Nickel Foam Substrate Research Articles

Highly enhanced electrocatalytic OER with facile electrodeposition of MIL–53(Fe)/NiAl–LDH/NF and NiAl–LDH/MIL–53(Fe)/NF

This research investigates a new approach to improve the electrocatalytic rate of the Oxygen Evolution Reaction (OER), a key step in water electrolysis. The study focuses on two promising materials: MIL–53(Fe) and NiAl–LDH. MIL–53(Fe) offers several advantages: high catalytic activity, large surface area, and good chemical stability. NiAl–LDH is attractive due to its layered structure, tolerance to a wide range of pH levels, scalability, and cost-effectiveness. However, their limitations like low conductivity and restricted accessibility of active sites hinder their performance in water splitting applications. To address these limitations, novel composite thin films were created using a technique called layer–by–layer (LBL) electrophoretic deposition. These films, built on nickel foam (NF) substrates, included two configurations: MIL–53(Fe)/NiAl–LDH/NF and NiAl–LDH/MIL–53(Fe)/NF. The MIL-53(Fe)/NiAl-LDH/NF composite exhibited remarkable OER activity in alkaline electrolytes, requiring overpotentials of only 200, 270, and 370 mV to reach current densities of 20, 50, and 100 mA cm−2, respectively. The Tafel slope of 54.86 mVdec−1 suggests rapid reaction kinetics. Additionally, it demonstrated excellent long-term stability, lasting for at least 20 h. The success of the MIL–53(Fe)/NiAl–LDH/NF composite can be attributed to the LBL technique. This method creates a composite with a larger surface area, significantly improving OER efficiency. In contrast, the MIL–53(Fe)/NiAl–LDH/NF configuration had the opposite effect. The NF pores became blocked by the MIL–53(Fe) layer, reducing the overall surface area, hindering electron transfer, and thereby limiting oxygen production. The LBL deposition method used in this study proves its effectiveness in designing efficient electrocatalysts. This opens up possibilities for creating other multicomponent materials for energy applications. The findings provide valuable insights for future research on these promising composite materials, potentially leading to the development of cost-effective and high-performance catalysts for various electrochemical applications.

Supersaturated Doping-Induced Maximized Metal-Support Interaction for Highly Active and Durable Oxygen Evolution.

Metal-support interaction (MSI) is pivotal and ubiquitously used in the development of next-generation catalysts, offering a pathway to enhance both catalytic activity and stability. However, owing to the lattice mismatch and poor solubility, traditional catalysts often exhibit a metal-on-support heterogeneous structure with limited interfaces and interaction and, consequently, a compromised enhancement of properties. Herein, we report a universal and tunable method for supersaturated doping of transition-metal carbides via strongly nonequilibrium carbothermal shock synthesis, characterized by rapid heating and swift quenching. Our results enable ∼20 at. % Ni2FeCo doping in Mo2C, significantly surpassing the thermodynamic equilibrium limit of <3 at. %. The supersaturation ensures more catalytically active NiFeCo doping and sufficient interaction with Mo2C, resulting in the maximized MSI (Max-MSI) effect. The Max-MSI enables outstanding activity and particularly stability in alkaline oxygen evolution reaction, showing an overpotential of 284 mV at 100 mA cm-2 and stable for 700 h, while individual Ni2FeCo and Mo2C only last less than 70 and 10 h (completely dissolved), respectively. In particular, the SD-Mo2C catalyst also exhibits excellent durability at 100 mA cm-2 for up to 400 h in 7 M KOH. Such a significantly improved stability is attributed to the supersaturated doping that led to each Mo atom strongly binding with adjacent heteroatoms, thus elevating the dissolution potential and corrosion resistance of Mo2C at a high current density. Additionally, the highly dispersed NiFeCo also facilitates the formation of dense oxyhydroxide coating during reconstruction, further protecting the integrated catalysts for durable operation. Furthermore, the synthesis has been successfully scaled up to fabricate large (16 cm2) electrodes and is adaptable to nickel foam substrates, indicating promising industrial applications. Our strategy allows the general and versatile production of various highly doped transition-metal carbides, such as Ni2FeCo-doped TiC, NbC, and W2C, thus unlocking the potential of maximized or adjustable MSI for diverse catalytic applications.

Ce-doped NiCo-layered double hydroxide based self-supporting tremella-shaped nanoflower heterostructure as efficient electrocatalyst for the oxygen evolution reaction

NiCo-layered double hydroxide (NiCo-LDH) catalysts, which indicate a profound prospect of oxygen evolution reaction (OER) under alkaline conditions, are facing great challenges in terms of low electrical conductivity, restricted by poor conductivity, limited electrochemical reaction sites, and low-density of edge sites. The authors developed a simple and convenient in-situ one-pot self-assembly method. The Ce-doped defective NiCo-LDH hexagonal nanosheets and nitrogen-doped graphene fabricated the NiCoCe-LDH/RNF electrocatalyst on the nickel foam (NF) substrate, which demonstrated excellent OER activity under alkaline conditions, only needed 299 mV overvoltage to achieve 50 mA cm−2 current intensity, could last for 6 hours at 20 mA cm−2. The highly active OER benefited from the structural advantages of the novelty three-dimensional array structure. The novel geometric structure of tremella-shaped nanoflower integrated with curved nanosheets and curled edges loaded on NF provides more electrochemical reaction sites for intermediate coordination. The nitrogen-doped reduced graphene oxide accommodated better interaction between active materials and charge carriers, enhancing the conductivity and electron transfer performance of nanostructures. The effective synergistic between the heterostructures promoted the excellent OER electrocatalytic activity of NiFeCe-LDH/RNF nanocomposites. DFT calculations at the atomic level of pristine and Ce-doped NiCo-LDH exhibited that Ce-doping can reduce the Gibbs free energy of the potential-determining step and improve the catalytic activity of OER. This work has broadened the horizons for developing simple and highly available OER electrocatalysts.

Engineering intervention to disrupt the evolution of ZIF-67: Ultra-fast synthesis of arrayed Co(OH)2@ZIF-L in dozens of seconds for high-energy charge storage

Designing rational heterostructures of high-performance electroactive materials on conductive substrates with hierarchical structures is critical for advancing electrochemical energy storage technologies. In this study, a unique spatial structure is fabricated by vertically aligning two-dimensional (2D) structures of Co-ZIF-L on conductive nickel foam (NF) substrate through interruption of ZIF-67 formation. This is followed by an innovative electrochemical synthesis method that disrupts unstable surface coordination bonds in Co-ZIF-L, enabling the in-situ generation of Co(OH)2. The resulting Co(OH)2@ZIF-L/NF binder-free electrodes feature a hierarchical spatial structure and are synthesized in approximately 30 s. These electrodes showcase exceptional area capacity of 3.1 C cm−2 at 1 mA cm−2, attributed to their high specific surface area and layered architecture that promotes electrolyte penetration. Density Functional Theory (DFT) calculations reveal that the Co(OH)2@ZIF-L nanostructures have superior electrical conductivity compared to the individual components. Furthermore, a hybrid supercapacitor (HSC) based on Co(OH)2@ZIF-L/NF//AC exhibits an impressive energy density of 42 Wh kg−1 at a power density of 184.7 W kg−1. This research provides new insights into the efficient synthesis of high-performance electroactive materials with unique spatial structures and expands the potential applications of ZIF materials.

Phosphorus doping heterostructure La(OH)3@CuO @NF as an advanced electrocatalyst for the oxygen evolution reaction

Due to the prevailing energy shortages, the pursuit of new alternative energy sources is becoming increasingly urgent. Hydrogen production through water electrolysis has emerged as a crucial method. However, the sluggish four-electron reaction in the oxygen evolution reaction (OER) remains the primary rate-limiting step. In this study, we synthesized a heterostructure La(OH)3@CuO-P material on the nickel foam (NF) substrate. The experimental results demonstrate that after phosphating treatment, the heterostructure La(OH)3@CuO-P exhibits exceptional catalytic performance with only 215 mV overpotential, a Tafel slope value of 79.36 mV/dec, and a bilayer capacitance of 39.02 mF/cm2 at a current density of 10 mA/cm2 for OER in a 1 M KOH solution. These values are significantly superior compared to those obtained using heterostructure La(OH)3@CuO alone which showed an overpotential value of 365 mV at a current density of 10 mA/cm2. Moreover, during cyclic voltammetry testing for up to 500 cycles, La(OH)3@CuO-P also demonstrates relatively stable performance. Analyses suggest that composite heterostructure effectively addresses issues such as insufficient conductivity of La(OH)3 and monomer aggregation tendency for CuO while maintaining excellent properties for each component. By incorporating P atoms as dopants, the interaction between La, Cu, and P atoms not only facilitates fine-tuning of the electronic structure and optimization of the adsorption free energy (-OH), but also promotes an increase in catalytic active sites through sample size reduction, thereby further augmenting the performance of the OER.

Archipelago-like oxygen-vacancies-enriched amorphous-crystalline heterointerface for enhanced water splitting

Advancing the development of proficient bifunctional water splitting electrocatalysts and deciphering the underlying drivers of their performance are pivotal for accelerating the sustainable hydrogen energy sector. In this study, a novel Fe and P dual-doped cobalt molybdate electrocatalyst (P-FCMO@NF) is engineered in-situ on a nickel foam substrate that induces an archipelago-like amorphous-crystalline heterointerface as well as abundant oxygen vacancies (VO) on the near-surface, in favor of the electron transport and enhancing the water splitting capability respectively. Consequently, P-FCMO@NF exhibits excellent electrocatalytic performance in 1 M KOH solution. The water splitting device shows an ultra-low work voltage of merely 1.55 V at a current density of 10 mA cm−2 and demonstrates a long-term stability. The correlations between microstructural reconfiguration and sustainable electrocatalytic stability of P-FCMO@NF are deeply explored and verified. The work actually offers valuable insights that form a crucial foundation for the strategic design of innovative bifunctional electrocatalysts.

A hierarchical Cu2SnO4@NiCo-LDH nanofilament structure as a new-potent electrode for energy storage

Our research continues to explore innovative, efficient electrode materials and new production processes for electrochemical devices. Supercapacitors remain at the forefront of energy storage solutions, thanks to their exceptional power density, cycling durability, and mechanical robustness. For the first time, we have developed a hierarchical Cu2SnO4@NiCo-LDH nanocomposite using a straightforward hydrothermal technique coupled with an annealing process on a nickel foam substrate. This study introduces the novel Cu2SnO4@NiCo-LDH (CSO@NC-LDH) material, distinguished by its unique nanofilament structure and impressive electrochemical properties, including a high specific capacitance of 2791.5 F g−1 at 1 A g−1. Additionally, we created an asymmetric supercapacitor using CSO@NC-LDH for the positive electrode and activated carbon (AC) for the negative electrode. This system showcases an outstanding energy density of 108.67 Wh kg−1 and a notable power density of 1.05 kW kg−1 at an operating voltage of 1.6 V. These exciting results highlight the promising potential of CSO@NC-LDH nanofilaments as advanced electrodes for next-generation energy storage devices.

Microwave-assisted hydrothermal synthesis of αβ-Ni(OH)2 nanoflowers on nickel foam for ultra-stable electrodes of supercapacitors

Transition metal hydroxides (TMHs) are considered promising materials for supercapacitors because of their high theoretical capacitance and tunable morphology. Among TMHs, nickel hydroxide stands out for its multiple oxidation states, facilitating charge storage. This paper reports on a novel microwave-assisted hydrothermal technique employed to synthesize mixed-phase nickel hydroxide nanoflowers directly at the surface of nickel foam substrates with improved electrochemical stability compared to pure phases of nickel hydroxide. The analysis of nickel hydroxide in different phases alpha, beta and mixed-phase materials using physiochemical techniques like XRD, SEM, EDX, RAMAN, FT-IR and TGA is explained. The areal capacitance calculated from GCD tests for α-Ni(OH)2, β-Ni(OH)2 and αβ-Ni(OH)2 is estimated 7.35 F/cm2, 2.66 F/cm2 and 5.12 F/cm2 at a current density of 10 mAcm−2. The mass-specific capacitance calculated from GCD tests for α-Ni(OH)2, β-Ni(OH)2 and αβ-Ni(OH)2 is estimated 2311 Fg−1, 688 Fg−1 and 1511 Fg−1 at a current density of 10 mAcm−2. The cyclic stability test revealed the superior cycling performance of nickel hydroxide in mixed-phase as the cathode of an ultralong supercapacitor with nearly 100% capacitance retention after 5000 cycles at 50 mAcm−2. The proposed synthesis technique advances the efficiency and control of nanostructure geometry, providing insights into the design for electrodes of extreme-performance supercapacitors. However, conventional synthesis methods are time-consuming and energy-intensive. These findings underscore the potential of mixed-phase nickel hydroxide as an outstanding electrode material with extended cyclic performance for supercapacitors, contributing to the improvement of energy storage technologies in the renewable energy landscape.

ZnO/NiFe2O4 heterostructure on nickel foam for the electrochemical detection of uric acid

In this study, heterostructures containing hydrothermally derived ZnO and combustion derived NiFe2O4 were co-deposited on nickel foam (NF) substrate. The modification of NF based substrate with the synthesised electrocatalysts is capable of increasing the electrochemically active surface area (ECSA) due to its porous network. The fabricated ZnO@NF, NiFe2O4@NF and ZnO/NiFe2O4@NF electrodes were tested in phosphate buffer saline (PBS) (pH = 7.4 ± 0.2) to understand their chemical kinetics which reveals a diffusion-controlled process. A comparative study reveals that the presence of surface charges on ZnO/NiFe2O4@NF electrode, influences the selectivity by enhancing the sensitivity towards UA which is attributed to the low charge transfer resistance and its higher ECSA of 1.487 cm2. The linear response current was observed between 0.52 mM and 1.48 mM with a detection limit (LOD) of 8.22 μM and limit of quantification (LOQ) of 27.4 μM. The sensitivity was found to be 2.31 mA.mM−1cm−2. The main advantages of ZnO/NiFe2O4@NF electrode is its simple fabrication technique which is inexpensive, stability over a period of 13 days with current loss of ∼19.2 %. The proposed ZnO/NiFe2O4 based non-enzymatic UA sensor is capable of selectively detecting UA in the presence of various interferents. UA acts as a biomarker for the diagnosis of different stages of chronic kidney disease (CKD). Hence, the validity of the developed heterostructure was investigated for real time UA sensing using spot urine samples. The recovery percentage was found to be between 95.7 % and 103.5 % further paving way for the use of this electrode for diagnosis of CKD.

Nickel sulfide nanorods encapsulated in Nitrogen-Doped carbon on nickel foam in situ derived from Saccharomycetes cerevisiae for the selective oxidation of biomass

The design and development of an efficient catalyst for the electrocatalytic oxidation reaction of 5-hydroxymethylfurfural (HMF) require a novel, cost-effective, environmentally friendly, and safe preparation method. In this study, we synthesized nickel sulfide nanorods encapsulated by nitrogen-doped carbon on a nickel foam substrate (Ni3S2@NC/NF), derived in situ from Saccharomyces cerevisiae. The utilization of a gas-phase route facilitated the binding of C, N and S elements to the NF substrate. The resulting Ni3S2@NC/NF catalyst exhibited excellent electrocatalytic performance in the HMF oxidation reaction (HMFOR), achieving a complete conversion of HMF, a selectivity of 95.6 % for 2,5-furandicarboxylic acid, and a Faraday efficiency of 88.9 % at a potential of 1.45 V. Moreover, in situ electrochemical impedance spectroscopy revealed an enhanced charge transfer rate for the Ni3S2@NC/NF catalyst during the interfacial HMFOR. Additionally, the catalyst demonstrated outstanding stability after five cycles of electrolysis. Therefore, this work provides a valuable guide for using microorganisms as sources of C, N, and S in the targeted synthesis of metallic electrocatalysts.

Hierarchical graphene oxide/nano-pyramidal stainless-steel on nickel foam substrate: A flexible electrochemical sensor for arsenic compound detection

The organoarsenic compound roxarsone (ROX) is added to chicken feed to enhance nutritional value. Although organic arsenic is generally less harmful than inorganic arsenic, concerns have arisen about its potential to transform into inorganic forms when excreted in animal waste, raising environmental and human health concerns. The potential dangers of long-term ROX exposure require reliable methods for the detection of the target analyte. In the current study, fabricated nanoscale graphene oxide (GO)/stainless steel (SS) pyramidal structures on nickel foam (NF) is used as an electrode in the electrochemical detection of ROX. The proposed sensor was shown to outperform existing devices in terms of electrochemical activity, resulting in a wider linear range of detection for ROX (0.05–83.15 µM) and lower detection limit (LOD) (0.006 µM). Further, real sample analysis on water and meat samples confirmed the feasibility of the proposed GO/SS/NF sensor for the real-time detection of ROX in real-world applications. This research provides evidence to support the development of heterojunctions to improve ion transport channels and surface-active sites to promote ion mobility to enhance electrochemical responses.

Efficient generation of singlet oxygen (1O2) by CoP/Ni2P@NF for degradation of sulfamerazine through a heterogeneous electro-Fenton process at circumneutral pH

In electro-Fenton (EF), the development of a catalytic material with wide pH application range and high interference resistance is more suitable for practical wastewater treatment. In this study, the nanoneedle-shaped CoP/Ni2P heterostructure loaded onto a nickel foam substrate (CoP/Ni2P@NF) was successfully fabricated, which was used as a cathode material for heterogeneous electro-Fenton (Hetero-EF) to degrade sulfamerazine (SMR) at circumneutral pH. The SMR degradation efficiency within 90 min went to 100% and 87% at initial pH of 6.8 and 11, respectively. Experiments and theoretical calculations demonstrated that the heterostructure of CoP/Ni2P redistributed the interfacial charge and accelerated the electron transfer, resulting in different two-electron oxygen reduction (2e−ORR) selectivity and activity than CoP and Ni2P. The ion interference and complex water quality experiment exhibited that the degradation performance remained almost unchanged, showing better anti-interference ability and complex water quality applications. Through quenching experiments and EPR tests, it is confirmed that singlet oxygen (1O2) was the major reactive oxygen species (ROS) and 1O2 was converted from hydroxyl radical (·OH) adsorbed on the catalyst surface. This study provides an efficient catalyst for the application of Hetero-EF to remove organic compounds in complex water at circumneutral pH.

Integration of vanadium diphosphide with 2D cobalt phosphide architected as an extensible redox active positrode for alkaline supercapacitor

Metal phosphides in the form of rationally constructed two-dimensional (2D) nanosheets hold significant promise as versatile materials for energy storage applications. This study introduces a novel hybrid supercapacitor electrode, composed of a binder-free vanadium phosphide integrated cobalt phosphide (VP@CP) on a nickel foam substrate. The fabrication process involves the hydrothermal growth of Co2(OH)2BDC (BDC- 1,4-benzenedicarboxylate) nanosheets on a Ni-foam substrate (CMF-Ni), followed by the deposition of VO2 on CMF nanosheets (VO@CMF-Ni) using chronoamperometry and phosphorization of the VO@CMF-Ni to yield VP@CP-Ni nanosheets. Particularly, the density functional theory (DFT) results show that the VP2 integrated Co2P sample provides metallic behavior and low adsorption energy of OH− ions, resulting in improved electrochemical redox process. These bimetallic phosphides exhibit outstanding properties, including enhanced pathways for rapid ion transport and storage, increased electronic conductivity, and expanded electroactive regions facilitating the faradaic charge storage process. Due to the presence of vanadium and cobalt coupled sites, the fabricated VP@CP-Ni electrode was able to attain a maximum areal capacity (CAR) of 971 mA h cm−2 at 6 mA cm−2. Additionally, the fabricated hybrid device (HDC) exhibits an impressive specific energy (SE) of 30.9 Wh kg−1 at a specific power (SP) of 1344 W kg−1, and excellent cyclic durability. These remarkable results stimulate the exploration of such possible 2D VP@CP-Ni nanosheets with promising charge storage electrode capabilities to develop a future era of energy storage devices.

Boosting hydrogen production via alkaline water splitting: Impact of Ag doping in Gd2O3 nanosheet arrays

Hydrogen is a preferable renewable energy carrier in decarbonization efforts to develop sustainable and carbon-free economies due to its high energy density and absence of pollutant emissions during combustion. Among others, electrochemical water splitting (EWS) is a sustainable and eco-friendly technology for producing green hydrogen, representing an essential initial step towards achieving carbon neutrality. In this study, we synthesized a bifunctional electrocatalyst by vertically anchoring Ag-doped Gd2O3 nanosheet arrays onto a three-dimensional nickel foam (NF) substrate. The developed materials were thoroughly investigated using various analytical techniques. Furthermore, the electrocatalyst effectively performed oxygen evolution reactions (OER) and hydrogen evolution reactions (HER). The Ag4%-Gd2O3/NF exhibited boosted HER activity, achieving higher current densities ranging from 10 to 400 mA cm−2 at an overpotential between 14 and 122 mV. This study also highlights the considerable impact of metal sites in both Ag4%-Gd2O3/NF and Gd2O3/NF on the HER catalytic process. Similarly, the Ag4%-Gd2O3 electrocatalyst exhibited superior OER activity, with an overpotential of 209 mV at 10 mA cm−2. The optimized composition also shows Tafel slope of 25 and 20 mVdec−1. Furthermore, Ag4%-Gd2O3 demonstrated the ability to generate oxygen gas bubbles in approximately 20 h for OER, making it an attractive material for energy conversion and storage devices.

Probing the performance of Co-precipitated Co3(PO4)2@W3(PO4)4/GO electrodes for supercapacitor application

A critical first step in realizing high-performance supercapacitors is the growth of functional electrodes that are inexpensive, stable, and extremely active. To create a variety of electrodes, we present here an inventive approach to fabricating an ordered microporous Co3(PO4)2@W3(PO4)4/GO composites electrode on a nickel foam (NF) substrate that was first created via co-precipitation techniques for nanoparticles and then drop casting method for fabrication of these electrodes. The Co3(PO4)2@W3(PO4)4/GO composite electrodes show good electrochemical activity in three electrode configurations, thanks to its abundant active sites, and high specific surface area provided by graphene oxide (GO) structured microporous structure that facilitates the charge/mass transfer processes. Additionally, Co3(PO4)2@W3(PO4)4/GO composite electrodes are rightly employed as binder-free electrodes for supercapacitor applications, providing excellent specific capacitances, energy and power densities as well as good electrochemical firmness. The Co3(PO4)2@W3(PO4)4/GO electrode exhibits excellent performance, delivering a high specific capacitance of 1230 F/g from cyclic voltammetry (CV), 1420 F/g from galvanostatic charge-discharge (GCD) and long-term cycling stability of over 74.7 % after 10, 000 complete cycles.

Incorporation of Ag in Co9S8-Ni3S2 for Predominantly Enhanced Electrocatalytic Activities for Oxygen Evolution Reaction: A Combined Experimental and DFT Study.

Electrodeposition of abundant metals to fabricate efficient and durable electrodes indicate a viable role in advancing renewable electrochemical energy tools. Herein, we deposit Co9S8-Ag-Ni3S2@NF on nickel foam (NF) to produce Co9S8-Ag-Ni3S2@NF as a exceedingly proficient electrode for oxygen evolution reaction (OER). The electrochemical investigation verifies that the Co9S8-Ag-Ni3S2@NF electrode reveals better electrocatalytic activity to OER because of its nanoflowers' open-pore morphology, reduced overpotential (η10=125 mV), smaller charge transfer resistance, long-term stability, and a synergistic effect between various components, which allows the reactants to be more easily absorbed and subsequently converted into gaseous products during the water electrolysis route. Density functional theory (DFT) calculation as well reveals the introduction of Ag (222) surface into the Co9S8 (440)-Ni3S2 (120) structure increases the electronic density of states (DOS) per unit cell of a system and increases the electrocatalytic activity of OER by considerably lowering the energy barriers of its intermediates. This study provides the innovation of employing trimetallic nanomaterials immobilized on a conductive, continuous porous three-dimensional network formed on a nickel foam (NF) substrate as a highly proficient catalyst for OER.

Co‐W (Hydr)oxide with Ultralow Ru Promotes Water Dissociation Coupled H+ Abstraction in Alkaline HER

The hydrogen evolution reaction in alkaline water electrolysis is facilitated through the electrodeposition of trimetallic catalyst on nickel foam using the chronoamperometry technique. Specifically, the trimetallic catalyst CoWRu@NF is deposited onto a nickel foam substrate. The catalytic performance of this trimetallic catalytic electrode for the Hydrogen Evolution Reaction (HER) is then assessed in a 1.0 M potassium hydroxide (KOH) solution. This specially designed trimetallic catalytic electrode system efficiently provides the more active sites through the Co component. Subsequently, it facilitates the reduction of protons (H+) to generate hydrogen gas using the Ru component. Tungsten acts as a co‐catalyst in the system for water dissociation promotor by removing hydroxide formed after water dissociation and preventing the deactivation of Ruthenium by certain reaction intermediates. The CoWRu@NF trimetallic catalyst demonstrates excellent activity, showcasing a low overpotential (‐8 mV) to achieve a current density of ‐10 mA/cm2. Additionally, it exhibits low Tafel slope values (101.2 mV dec‐1), credited to the presence of cobalt and tungsten alongside Ruthenium in the catalytic system. This configuration is specifically designed to enhance the kinetics of the hydrogen‐evolving reaction.

Boosting Oxygen Electrocatalysis via Pre-Magnetized Multi Metallic Electrocatalyst

The quest for highly efficient durable and cost-effective electro catalysts for oxygen evolution reaction (OER) remains a pivotal focus in the advancement of renewable energy conversion technologies. Transition metal-based alkaline media electrocatalysts have emerged as promising candidates due to their versatile electronic structures and cost effectiveness. Among these, magneto-electrocatalysts, integrating magnetic properties with electrocatalytic functionalities, represent a novel frontier in OER research. In this study, we introduce a novel approach to enhance OER performance via the utilization of pre-magnetized multi-metallic (Fe-Ni-Co ) doped electrocatalysts, harnessing electron spin polarization. We tailored the electronic structure and magnetic properties of the catalyst, promoting and validating the principle of spin polarization for augmenting OER activity. Through a comprehensive experimental study, we have investigated how the inclusion of magnetic components influences the catalytic activity, stability, and overall efficiency of the electrocatalyst during OER. Experimental methodologies involving material synthesis, characterization techniques (XRD,FE-SEM, VSM study) and electrochemical analysis are employed to assess the structural, magnetic, and electrocatalytic properties of the synthesized pre-magnetised electrocatalyst.We employed the Fe-modified Nickel foam (NF) substrate as a catalyst support. Three distinct electrocatalysts (EC) [NF/Fe-Ni, NF/Fe-Co, and NF/Fe-NiCo] were electrodeposited in two different types: (electrodeposition without magnetic field) and (electrodeposition with applied magnetic field 0.6 T). Observations revealed that for all three electrocatalyst, the electrocatalysts [which were synthesized by applying a magenetic field during eletro deposition and later on OER activity was measured in the absence of magnetic field ] exhibit superior electrocatalytic activity towards OER compared to its counterparts . The highest electrocatalytic activity is provided by NF/Fe-NiCo of 0.5 mA/cm2 ECSA in the absence of a magnetic field and 0.533 mA/ cm2 ECSA in the presence of magnetic field. This is superior to that of the precious metal Ru, which has a specific activity of 0.49 mA/ cm2 ECSA at 1.5V (versus RHE). After analysing the OER performance of the catalyst, we found that the activity of NF/Fe-NiCo improved from 69.15 to 89.55 mA/ cm2 when a magnetic field was applied. Capacitance measurements (15.16% increase) and ECSA measurements (22.1% increase) also corroborated this. The overpotential measurement decreased from 243.03 mV to 239.1 mV at 100 mA/ cm2. As a result, for both sets of catalysts, the magnetic field improved the current density. Comparatively OER performance in absence of magnetic field of the electrocatalyst which was synthesized by electrodeposition with applied magnetic field was better than (for the second catalyst OER activity studied under applied magnetic field. This suggests that rather than applying a magnetic field during long-term electrolysis, one may opt to apply a magnetic field during electrocatalyst production. When we compared the OER performance of these two, we discovered that NF/Fe-NiCo exhibits the greatest activity of all catalysts at 1.5V, with 91.3 mA/ cm2, although the percentage rise is lower than that of the other catalysts. However, compared to the rise in activity, the ECSA data reveals a significant increment of 56%. The data on capacitance and overpotential likewise correspond with the current density trend. With the lowest overpotential of 236.35 mV when measured at 100 mA/cm2, the NF/NiCo catalyst performed the best overall among all the catalysts. Our findings underscore the significance of electron spin polarization in boosting electrocatalytic performance, offering a promising avenue for the design and development of advanced catalysts for sustainable energy applications and in the context of their commercial viability and integration into industrial-scale electrochemical devices.

Facile hydrothermal synthesis of ZnIn2S4/TiO2 nanosheets for promoted hydrogen evolution reaction

The current study was conducted by introducing a narrow bandgap semiconductor, ZnIn2S4, with the goal of addressing the inefficiency of hydrolysis dissociation and the limited visible light absorption capacity faced by TiO2 as a hydrogen evolution reaction (HER) catalyst due to its low conduction band position and wide bandgap. Using a one-step hydrothermal process, ZnIn2S4 nanosheet/TiO2 nanorod heterostructures were built on nickel foam substrates. The nanosheet structure of ZnIn2S4 is shaped like a flower, which greatly increased the roughness of the TiO2 surface and revealed additional active sites. The ZnIn2S4/TiO2 heterostructure demonstrates quick reaction kinetics and effective electron transport capability, as demonstrated by the electrochemical test results. An overpotential of just 195 mV is required to obtain a current density of 10 mA cm−2. In addition, the overpotential is further decreased to 160 mV under simulated solar radiation. Furthermore, ZnIn2S4 addition minimizes the free energy of hydrogen adsorption on the TiO2 surface and optimizes the position of its Fermi energy level, improving the usage of photogenerated carriers, according to density functional theory (DFT) calculations. This work validates the prospective use of ZnIn2S4/TiO2 heterostructures in photoelectrocatalysis and offers a fresh viewpoint for developing high-performance HER catalysts.

Synergistic enhancement of bifunctional activity and stability of seawater electrolysis by in situ etching and concentration strategies

An effective way to lessen the scarcity of freshwater resources is recognized as seawater electrolysis. Significant importance is attached to developing bifunctional catalysts appropriate for seawater electrolysis in industrial settings. In situ, etching and electrodeposition on nickel foam substrates were used in this study to create SNiFe@NF catalysts. Experiments demonstrated a positive link between catalytic activity and the KOH concentration in the electrolyte. The addition of sulfur not only increases catalytic activity but also increases resistance to Cl-. This is because sulfur has a low electronegativity, which helps to produce hydroxyl oxides by modulating the electronic structure between Ni and Fe. As predicted, at a current density of 100 mA cm−2, the SNiFe@NF catalyst demonstrated extraordinarily low overpotentials of 90 mV (HER) and 261 mV (OER). Moreover, after undergoing stability tests, the catalyst surface developed a SO42- layer that created a Cl- barrier, providing the basis for excellent stability. Interestingly, the electrolyzer used using SNiFe@NF catalysts also showed an outstanding 1.48 V at 100 mA cm−2 overall water splitting capacity. Furthermore, after 20 hours of continuous operation, no attenuation was seen in the catalysts' performance under high-temperature and high-alkalinity industrial settings. The results of this work provide a simple and efficient method for producing highly active bifunctional corrosion-resistant catalysts, which have significant ramifications for the development of the hydrogen economy.