-free electrochemical immunosensor based on a Co9S8/Co3C@C dual-heterojunction for the detection of diethylstilbestrol

“…Through the contact, electrons are transferred until the work functions are equal. 34,35 Chemical doping, 36 nanostructure engineering, 37 and construction of hybrids 38 are all viable strategies for fulfilling the fabrication of heterostructures. It consequently seems extremely positive to combine alternative construction approaches to create heterostructures.…”