Bismuth telluride, a highly efficient thermoelectric material, stands out for applications around room temperature in wearable devices. By harnessing the thermal gradient established between the human body and ambient temperature, we can generate useable electricity. Notably, bismuth telluride nanostructures exhibit significantly lower thermal conductivities compared to their bulk counterparts. As a result, the thermoelectric efficiency achieved is notably higher. Our research focuses on developing efficient nanostructured materials based on bismuth telluride inside a flexible substrate made of polyester. We employ scalable methods, such as template-assisted electrochemical deposition, to fabricate these nanostructures. In this study, we present an approach to the development of flexible nanostructured thermoelectric materials. Despite using a reduced quantity of active material, our electrochemically deposited nanostructures inside a flexible template demonstrate a remarkable performance. They exhibit 24 % of the Power Factor reported for conventional electrochemically fabricated Bi2Te3 thin films, and notably, they even surpass the Power Factor reported for flexible Bi2Te3-based inks used in the creation of flexible generators. This achievement underscores the potential of our method in the advancement of efficient, flexible thermoelectric devices.

Conductive metal-organic frameworks (cMOFs) offer high porosity and electrical conductivity simultaneously, making them ideal for application in chemiresistive sensors. Recently, incorporating foreign elements such as catalytic nanoparticles into cMOFs has become a typical strategy to enhance their sensing properties. However, this approach has led to critical challenges, such as pore blockage that impedes gas diffusion, as well as limited improvement in reversibility. Herein, single-atom catalyst (SAC)-functionalized cMOF is presented as a robust solution to the current limitations. Facile functionalization of SACs in a cMOF can be achieved through electrochemical deposition of metal precursors. As a proof of concept, a Pd SAC-functionalized cMOF is synthesized. The Pd SACs are stabilized at the interplanar sites of cMOF with Pd-N4 coordination while preserving the porosity of the MOF matrix. Notably, the microenvironment created by Pd SACs prevents irreversible structural distortion of cMOFs and facilitates a reversible charge transfer with NO2. Consequently, the cMOF exhibits a fully recoverable NO2 response, which was not previously attainable with the nanoparticle functionalization. Additionally, with the combination of preserved porosity for gas diffusion, it demonstrates the fastest level of response and recovery speed compared to other 2D-cMOFs of this class.

We recommend best practices for the recovery of cobalt from LiCoO2 (LCO) lithium-ion battery (LIB) cathodes by (i) leaching using green deep eutectic solvents (DES) and (ii) subsequent electrodeposition, through a case study of the choline chloride (ChCl):ethylene glycol (EG) DES. DES physical properties (conductivity, viscosity, and surface tension) were tailored by varying the composition between mole ratios of 1:2 and 1:5 (ChCl:EG). Examined along with leaching process parameters (temperature, duration), increasing the fraction of hydrogen bond donors (HBDs) decreased DES surface tension and enhanced leaching. Complete Co recovery was achieved using 1:5 ChCl:EG DES at 160oC and 48 hours. Leaching temperatures >160oC are discouraged due to DES thermal degradation. The electrodeposition process was optimized for selective Co recovery with high faradaic efficiency.  The leaching ability of the DES was antithetical to the stability of electrodeposition cell components and required operational parameter adjustment to minimize degradation. The optimized system (copper cathode and stainless-steel anode) employing 1:5 DES leachate exhibited a faradaic efficiency of ~80 %, specific Co recovery of ~0.8 mg hr-1 cm-1 at 50 oC and evidence of uniform deposition. DES surface tension is a key descriptor of metal recovery, and guidelines are presented to maximize selective Co recovery.

Lab-made biosilica (SiO2) nanoparticles were obtained from waste biomass (rice husks) and used as eco-friendly fillers in the production of nickel matrix composite films via the co-electrodeposition technique. The produced biosilica nanoparticles were characterized using XRD, FTIR, and FE-SEM/EDS. Amorphous nano-sized biosilica particles with a high SiO2 content were obtained. Various current regimes of electrodeposition, such as direct current (DC), pulsating current (PC), and reversing current (RC) regimes, were applied for the fabrication of Ni and Ni/SiO2 films from a sulfamate electrolyte. Ni films electrodeposited with or without 1.0 wt.% biosilica nanoparticles in the electrolyte were characterized using FE-SEM/EDS (morphology/elemental analyses, roundness), AFM (roughness), Vickers microindentation (microhardness), and sheet resistance. Due to the incorporation of SiO2 nanoparticles, the Ni/SiO2 films were coarser than those obtained from the pure sulfamate electrolyte. The addition of SiO2 to the sulfamate electrolyte also caused an increase in the roughness and electrical conductivity of the Ni films. The surface roughness values of the Ni/SiO2 films were approximately 44.0%, 48.8%, and 68.3% larger than those obtained for the pure Ni films produced using the DC, PC, and RC regimes, respectively. The microhardness of the Ni and Ni/SiO2 films was assessed using the Chen-Gao (C-G) composite hardness model, and it was shown that the obtained Ni/SiO2 films had a higher hardness than the pure Ni films. Depending on the applied electrodeposition regime, the hardness of the Ni films increased from 29.1% for the Ni/SiO2 films obtained using the PC regime to 95.5% for those obtained using the RC regime, reaching the maximal value of 6.880 GPa for the Ni/SiO2 films produced using the RC regime.

The constantly evolving environment imposes increasingly stringent demands on the mechanical qualities of materials employed for absorbing electromagnetic waves (EMWs). Therefore, there is an urgent need for advanced materials capable of efficiently absorbing EMWs and withstanding harsh electromagnetic conditions. In this study, the electrodeposition method was effectively used to synthesize nickel-cobalt layered double hydroxides (NiCo-LDHs) in a controlled manner on a composite structure of carbon nanotubes and carbon foam, creating an exquisite construction. The manipulation of the electrodeposition time facilitated the regulation of the density of the layered structure within the composite material, thereby significantly enhancing its polarization relaxation performance. Increased defect sites and interface polarization enhance impedance matching and the attenuation constant, resulting in greatly improved absorption performance. The optimized sample demonstrated exceptional wave-absorbing performance in comparative experimental analysis, attaining a maximum reflection loss of -58.18 dB. It also has an effective absorption bandwidth of 5.36 GHz at a wavelength of 2.28 mm. The exceptional isolation effect of LDH, coupled with the outstanding insulation ability of the porous carbon skeleton, confers remarkable corrosion resistance and thermal insulation performance on the composite material. Hence, this discovery offers novel insights into designing environmentally tolerant absorbent materials.

Electrocatalytic nitrate reduction reaction presents a promising avenue for environmentally friendly ammonia (NH3) synthesis and wastewater treatment. An essential aspect to consider is the meticulous design of electrocatalysts. This study explores the utilization of a Ni-Co alloy nanosheet-decorated three-dimensional titanium dioxide (3D-TiO2) nanobelts electrodeposited on titanium meshes (NixCoy@TiO2/TM) for efficient electrocatalytic NH3 production. The optimized Ni1Co3@TiO2/TM electrode achieves a significant NH3 yield of 676.3 ± 27.1 umol h-1 cm-2 with an impressive Faradaic efficiency (FE) of 95.1 % ± 2.1 % in a 0.1 M KOH solution containing 0.1 M NO3- at -0.4 V versus the reversible hydrogen electrode. Additionally, the electrode demonstrates exceptional electrochemical activity for NH3 synthesis in simulated wastewater, delivering an outstanding NH3 yield of 751.6 ± 44.3 umol h-1 cm-2 with a FE of 96.8 % ± 0.4 % at the same potential of -0.4 V. Moreover, the electrode exhibits minimal variation in current density, NH3 yields and FEs throughout the 24-h stability test and the 20-cycle test, demonstrating its excellent stability and durability. This study offers a straightforward electrodeposited approach for the development of 3D-nanostructured alloys as catalysts for NH3 electrosynthesis from nitrates at room temperature.

Vertical architectures for organic electrochemical transistors (OECTs), due to their submicrometer channel lengths, have presented themselves as a straightforward design approach for achieving high gm/τ ratios, a figure of merit that assesses the performance of the devices by virtue of their transconductance (gm = dID/dVGS) and switching time constant (τ). However, as the practical limitations of the geometries are overcome, the influence of parasitic phenomena becomes more dominant and limits the performance of the device. One approach to reduce the detrimental effects of parasitic resistance in the drain-source circuit is to use a four-point sourcing technique. Here, vertical OECTs are fabricated with four-point structures to approach the intrinsic limit of these devices. It is shown that this approach improves the saturation behavior of the devices, closing the gap between measured gm and intrinsic transconductance gmi at their peak values. Overall, the results discussed here provide insight into the effects of parasitic resistance on OECTs, which in contrast to field-effect transistors, are not as extensively documented.

Heteroatom-doped electrodes offer promising applications for enhancing the longevity and efficiency of vanadium redox flow battery (VRFB). Herein, we controllably synthesized N, P co-doped graphite fiber electrodes with conductive network structure by introducing protonic acid and combining electrodeposition and high temperature carbonization. H2SO4 and H3PO4 act as auxiliary and dopant, respectively. The synergistic effect between N and P introduces additional defect structures and active sites on the electrodes, thereby enhancing the reaction rate, as confirmed by density functional theory calculations. Furthermore, the conductive network structure of carbon fibers improves electrode-to-electrode connectivity and reduces internal battery resistance. The optimized integration of these strategies enhances VRFB performance significantly. Consequently, the N, P co-doped carbon fiber modified graphite felt electrodes demonstrate remarkably high energy efficiency at 200 mA cm-2, surpassing that of the blank battery by 7.9 %. This integrated approach to in-situ controllable synthesis provides innovative insights for developing high-performance, stable electrodes, thereby contributing to advancements in the field of energy storage.

Herein, a heterogeneous structure of Ni-Mo catalyst comprising Ni4Mo nanoalloys decorated on a MoOx matrix via electrodeposition is introduced. This catalyst exhibits remarkable hydrogen evolution reaction (HER) activity across a range of pH conditions. The heterogeneous Ni-Mo catalyst showed low overpotentials only of 24 and 86, 21 and 60, and 37 and 168 mV to produce a current density of 10 and 100 mA cm-2 (η10 and η100) in alkaline, acidic, and neutral media, respectively, which represents one of the most active catalysts for the HER. The enhanced activity is attributed to the hydrogen spillover effect, where hydrogen atoms migrate between the Ni4Mo alloys and the MoOx matrix, forming hydrogen molybdenum bronze as additional active sites. Additionally, the Ni4Mo facilitated the water dissociation process, which helps the Volmer step in the alkaline/neutral HER. Through electrochemical analysis, in situ Raman spectroscopy, and density functional theory calculations, the fast HER mechanism is elucidated.

Zinc-air batteries employing non-Pt cathodes hold significant promise for advancing cathodic oxygen reduction reaction (ORR). However, poor intrinsic electrical conductivity and aggregation tendency hinder the application of metal-organic frameworks (MOFs) as active ORR cathodes. Conductive MOFs possess various atomically dispersed metal centers and well-aligned inherent topologies, eliminating the additional carbonization processes for achieving high conductivity. Here, a novel room-temperature electrochemical cathodic electrodeposition method is introduced for fabricating uniform and continuous layered 2D bimetallic conductive MOF films cathodes without polymeric binders, employing the organic ligand 2,3,6,7,10,11-hexaiminotriphenylene (HITP) and varying the Ni/Cu ratio. The influence of metal centers on modulating the ORR performance is investigated by density functional theory (DFT), demonstrating the performance of bimetallic conductive MOFs can be effectively tuned by the unpaired 3d electrons and the Jahn-Teller effect in the doped Cu. The resulting bimetallic Ni2.1Cu0.9(HITP)2 exhibits superior ORR performance, boasting a high onset potential of 0.93 V. Moreover, the assembled aqueous zinc-air battery demonstrates high specific capacity of 706.2 mA h g-1, and exceptional long-term charge/discharge stability exceeding 1250 cycles.