Display omitted
•A novel enzyme-free glucose sensor was fabricated by first using Ni(OH)2@PEDOT-rGO as electrode material.•Ni(OH)2@PEDOT-rGO was synthesized by a facile and easy-to-control ...electrodeposition method.•The sensor exhibited ultrafast response time, wide linear range, low detection limit.•It exhibited superb specificity, good stability and successfully for real sample analysis.
The novel nanocomposite of Ni(OH)2 nanoparticles over reduced graphene oxide and poly (3,4-ethylenedioxythiophene) hybrid film (Ni(OH)2@PEDOT-rGO) have been successfully fabricated via a facile, scalable and easy-to-control electrodeposition method. The characterization results of scanning electron microscope (SEM) and electrochemical techniques show that Ni(OH)2 nanoparticles with an average particle size about 10nm are uniformly deposited on PEDOT-rGO hybrid film with rough surface and reveal outstanding performance for detecting glucose. The enzyme-free glucose sensor exhibits an ultrafast response time (<1s), a wide linear range (0.002–7.1mM), a low detection limit (0.6μM) and a high sensitivity (346μAmM−1cm−2). Moreover, the sensor also displays superb selectivity, excellent reproducibility and good stability. The outstanding properties of the sensor may be attributed to the synergistic effect of Ni(OH)2 nanoparticles possessing high electro-catalysis activity and PEDOT-rGO having well conductivity. More importantly, the sensor was successfully used to determine glucose in the real samples. In addition, the mechanism of electrodeposited PEDOT-rGO and glucose oxidase was investigated.
The propensity of Zn‐metal anodes to form non‐uniform or dendritic electrodeposits is bound up with the nature of the electrode surface. However, the effect of surface structure on the inherent ...nucleation and deposition of Zn is not yet well understood. Here, the surface structure of a Zn‐metal anode is reconstructed with Sn‐crystal textures via a facile chemical displacement reaction. Compared to the bare Zn, the high‐affinity Zn binding sites of Sn afford lower deposition energy barrier, which promotes deposition kinetics. What is more, a Sn‐textured surface with moderate Zn affinity but high average surface energy ensures a better wettability from the deposits, leading to the lateral growth of Zn crystals. The resultant Sn‐textured Zn‐metal anode exhibits an extremely low voltage hysteresis of 20 mV and achieves a prolonged cycling stability over 500 h cycles without dendrite formation. This work provides new insights into the crystal‐texture‐dependent Zn electrodeposition process and offers direction for direct surface texturing to better stabilize Zn‐metal anodes with improved reversibility.
The surface of a Zn‐metal anode is reconstructed with Sn‐crystal textures via a facile chemical displacement reaction. Such a Sn‐textured surface not only endows a reduced Zn deposition energy barrier but also regulates the lateral growth of Zn crystals, which promotes dendrite‐free electrodeposits and leads to the achievement of an extremely low voltage hysteresis of 20 mV and prolonged cycling performance over 500 h.
With advantages such as high theoretical capacity, low cost, and nontoxicity, Zn metal has been widely investigated as an anode for aqueous batteries. However, the problems of dendrite formation and ...sustained corrosion originating from severe interfacial side reactions and uncontrolled Zn electrodeposition in aqueous electrolytes significantly slows down the practical application of Zn metal anodes. To address these issues, herein, an anti‐corrosion elastic constraint (AEC) is introduced that is built with nanosized TiO2 and polyvinylidene fluoride (PVDF) matrix to Zn anode, where the PVDF layer serves as an elastic H2O/O2‐blocking layer and the decorated TiO2 nanoparticles assist uniform Zn electrodeposition. With this corrosion‐inhibition and electrodeposition‐redirection coating, the electrodeposition consistency and thermodynamic stability of the Zn anode are significantly improved, enabling a long‐term stable plating/stripping performance for 2000 h with an ultralow overpotential (<50 mV) and a high average Coulombic efficiency (>99.4%) for 1000 cycles without obvious dendrite formation. Even at a high current density of 8.85 mA cm−2 with limited Zn supply (DODZn = 60%), stable Zn deposition is achieved over 250 h. When coupled with a MnO2 cathode, the AEC‐Zn anode shows a remarkably enhanced full‐cell cycling stability, indicative of high reliability of aqueous Zn batteries for practical application.
An anti‐corrosion elastic constraint is developed to redirect the Zn electrodeposition for aqueous zinc‐ion batteries. With this corrosion‐inhibition and electrodeposition‐redirection coating, the electrodeposition consistency and thermodynamic stability of Zn anodes are significantly improved, enabling a long‐term stable plating/stripping performance for 2000 h with an ultralow overpotential (<50 mV) and a high Coulombic efficiency (>99.4%) for 1000 cycles.
Dynamic windows, which electronically switch between clear and dark states on demand, save energy in buildings and automobiles by minimizing the lighting, heating, and cooling costs. In this study, ...we design dynamic windows by combining reversible metal electrodeposition (RME) and electrochromism, two promising approaches for optoelectronics. These hybrid dynamic windows tint on both electrodes. Reversible Bi and Cu electrodeposition is elicited on the working electrode, while an electrochromic cobalt hexacyanoferrate thin film darkens on the counter electrode. By facilitating plane parallel ion diffusion and dual tinting, this architecture enables dynamic windows to switch more rapidly than devices based on traditional RME schemes. We demonstrate that 25 cm2 devices switch with 58% optical contrast between a transparent and a color-neutral dark state in 20 s. Moreover, these hybrid dynamic windows switch 1000 times without significant degradation in optical performance.
Electrocatalysts with low overpotential and high stability are highly demanded in water-splitting system. The efficiency of water-splitting is largely restricted by the oxygen evolution reaction ...(OER). Here, we developed a two-step method to prepare 3D porous material through chemical vapor deposition and electrodeposition combined with the first-principles calculations. Ultrathin α-Co(OH)2 nanosheets grown on the combined substrate of N-doped carbon nanotubes (NCNTs) and nickel foam were fabricated to investigate their electrochemical behaviour. Because of the characteristics of the ultrathin, microporous α-Co(OH)2 and its derivatives, the 3D Co(OH)2@NCNTs@NF exhibits outstanding performance as a bifunctional catalyst for water-splitting. The overpotentials to achieve 10 mA cm−2 current density in 1 M KOH for OER and hydrogen evolution reaction (HER) are 270 mV and 170 mV, respectively. The as-prepared material exhibits superior stability, which generate 10 mA cm−2 current density in overall water-splitting over 600 h without obvious degradation in 1 M KOH at voltage of 1.72 V vs. RHE. The first-principles calculations reveal that the N-doping not only can effectively enhance the interaction between the substrate and active material (CoOOH), but also modulate the electronic structure of CoOOH to speed up the O2 releasing during the OER.
Display omitted
•3D binder-free catalyst was prepared by CVD and electrodeposition.•The Co(OH)2@NCNTs@NF possesses open porous structure.•The Co(OH)2@NCNTs@NF exhibits high activity and stability in water-splitting.
•Cyclic voltammetry experiments of the additive-free, chloride-based Zn-Mn electrolytic bath were performed to observe its redox behaviour.•Optimum current density range for electrodeposition was ...obtained through potentiostatic studies and Hull cell electrodeposition experiments.•Zn-Mn alloy coatings were obtained through direct and pulsed current electrodeposition and their microstructure, composition and corrosion properties were studied and compared.•Electrochemical impedance spectroscopy was performed on selected DC and PC deposited coatings to study and compare their corrosion mechanisms.•PC deposited coatings at high pulse frequency and low pulse duty cycle showed remarkable improvement in corrosion resistance as compared to DC coatings.
Electrodeposited Zn-Mn alloy coatings are known to provide excellent corrosion resistance to steel due to their ability to form compact corrosion products when exposed to corrosive media. However, obtaining good quality coatings using conventional direct current (DC) electrodeposition from additive free baths is challenging. Pulsed current (PC) deposition has been reported for various Zn based alloy systems to obtain coatings with superior corrosion resistance properties. In this work, Zn-Mn coatings containing up to 9.2 wt. % Mn were electrodeposited on steel from additive-free chloride electrolytes using both DC and PC electrodeposition. Cyclic voltammetry, potentiostatic measurements, Hull cell experiments and SEM-EDS studies indicated good quality DC deposited Zn-Mn coatings in the current density range of 40-60 mA cm−2 with clustered plate morphology at low and cauliflower morphology at higher current densities. PC deposited coatings showed increased Mn contents and improved corrosion rates. The coating deposited at a low duty cycle and a high frequency showed a fine and compact microstructure with the highest Mn content of 9.2 wt. %. XRD studies showed a complete change in phase composition from a monophasic η-Zn-Mn coating with DC to a monophasic ε-Zn-Mn with PC deposition. Electrochemical impedance analysis revealed porous corrosion products in DC coating, whereas the PC coating formed a compact corrosion product which inhibited the dissolution of Zn and Mn, thus providing higher resistance to corrosion. XRD analysis of the samples after corrosion confirmed the presence of zinc hydroxy chloride (ZHC) as a corrosion product. In summary, PC electrodeposited Zn-Mn coatings provided superior corrosion resistance than those obtained through DC.
The electrodeposition of foreign metals on a platinum (Pt) electrode can be used to alter the electrochemical properties of the modified electrode. The current study employed in situ scanning ...tunneling microscopy (STM) to characterize the spatial structures of a monolayer and multilayer lead (Pb) electrodeposited on an ordered Pt(100) electrode in 0.1 M perchloric acid (HClO4) with and without formic acid under potential control. The Pt(100) bead crystal used in this study was pretreated by a modified annealing and quenching method, producing a long-range ordered, unreconstructed (1 × 1) surface. The underpotential deposition (UPD) of Pb on the Pt(100) electrode resulted in a pair of sharp and reversible peak at 0.5 V (vs. Ag/AgCl), prior to the bulk deposition at E < -0.45 V in 0.1 M HClO4 + 1 mM Pb(ClO4)2. Cyclic potential sweeping in the UPD regimes resulted in a stable voltammogram, but bulk Pb deposition led to varying morphologies of the profiles. Atomic resolution STM images were obtained to reveal a well-ordered Pt(100)-(√2 × √2)R45°-Pb structure and elongated rows of Pb aggregates and local (√2 × 2√2) R45° in the initial and final stages of Pb UPD, respectively. Bulk Pb deposition at E < -0.5 V led to a crystalline Pb film, but a roughened Pt(100) surface was imaged after the Pb deposit was anodically stripped. The activity of the Pt(100) electrode toward formic acid oxidation was nearly tripled after being modified with a sub-monolayer of Pb, and increased by another 20 % when it was loaded with multilayer Pb.
The void-free deposition of small-sized and high-aspect ratio interconnect structures requires stronger suppressors than conventional polyethers. In this work, thioether was introduced into polyether ...to develop novel suppressors with improved adsorption on electrode. The structure of thioether-modified polyether can be easily tailored by choosing proper polyether and thiol compound, thus providing a simple way to regulate electrochemical properties of the suppressor. The electrochemical and copper filling performance related to the molecular structure of novel suppressors were systematically investigated. Thioether-modified polyether, which retains the strong polarizability of typical suppressor and exhibits high resistance to accelerator desorption, can significantly suppress copper deposition on feature sidewalls. This enabled defect-free filling of narrower features at a concentration much lower than the typical usage concentration of suppressor. The modified polyethers with ethylene-propylene-ethylene (EPE) oxide triblock ether chains exhibited higher polarization strength and concentration dependence, facilitating the higher deposition current at the bottom during filling. The length and block ratio of ether chain further influenced the anti-desorption ability of the modified polyether, thereby impacting their suppression on sidewalls, which is crucial in filling process. The convenient structural adjustments for thioether-modified polyether, combined with the derived structure-property relationship, contribute to the development of new suppressors with strong adsorption performance.
For practical rechargeable aqueous zinc-ion batteries, the long-term cycling stability of the zinc anode remains significantly constrained by its low utilization efficiency and the persistent ...challenge of hydrogen evolution. This study demonstrates the fabrication of ultrathin zinc electrodes with a robust Zn (002) texture while ensuring an adequate supply of zinc metal for use as an anode material. This approach effectively suppresses the tendency of zinc atoms to undergo deposition transformation due to dislocation-induced phenomena. Compared to zinc foils with higher deposition amount, the ultrathin Zn anode exhibits enhanced resistance to dendrite growth and interfacial side reactions. Assembled symmetrical cells based on this ultra-thin Zn anode show a cycle life of 1750 h (1 mAcm−2, 0.5 mAhcm−2), maintaining stable cycling for over 100h even at a high depth of discharge (DOD) of 46.23%. Additionally, the full cell couple with V10O24 exhibits a high initial capacity of 429.6 mAh g−1 and a capacity retention of 75.8% after 1000 cycles.
Display omitted
•Preventing Zn dendrite formation during cycling by precisely controlling the deposition amount.•Synthesis of ultrathin, strong Zn (002) textured zinc anodes to achieve high utilization, cycling at 46 % DOD for over 100 h.•Elucidates the mechanism underlying the influence of deposition amount on zinc anode performance.
