3D printed architected polymer/Ag/Pb lattice electrodes: Linking pore geometry to mass transport and electrochemical performance

Boosting effect of ultrasonication on the oxygen evolution reaction during zinc electrowinning

Ag doping to boost the electrochemical performance and corrosion resistance of Ti/Sn–Sb-RuOx/α-PbO2/β-PbO2 electrode in zinc electrowinning

Anodic behavior and microstructure of Al/Pb–Ag anode during zinc electrowinning

Ti/PbO2–TiO2–Ce(NO3)4 electrode for zinc electrowinning was prepared, and the effect of Ce(NO3)4 content on the electrochemical properties of zinc electrowinning anode was studied. Morphology and composition of the Ti/PbO2 electrode before and after polarization were analyzed by SEM and XRD. The corrosion mechanism was investigated by linear sweep voltammetry (LSV), cyclic voltammetry (CV) ,and electrochemical impedance spectroscopy (EIS) analyses. The cell voltage, current efficiency, corrosion rate, anode lifetime, and failure mechanism of Ti/PbO2 and Ti/PbO2–TiO2–Ce(NO3)4 were analyzed by simulating zinc electrowinning experiments. It was found that Ce(NO3)4 promoted the oxygen evolution reaction, and reduced the oxygen evolution potential and energy consumption. The analysis of oxygen evolution peak and reduction peak shows that Ti/PbO2–TiO2–Ce(NO3)4 electrode has good invertibility. In addition, it was found that the addition of Ce(NO3)4 increased the activity of the coating, and Ti/PbO2–TiO2–Ce(NO3)4 (0.5 g L−1) had the best activity. Compared with Ti/PbO2, the cell voltage of Ti/PbO2–TiO2–Ce(NO3)4 (0.5 g L−1) was reduced by 0.15 V, the current efficiency was improved by 4.3%, the corrosion rate was reduced by 0.0331 g A−1 h−1, and the lifetime was improved by 5 h.

Three-dimensional (3D) printing is an emerging technique in the field of biomedical engineering and electronics. This paper presents a novel biofabrication method of implantable carbon electrodes with several advantages including fast prototyping, patient-specific and miniaturization without expensive cleanroom. The method combines stereolithography in additive manufacturing and chemical modification processes to fabricate electrically conductive carbon electrodes. The stereolithography allows the structures to be 3D printed with very fine resolution and desired shapes. The resin is then chemically modified to carbon using pyrolysis to enhance electrochemical performance. The electrochemical characteristics of 3D printing carbon electrodes are assessed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The specific capacitance of 3D printing carbon electrodes is much higher than the same sized platinum (Pt) electrode. In-vivo electromyography (EMG) recording, 3D printing carbon electrodes exhibit much higher signal-to-noise ratio (40.63 ± 7.73) than Pt electrodes (14.26 ± 6.83). The proposed biofabrication method is envisioned to enable 3D printing in many emerging applications in biomedical engineering and electronics.

In this study, the electrochemical and anodic behaviors of MnO2/Pb anodes in electrowinning process were investigated. An accumulative roll-bonding (ARB) method was applied to fabricate MnO2/Pb nanocomposites. The electrochemical properties of the produced anodes were investigated by electrochemical impedance spectroscopy, cyclic voltammetry, electrowinning tests, and scanning electron microscopy. The results indicated that the ARB-process is an appropriate method to develop MnO2/Pb anodes. The produced anodes (Pb–0.5%MnO2-10pass samples) showed a 102% increase in current density compared to pure lead anode. The results of electrowinning tests revealed that Pb–0.5%MnO2-10pass samples had the best anodic performance with a significantly lower corrosion rate, product and electrolyte contamination, slime formation, energy consumption, and a higher current efficiency and consequently, a higher Zn deposition in cathode.

Zinc electrowinning uses an acidic zinc sulfate solution prepared from zinc ore, which contains some other metal ions such as Mn2+. The solution after zinc electrowinning goes back to the solution preparation process, in which the zinc concentration is recovered to the appropriate level, while that of Mn2+ is increased, if no Mn2+ is consumed by anodic deposition in electrowinning cell, which is possible with amorphous RuO2-Ta2O5/Ti anodes [1]. Therefore, the situation that Mn2+ concentration becomes high enough to recover Mn2+ as manganese oxide is expected, and it would resemble the commercial production process of EMD (Electrolytic Manganese Dioxide) that is famous as the positive electrode material of some batteries. For such a novel manganese recovering system in zinc electrowinning, the anode for deposition of MnO2 from zinc electrowinning solution is needed, with which MnO2 is deposited on and harvested from the anode that should be durable for the deposition and harvesting cycle. In this study, we prepared the titanium electrode covered with manganese oxide as the catalytic layer for MnO2 deposition from zinc electrowinning solution, and the obtained electrode was characterized by XRD, SEM, and EDX. The polarization measurement and continuous electrolysis of the anode in Mn2+ containing solutions were also performed to examine the obtained product on the anode and the current efficiency. The manganese oxide coated titanium electrode was prepared by thermal decomposition of the precursor solution containing Mn2+ painted on a titanium substrate which had been degreased in acetone and etched in 10% oxalic acid. The obtained electrode was analyzed by XRD, SEM, and EDX. The anodic polarization of the anode in H2SO4 solution with and without Mn2+ was examined by cyclic voltammetry with a conventional three-electrode cell equipped with a platinum plate counter electrode and an Ag/AgCl reference electrode in saturated KCl solution. Constant current electrolysis was also performed to obtain MnO2 on the anode, and the weight of the anode before and after the electrolysis was measured to know the amount of the product which was characterized by XRD. The electrolytic solution was 2 mol/L H2SO4 + MnSO4 and used at a temperature from 40 oC to 75 oC. The catalytic layer prepared by thermal decomposition was found to be Mn2O3 by XRD measurements. Constant current electrolysis with the anode was carried out under different conditions, in which the typical examples are 40 o C or 75 o C as the electrolyte temperature with electrolysis at 5 mA/cm2 for 30 min. For these conditions, the product on the anode was obtained with the increase of the anode’s weight by electrolysis, and the XRD results showed the diffraction pattern corresponding to MnO2, although the diffraction peak intensity was weak for the product obtained at 40 oC compared to that at 75 oC. The current efficiency for MnO2 deposition was calculated with the assumption that no oxygen evolution occurs, and the results were 17.5% at 40 oC and 70.6% at 75 oC. It was also found that the electrolyte was transparent before constant current electrolysis, which was unchanged by the electrolysis at 75 oC, while that became dark red at 40 oC, implying that Mn3 + is generated at 40 oC and the oxidation of Mn2+ to MnO2 is not completed. More detailed results on the effects of the electrolysis conditions on the obtained product and the current efficiency will be shown in this paper. This work was financially supported by “Kyoto Super Cluster Program” of Japan Science and Technology Agency (JST). Reference [1] T. Zhang, Ph.D. Thesis, Doshisha University (2015).

3D-printed polyacrylamide-based hydrogel polymer electrolytes for flexible zinc-ion battery

A new group of anodic materials and lead–silver alloys, produced in various ways, used as anodes for zinc electrowinning have been investigated. The new anodic materials are composite coatings, deposited on lead–calcium rolled substrates, consisting of a lead matrix and a cobalt–titanium phase. The cobalt and titanium are present in the lead matrix as CoTiO3 nanoparticles. The behaviour of lead–cobalt–titanium anodes during zinc electrowinning was studied by means of galvanostatic polarisation investigations. The processes, occurring on the anodes during zinc electrowinning, have been studied by cyclic voltammetry. The surface morphology of the composite electrodes was investigated by scanning electron microscopy. It has been established that the anodic potentials of the composite electrodes investigated are negligibly higher than those of the classical lead–silver alloy. It has been shown by cyclic voltammetry that the curves of the new electrodes possess the same characteristic peaks as those of pure lead electrode.

Increasing drug-facilitated crimes, mainly sexual assaults have intensified the necessity of accessible and efficient methods for club drugs detection especially in biological matrices and beverages that are served at parties and clubs. The recent development of 3D printing technology has markedly accelerated. One prominent application is the fabrication of wearable electrochemical sensors for the selective and sensitive detection of club drugs such as amphetamine. This class of drug is used as a stimulant in the treatment of conditions including attention deficit hyperactivity disorder (ADHD), narcolepsy, and obesity. Monitoring amphetamine type drugs level in human body is critical due to the risks associated with its possible misuses and related health concerns. By employing the use of 3D printing, makers can create complex and customized sensors specially intended for drug detection. This compliance facilitates integrating diverse type of sensors, thereby improving detection accuracy also. Conventional diagnostic methods are frequently labor-intensive and time-consuming, positioning 3D printed sensors as an innovative approach for real-time monitoring applications. Integrating 3D printing technology in sensor development holds significant potential to transform personalized healthcare by enabling accurate, rapid, and safe detection of amphetamine. This novel study shows the development of a screen-printed paper based electrochemical device with a 3D printed wristband cassette design named "3DP-PWC". This 3D printed paper based wristband cassette (3DP-PWC) features modified electrodes with amphetamine binding aptamer and copper nanoparticles (CuNPs). For electrochemical study, cyclic voltammetry (CV), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) were used and further validated the sensor's performance. Developed sensor demonstrated versatility across various beverage types (alcoholic and non-alcoholic) and biological matrices such as synthetic urine. The developed sensor achieved a low detection limit (LOD) of ~0.02μg/mL with a linear range between 0.01 to 7μg/mL. Promising results were obtained at an optimum response time of approximately 25seconds.

Electrochemical impedance spectroscopy and Raman spectroscopy studies on electrochemical interface between Au(111) electrode and ethaline deep eutectic solvent

Self-assembled monolayers of a hydroquinone-terminated alkanethiol onto gold surface. Interfacial electrochemistry and Michael-addition reaction with glutathione

Predicting the dissolution rate of nonaqueous phase liquids (NAPLs) in groundwater is difficult, as the effects of variable pore and NAPL blob geometry are poorly understood. To elucidate these effects, fluorescence microscopy and digital image analysis were used to quantify the size and location of variably distributed NAPL blobs during dissolution in homogeneous and heterogeneous pore networks etched into silicon wafers. Results show that the dissolution rate constant (expressed as the Sherwood number, Sh) is relatively constant regardless of pore and NAPL blob geometry when the average mass transfer length scale remains constant during dissolution. Results also show that Sh increases with Peclet (Pe) between 2 and 26 and then levels off. The limiting value of Sh reached depends on the average diffusion length scale; this length scale was directly calculated and found to vary depending on the pore and NAPL blob geometry. For example, the average diffusion length scale decreases (and Sh increases) as the pore throat width to grain diameter increases. Last, results show that the volumetric NAPL content (θn) is linearly related to the specific NAPL‐water interfacial area (ait) over much of the dissolution process. However, this relationship depends on the pore and blob size distribution. For example, when multipore blobs control dissolution, the relationship between these parameters will change as smaller blobs dominate dissolution at low θn. These results are important because existing mass transfer correlations do not account for limiting values of Sh that can be obtained at high Pe for the effect of blob or pore geometry on the average diffusion length scale (and therefore on Sh) or for the effect of pore geometry and transient blob size distribution on the relationship between ait and θn.

Printing parameters affect the electrochemical performance of 3D-printed carbon electrodes obtained by fused deposition modeling

The advent of 3D printing technology has spurred innovation, particularly in healthcare and biosensing. One notable application is the creation of wearable biosensors for detecting substances like ketamine, a potent anesthetic and pain reliever with medical and recreational uses. Monitoring ketamine levels is crucial due to potential misuse and health risks. Utilizing 3D printing, manufacturers can produce intricate and customizable wearable biosensors designed for ketamine detection. This flexibility permits the incorporation of various sensor types, enhancing accuracy. Traditional detection methods are often cumbersome, making 3D printing a transformative tool for real-time monitoring. The application of 3D printing in wearable biosensors has the potential to revolutionize personalized healthcare, ensuring the safe and effective usage of ketamine. In this paper 3D printed paper-based wearable aptamer cassette (3DP-PWC) has been developed by immobilizing Ketamine Aptamer on ZnO-NPs electrodes. Electrochemical techniques such as cyclic voltammetry (CV), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS) were employed for validating results. The sensor’s versatility was demonstrated across beverages encompassing both alcoholic and non-alcoholic options. Two prototypes—a bracelet and a pendant—were developed and compared, showing promising results. Here, we reported a 3D-printing paper based wearable aptasensor for the ketamine detection. This pioneering developed sensor showed a low limit detection (LOD) of 0.01 μg/mL (lower than the physiological detection threshold 0.084 μg/mL) with linear-range was between 0.01 and 5 μmL and an optimal response time of 25 s.