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Various magnetic carbon materials have been employed for nuclide adsorption, yet there exists a research gap concerning their application in electro-adsorption for nuclide removal. In this study, a magnetic carbon nanotube nanocomposite (Fe 3 O 4 /CNT) was successfully synthesized as an electrode material through the hydrothermal method, involving the modification of minute Fe 3 O 4 nanoparticles onto the surface of carbon nanotubes (CNT). Electrochemical assessments revealed that the Fe 3 O 4 /CNT nanocomposite exhibited a higher specific capacitance compared to Fe 3 O 4 and CNT individually. The HRTEM image reveals a heterojunction structure formed directly between Fe 3 O 4 and CNT, which facilitates electron transmission. The Fe 3 O 4 /CNT nanocomposite was utilized as an electrode in a capacitive deionization (CDI) device for U (VI)-contaminated wastewater purification. Experimental results demonstrated that the maximum U (VI) adsorption capacity of the Fe 3 O 4 /CNT electrode reached 287.53 mg/g at 298 K, and the adsorption process conformed to the Langmuir isotherm model. Kinetic analysis further indicated that the adsorption of U (VI) by Fe 3 O 4 /CNT followed a pseudo-second-order kinetic model. Additionally, the Fe 3 O 4 /CNT nanocomposite was transformed into a flowable electrode liquid and applied in a flow-electrode capacitive deionization (FCDI) system for U (VI) removal from aqueous solutions. Leveraging its superparamagnetic properties, the Fe 3 O 4 /CNT flow-electrode within the FCDI system could be rapidly recovered via a straightforward magnetic separation procedure. Notably, after nine consecutive runs of the FCDI device, the Fe 3 O 4 /CNT flow-electrode successfully concentrated a low-concentration U (VI) solution of 120 mg/L into a high-concentration solution of 1230 mg/L, thereby achieving the goal of water resource conservation and reduced storage requirements. [Display omitted] • The high-performance Fe 3 O 4 /CNT nanocomposite was prepared through a one-pot method. • The Fe 3 O 4 /CNT has a higher specific capacitance because of the synergistic effect. • The Fe 3 O 4 /CNT can be used as an electrode for CDI and FCDI devices to remove U (VI). • The Fe 3 O 4 /CNT flow-electrode can be quickly recovered by magnetic separation. [ABSTRACT FROM AUTHOR]

Cavitation erosion, corrosion and synergism behaviors of HVOF sprayed WC-25WB-10Co-5NiCr and MoB-25NiCr coatings were investigated in this study. Conventional WC-10Co-4Cr and Cr 3 C 2 -25NiCr coatings were also characterized for comparison purposes. The cavitation erosion and cavitation-corrosion experiments were carried out in deionized water and 3.5 wt% NaCl solution respectively. The average mass loss rate was defined to assess the destruction of the coating surface. The cavitation erosion resistance and the cavitation-corrosion resistance were adopted to quantitatively analyze the difference of cavitation erosion and cavitation-corrosion performance of the coatings. The potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests were employed to evaluate the corrosion resistance of all the coatings. In addition, the equivalent circuit models were designed to fit the EIS. The cumulative mass loss of all the coatings was measured under the conditions of pure cavitation erosion, pure corrosion and cavitation-corrosion. The total mass loss rate, pure cavitation rate, pure corrosion rate as well as synergistic mass loss rate were calculated to discuss their relative contributions responsible for the material removal. The cavitation-corrosion mechanisms were also discussed by analyzing the eroded surface for all the coatings. [ABSTRACT FROM AUTHOR]

[Display omitted] • The preparation process of the CDI electrode is simplified. • Laser-induced graphene (LIG) can be directly used as a CDI electrode. • LIG electrode is modified by one-step electrodeposition of Co 4 S 3. • The LIG6/Co 4 S 3 -15 presents a high adsorption capacity of 2702.79 mg g−1. • UO 2 2+ adsorption is attributed to the synergistic action of EDLs and pseudocapacitance. It has been proved that capacitive deionization (CDI) technology possesses a significant potential for uranium capture. However, the CDI performance has been limited by the complex preparation process of the electrodes and the poor adhesion between electrode materials and collectors. Here we combine the laser-induced graphene (LIG) and the electrodeposition to develop the LIG/cobalt sulfide (LIG/Co 4 S 3) electrodes with good adsorption performance. The obtained LIG6/Co 4 S 3 -15 electrode has both electrical double layers (EDLs) and pseudocapacitance properties, with a specific capacitance of 24.27 F g−1, which is 1.82 times higher than that of LIG6 (13.36 F g−1). The LIG6/Co 4 S 3 -15 electrode exhibited a high adsorption capacity of 2702.79 mg g−1. The advantages of this electrode preparation method are mainly attributed to the synergistic effect of the following aspects: (i) simplified graphene preparation by avoiding wet chemistry and post-treatment steps; (ii) simplified tedious electrode preparation such as electrode slurry distribution and sheet coating; (iii) the three-dimensional structure of LIG provides not only the conductive network but also the site for Co 4 S 3 nanosheet growth, thus avoiding nanosheet aggregation. The abundant pore structure of the conductive graphene substrate and the layered structure of the Co 4 S 3 nanosheets enable the LIG6/Co 4 S 3 -15 electrode with fast charge/ion transport, high hydrophilicity and superior pseudocapacitance, allowing uranyl (UO 2 2+) to be firstly electrosorbed, then physicochemically adsorbed, and finally electrocatalytically reduced/deposited onto the electrode. This study will offer a simple and environmentally friendly method for the synthesis of electrodes and provide a reference for the design of efficient electroadsorption materials. [ABSTRACT FROM AUTHOR]

3D manipulation of two droplets in a pair of parallel plates configuration with patterned electrodes. • The droplet 3D manipulation was achieved with hybrid forces, namely, asymmetric electrowetting force and electrostatic force. • A numerical model was developed for the quantitative interpretation of the droplet dynamic behavior between two plates. • Both the threshold and the limitation applied voltage for driving the droplet were determined experimentally. In this paper, we demonstrated the droplets three-dimension (3D) manipulation between a pair of parallel liquid-infused membrane plates with patterned electrodes by programmably controlling electrical direct current signals. The asymmetric electrowetting behaviors of droplet between the parallel slippery liquid-infused porous surface (SLIPS) plates configuration were investigated firstly. The droplet tends to move from the higher potential plate to the lower potential plate. The transport of the deionized water droplet in the vertical direction with electrostatic force was investigated in detail subsequently. A model was developed to study the dynamic transport behavior of the droplet movement in the vertical direction. It is found the droplet velocity increases with time, while tends to a maximum value due to the increase of drag force. We also experimentally demonstrated the droplet was driven accelerated from the higher potential plate to the lower one, and the transport time exponentially decreases with the increase of applied voltage. However, note that the excessive applied voltage would cause irregularly jumping of droplets between two plates. The applied voltage range for driving a 0.5 μl droplet was determined experimentally with various parallel-plate spacings. Finally, we demonstrated the 3D manipulation of one droplet and two droplets in two parallel plates configuration with patterned electrodes by the hybrid forces, namely, by asymmetric electrowetting force in the horizontal direction and by electrostatic force in the vertical direction. The 3D droplet manipulation on SLIPS provides a promising solution for high-throughput analysis and integrated device with high density on the digital microfluidic chip. [ABSTRACT FROM AUTHOR]

[Display omitted] • A rich-mesoporous biocarbon (CSKN-15) was synthesized and analyzed. • The ultra-high U-selective electrosorption coefficient from the mixed solution. • The diffusion process of U(VI) into the pores is the key in the electrosorption. • Faradaic reactions were first carefully analyzed in the electrosorption of U(VI). • The formation mechanism of uranium peroxide species was revealed. Constructing the excellent rich-mesoporous carbon and exploring its electrosorption process are keys to promote the electrosorption industrialization of uranium. In this work, we develop a rich-mesoporous biocarbon by using alkali-thermal-pyrolysis and ammonia low-temperature plasma, and then systematically investigate its electrosorption kinetics and mechanism of U(VI) considering a series of Faradaic side reactions. After the above treatment, the electrosorption efficiency of U(VI) onto biocarbon improves from 49.75% to 94.45%, and the ultra-high U-selectivity coefficient (S U/M) is higher than 120 from the mixed solution. The kinetic diffusion process of U(VI) into the pores is crucial, even in different water systems. Importantly, Faradaic side reactions are proved to be non-negligible factors in the electrosorption of uranium. Especially, the oxygen reduction at the cathode can convert dissolved oxygen into H 2 O 2 , which oxides the amorphous electro-reduced U(V, IV) to U(VI), and finally forms crystalline uranium peroxide species. To sum up, this work not only offers an excellent uranium-selectivity electroadsorbent, but firstly confirms the influence of Faradaic side reactions that has been ignored in the current electrosorption of uranium. [ABSTRACT FROM AUTHOR]

[Display omitted] • Modified carbon black (CB) by O 2 plasma technology for improving CDI capacity. • The effect and mechanism of plasma modified CB (PCB) to improve CDI were explored. • PCB improved the salt removal performance 6.9 times that of the original CB (OCB) • PCB can be applied to improve CDI of various active materials. • PCB has universal applicability in purifying brine, heavy metals and radionuclides. Previous research on capacitive deionization (CDI) mainly focuses on electrode active materials, while the research on conductive additive and their modification for improving CDI performance are rarely reported. In this work, we mainly investigate the effect and mechanism of oxygen (O 2) plasma-modified carbon black (PCB) to enhance CDI performance. The CB treated with O 2 plasma at 100 W for 10 min (CB-100 W-10 min) was assembled with activated carbon (AC) to form a CB-100 W-10 min/AC electrode with excellent desalination performance (32.54 mg g−1), 6.9 times that of the original CB/AC electrode (OCB/AC, 4.91 mg g−1). The roles of the specific surface area, hydrophilicity, electrical conductivity, and specific capacitance of CB in enhancing the performance of CDI were explored, and the interaction mechanism between H 2 O molecules and CB was investigated using molecular dynamics (MD) simulations. The advantages of PCB are mainly attributed to the synergy of the following aspects: (i) The excellent three-dimensional network structure acts as a "bridge" between activated carbon and increases the contact sites for allowing more PCB and AC to participate in the electrosorption process; (ii) Shorter electron transmission paths and more electron transmission channels between PCB and AC promote the electrosorption rate; (iii) High surface roughness and oxygen-containing functional groups of PCB boost hydrophilicity and dispersibility. Interestingly, we found that PCB possesses universal applicability in the enhancement of deionization performance of various active materials for purification of brine, heavy metals and radionuclides. This work unprecedentedly applies plasma technology to the modification of conductive additive, providing new ideas for material modification and improvement of CDI technology. [ABSTRACT FROM AUTHOR]

Melt-blown polypropylene electret fabric prepared by hydrocharging technique has excellent filtration performance. However, its filtration mechanism and charge characteristic have not been clarified yet. This paper reports some new investigating results. Its filtration efficiency is correlated to its trapped charge. To achieve high filtration performance, deionized water with high resistivity must be adopted; both water spray pressure and drying temperature need to be kept within a suitable range. The positive and negative charges coexist and exhibit the characteristic of electric double layer in the MBPP electret fabric. In addition, the surface potential is significantly lower than the corona charged electret fabric. • It is proved that the excellent filtration performance is correlated to the trapped charge in the hydrocharged MBPPEF. • It is reported that the hydrocharging processing conditions can influence the charge trapped performance in MBPPEF, which affects FE. • It is firstly found out that the positive and negative charges coexist in the hydrocharged MBPPEF. [ABSTRACT FROM AUTHOR]