Hydrogen Evolution Performance Research Articles

Fabrication of 0D/2D amorphous NixB/ZnIn2S4 S-scheme for enhanced photocatalytic hydrogen evolution performance

The design and synthesis of low-cost hydrogen evolution photocatalysts with high carrier separation capability and visible light responsiveness are key factors in increasing hydrogen production. In this work, zero-dimensional (0D) amorphous nickel boride (NixB) was synthesized using a reduction method. Subsequently, a 0D/2D amorphous NixB/ZnIn2S4 S-scheme heterojunction was fabricated through electrostatic attraction. This heterojunction exhibited stronger visible light responsiveness and enhanced photogenerated carrier separation performance. The morphology, composition, elemental, structural, and light absorption capacities of the as-synthesized composites were researched by SEM, TEM, XRD, XPS, and UV–vis DRS. The ability to separate photogenerated carriers were evaluated through photoelectrochemical experiments. The hydrogen evolution rate of NixB/ZnIn2S4 (2208 μmol h−1 g−1) increased 25 times than that of single ZnIn2S4 in sacrificial solution, and the apparent quantum yield (AQY) at 400 nm was 14.25 %. This study gives evidence of the great preponderance of S-scheme heterojunction and multidimensional material co-construction in improving hydrogen precipitation.

2D Porphyrin-Based Covalent-Organic Framework/PEG Composites: A Rational Strategy for Photocatalytic Hydrogen Evolution.

Two-dimensional porphyrin-based covalent-organic frameworks (2D-por-COFs) have gained significant attention as attractive platforms for efficient solar light conversion into hydrogen production. Herein, it is found that introducing transition metal zinc and polyethylene glycol (PEG) into 2D-por-COFs can effectively improve the photocatalytic hydrogen evolution performance. The photocatalytic hydrogen evolution rate of ZnPor-COF is 2.82 times higher than that of H2Por-COF. Moreover, ZnPor-COF@PEG has the highest photocatalytic hydrogen evolution efficiency, which is 1.31 and 3.7 times that of pristine ZnPor-COF and H2Por-COF, respectively. The filling of PEG makes the layered structure of COFs more stable. PEG reduces the distortion and deformation of the carbon skeleton after the experiment of photocatalytic hydrogen evolution. The layered stacking and crystallization of 2D-por-COFs are also enhanced. Meanwhile, the presence of PEG also accelerates the transfer of excited electrons and enhances the photocatalytic hydrogen evolution activity. This strategy will provide valuable insights into the design of 2D-por-COFs as efficient solid photocatalysts for solar-driven hydrogen production.

0D/2D heterojunction constructed by Ag2S quantum dots anchored on graphdiyne (g-CnH2n−2) nanosheets for wide spectrum photocatalytic H2 evolution

Precisely crafting heterojunctions for efficient charge separation is a major obstacle in the realm of photocatalytic hydrogen evolution. A 0D/2D heterojunction was successfully fabricated by anchoring Ag2S quantum dots (Ag2S QDs) onto graphdiyne (GDY) nanosheets (Ag2S QDs/GDY) using a straightforward physical mixing technique. This unique structure allows for excellent contact between GDY and Ag2S QDs, thereby enhancing the rate of charge transfer. The light absorption capabilities of Ag2S QDs/GDY extend up to 1200 nm, enabling strong absorption of light, including infrared. Through DFT calculations and in-situ XPS analysis, it was demonstrated that incorporating Ag2S QDs onto GDY effectively modulates the electronic structure, promotes an internal electric field, and facilitates directional electron transfer. This directed electron transfer enhances the utilization of electrons by GDY and Ag2S QDs, with the added benefit of Ag2S QDs serving as electron reservoirs for efficient photocatalytic hydrogen evolution. A 7 %Ag2S QDs/GDY composite exhibited impressive efficiency and stable performance in photocatalytic hydrogen evolution (2418 μmol g−1 h−1), which is much higher than that of GDY and Ag2S QDs. This study conclusively demonstrates that the 0D/2D heterojunction formed by GDY and Ag2S QDs can establish high-quality contact and efficient charge transfer, ultimately enhancing photocatalytic performance.

Fabrication of S‐Scheme GDY‐CuI/ZnWO4 Photocatalyst to Promote Electron Transfer for Enhanced Photocatalytic H2 Evolution

AbstractThe exceptional performance of graphdiyne (GDY) in photocatalysis for hydrogen evolution attracts much attention, but the narrow band gap of GDY complicates the effective realization of the dissociation between photogenerated charges and photogenerated holes. In this study, GDY‐CuI is synthesized by cross‐coupling method, and the wide bandgap ZnWO4 is introduced into it by low‐temperature mixing, which effectively constructed the GDY‐CuI/ZW‐50 double S‐scheme heterojunction. The optimized GDY‐CuI/ZW‐50 catalyst photocatalytic hydrogen evolution performance reached 308.61 µmol after 5 h of visible light irradiation, which is 12.86 and 6.56 times than that of GDY‐CuI and ZnWO4, respectively. The improved efficiency of hydrogen evolution is attributed to the formation of a double S‐scheme heterojunction between GDY, CuI, and ZnWO4 and an internal electric field, which promotes charge transfer, reduces the complexation rate of photogenerated electrons, and enhances the redox capacity of photogenerated charges. A combination of photoelectrochemical analysis, in situ X‐ray photoelectron spectroscopy (In situ XPS), ultraviolet photoelectron spectroscopy (UPS), and density functional theory (DFT) results revealed the electron transfer mechanism. This work will provide new ideas for the design and preparation of GDY‐based photocatalysts.

Covalently Linking Reduced Graphene Oxide Facilitated Electrodeposition of MoS2 on Silicon Pyramidal Photocathode To Enhance Hydrogen Evolution.

In recent years, increasing attention has been paid to photoelectrochemical (PEC) hydrogen production owing to the utilization of sustainable solar energy and its promising performance. Silicon-based composites are generally considered ideal materials for PEC hydrogen production. However, slow reaction kinetics and poor stability are still key factors hindering the development of silicon-based photoelectrocatalysts. Herein, we present an n+-p Si pyramidal photocathode assembly method to load reduced graphene oxide (rGO) onto the surface of the n+-p Si pyramid by covalently linking (Si/rGO). rGO is utilized as a conductive layer to reduce the interfacial charge-transfer resistance. Then, MoS2 can be successfully electrodeposited on the surface of Si/rGO to form the Si/rGO/MoS2 composite, which possesses excellent PEC hydrogen evolution performance with a high and stable photocurrent of -41.6 mA cm-2 and a hydrogen evolution rate of about 18.1 μmol min-1 cm-2 under 0 V (vs RHE). The covalently linking rGO layer effectively enhances the transfer of photogenerated carriers between the Si substrate and MoS2. MoS2 provides abundant hydrogen evolution active sites, which accelerate the surface reaction kinetics, as well as a protective layer for the Si pyramidal array structure. This work provides a low-cost, convenient, and efficient way of preparing silicon-based photocathodes.

Enhanced photocatalytic hydrogen generation efficiency through molybdenum-sulfur dual sites synergistic catalysis

Photocatalysis has gained significant attention in recent years for water splitting, with graphitic carbon nitride (g-C3N4) emerging as a promising candidate. However, the low carrier mobility and the lack of active sites for hydrogen evolution limit photocatalytic hydrogen evolution performance. Herein, this work presents a facile approach to achieve single Mo sites with a unique local coordination structure featuring one Mo atom coordinated with two nitrogen atoms and one sulfur atom. Among the prepared photocatalysts, 6 wt% Mo/SCN exhibits the highest photocatalytic hydrogen evolution activity with a yield rate of 4.05 mmol g-1 h-1, which is 13 times higher than that of pure g-C3N4 and superior to most of the g-C3N4 series photocatalysts. Experimental results and density functional theory calculations confirm that the Mo single-atom and S atom have synergistic catalysis under the co-modification, and the formed Mo-S bonds will enhance the ability of the substrate to anchor the Mo single-atom to enhance the stability of the photocatalyst. This work offers insights into transition metal single-atom and synergistic catalysis design for photocatalytic hydrogen evolution.

Enhanced photocatalytic hydrogen evolution performance of Pd/g-C3N4 with carbon vacancies

Exploration of highly active, stable and environmentally friendly photocatalytic materials is key to address the problem for hydrogen production by photocatalytic water splitting. Among all the photocatalysts, graphitic carbon nitride (g-C3N4) has gained attention for its stable graphite-like electronic structure, appropriate band gap (∼2.7 eV), and high stability. However, the limited visible light absorption capacity and fast recombination of electron-hole pairs severely limit the photocatalytic performance of g-C3N4. In this study, Pd/g-C3N4 Schottky heterojunctions with carbon vacancies were prepared by an impregnation method. The surface plasmon resonance (SPR) effect of Pd0 nanoparticles and the incorporation of carbon vacancies synergistically reduce the band gap of g-C3N4, expanding its light response absorption capacity and increasing surface active sites, as a result of these modifications, the separation of electron-hole pairs is effectively improved, and photocatalytic water splitting for hydrogen production is greatly enhanced. Photocatalytic performance of Pd/g-C3N4 photocatalysts demonstrate outstanding hydrogen evolution efficiency under solar light irradiation. A convincing mechanism for the enhanced photocatalytic performance of the Pd/g-C3N4 Schottky heterojunctions was suggested. This investigation emphasizes a straightforward and efficient approach for fabricating of based g-C3N4 composite materials with exceptional photocatalytic efficiency.

Efficient Visible Light Photocatalytic Hydrogen Evolution by Boosting the Interfacial Electron Transfer in Mesoporous Mott-Schottky Heterojunctions of Co2P-Modified CdIn2S4 Nanocrystals.

Photocatalytic water splitting for hydrogen generation is an appealing means of sustainable solar energy storage. In the past few years, mesoporous semiconductors have been at the forefront of investigations in low-cost chemical fuel production and energy conversion technologies. Mesoporosity combined with the tunable electronic properties of semiconducting nanocrystals offers the desired large accessible surface and electronic connectivity throughout the framework, thus enhancing photocatalytic activity. In this work, we present the construction of rationally designed 3D mesoporous networks of Co2P-modified CdIn2S4 nanoscale crystals (ca. 5-6 nm in size) through an effective soft-templating synthetic route and demonstrate their impressive performance for visible-light-irradiated catalytic hydrogen production. Spectroscopic characterizations combined with electrochemical studies unravel the multipathway electron transfer dynamics across the interface of Co2P/CdIn2S4 Mott-Schottky nanoheterojunctions and shed light on their impact on the photocatalytic hydrogen evolution chemistry. The strong Mott-Schottky interaction occurring at the heterointerface can regulate the charge transport toward greatly improved hydrogen evolution performance. The hybrid catalyst with 10 wt % Co2P content unveils a H2 evolution rate of 20.9 mmol gcat -1 h-1 under visible light irradiation with an apparent quantum efficiency (AQE) up to 56.1% at 420 nm, which is among the highest reported activities. The understanding of interfacial charge-transfer mechanism could provide valuable insights into the rational development of highly efficient catalysts for clean energy applications.

Effective anaerobic digestion performance from kitchen wastewater by nanoscale zero-valent iron composite materials: Hydrogen corrosion capability and biological biogas upgrading

In this study, nanoscale zero-valent iron (nZVI) was modified by carboxymethylcellulose (CMC), extracellular polymeric substances (EPS) and sodium dodecyl sulfate (SDS), which were compared for the ability of hydrogen corrosion and then for the biogas upgrading during kitchen wastewater anaerobic digestion. The results showed that three nZVI composite materials addition could increase hydrogen evolution performance by 6.11∼10.30 % compared with nZVI. Especially, the hydrogen evolution from sodium dodecyl sulfate modified composite material reached 121.0 mL/g. The continuous release of hydrogen promoted the biogas yield to 510.96 mL/gVS in reaction group with SDS12-nZVI10 addition (N4), with CH4 content reached 93.37 %. Microbial community analysis showed that the total relative abundance of Methanothrix and Methanolinea was 43.60 % in N4, which was higher than other groups. It was indicated that H2-assisted biogas upgrading with nZVI composite materials addition was achievable, particularly in N4.

Development of Transition Metal Phosphates NiCoP/NF and Evaluation of Their Hydrogen Evolution Properties

Energy and the environment are one of the most important global issues in the 21st century. In order to avoid the excessive destruction of the environment and human settlements by fossil fuels, and achieve sustainable development of the Earth, clean energy carrier hydrogen shows its application value. Facing the challenges in preparing transition metal phosphides, in this study, transition metal salts and urea were used as raw materials to react under hydrothermal conditions. The transition metal basic carbonate NiCo2(CO3)1.5OH3 was grown in situ on nickel-foam (NF) substrates. After low-temperature phosphating treatment, NiCoP alloy phosphide electrocatalysts (NiCoP/NF) grown on nickel-foam substrates were obtained. The electrochemical hydrogen evolution performance was tested in 1 mol/L KOH alkaline electrolyte solution. Experiments show, NiCoP/NF heterostructure catalyst has excellent hydrogen evolution performance. In an alkaline medium, the overpotential required to obtain the catalytic current density of 10 mA/cm2 is only 93 mV, and the Tafel slope is 118 mV/dec. This is largely due to: 1) the good dispersion of NiCoP/NF nano-catalyst on the Nickel Foam substrate increased the number of active sites exposed; 2) the heterostructure promotes the electron interaction between NiCoP and NF; 3) theoretical calculations show that the construction of NiCoP/NF heterostructure can effectively reduce the dissociation barrier of water, promote the dissociation of water, the kinetic reaction process of electrocatalytic hydrogen evolution is accelerated. Therefore, the construction of NiCoP/NF nanostructured heterogeneous catalysts enriches the application of non-noble metal nanomaterials in the field of hydrogen production from water electrolysis.

Surface cyano groups optimize the charge transfer of poly heptazine imide for enhanced photocatalytic H2 evolution

Surface functionalization has been considered as an effective strategy to manipulate charge separation of carbon nitride and therefore to largely improve the photocatalytic H2 evolution efficiency. Poly heptazine imide (PHI) is a new class of crystalline carbon nitride frameworks that exhibits remarkable photocatalytic performance for hydrogen evolution. To further improve the H2 evolution performance of PHI and explore the reaction mechanism, ammonium thiocyanate was used as a precursor for the synthesis of poly heptazine imide at elevated temperatures under molten salt conditions. The optimized PHI with an abundance of surface cyano groups shows a significantly enhanced photocatalytic performance for H2 evolution, which is 4.3 times that on pristine PCN. Most importantly, the surface cyano group adjusts the electron intensity of the polymeric framework, enhances the light absorbance, reduces the bandgap, and improves the charge separation efficiency. The synthetic technique also could be applied to other sulfur-containing precursors for the synthesis of PHI frameworks with excellent hydrogen evolution production performance.

Preferential heteroatom substitution into ZnIn2S4 nanosheets boosts photocatalytic hydrogen production

Interior modification through preferential substitution of heteroatoms in 2D materials can rescue surface reactive sites for enhanced charge kinetics and photo-activity. Here, Ru and Ni heteroatoms were successfully incorporated in ZnIn2S4 (ZIS) nanosheets via a simple hydrothermal technique. Ru-ZIS photocatalysts exhibited improved photo–water splitting activity (26,400 µmol. h−1g−1) and good stability than that of Ni-ZIS and pristine ZIS under simulated sunlight, which may be related to the increase in reactive sites with Ru substitution, optimized adsorption-free energy of the reaction intermediates and charge kinetics. Ru substitution influenced Zn site availability and thus coordinated bonding with surrounding S ions. Ru-ZIS showed excellent hydrogen evolution performance and minimal change in Gibbs free energy (ΔGH, ∼0 eV). By analyzing the density of states, both Ru and S sites had greater H* intermediate absorption abilities. This study elaborates on the effect of preferential heteroatom substitution on photocatalytic performance and has widespread applications.

Construction of a Dual-Function Mo-ZIS@Ti for Photocatalytic Benzyl Alcohol Oxidation and Hydrogen Evolution Performance.

The photocatalytic oxidation of benzyl alcohol and the simultaneous evolution of hydrogen from water are efficient dual-optimal routes. It is important to develop composite catalysts that combine redox properties and facilitate electron-hole separation and transport. Herein, the bimetallic-doped Mo-ZIS@Ti photocatalyst was designed and synthesized, and the selective oxidation of benzyl alcohol and hydrogen evolution by water splitting was realized at the same time. Under visible light irradiation, benzyl alcohol was completely converted with more than 99% selectivity for benzaldehyde, and the H2 production rate was 5.6 times higher than the initial ZIS. The exceptional catalytic performance was ascribed to utilizing Ti-MIL-125 as a precursor, wherein slowly releasing-doped Ti formed robust Ti-S bonds that quickly transfer electrons and reduce sites. Meanwhile, doping Mo effectively captures photogenerated holes and acts as active sites for oxidation reactions. Both experimental characterization and work function calculations demonstrate that the bimetallic synergism effectively modulates the electronic structure of ZIS, promotes the directional separation of electrons and holes, and significantly improves the photoactivity and stability of ZIS. This work contributes a route to obtain benzaldehyde and green hydrogen at the same time and also gives new insights for the construction and mechanism study of bimetallic-doping catalysts.

Unique construction of hierarchical PANI–based nanofibrous network for boosting water electrolysis through highly efficient utilization of Pt nanocatalyst

Enhancing catalytic activity of Pt and designing rational structure of catalytic layer (CL) are effective strategies for improving the performance of proton exchange membrane water electrolysis (PEMWE) with lower Pt loading. Herein, a hierarchical nanostructured CL based on co–doped carbon, sulfonated polyaniline (PANI) nanofibrous network and Pt nanoparticles is constructed on carbon cloth by layer–by–layer in–situ growth method. The N/P/S co–doped carbon interlayer derived from PANI can promote the growth of sulfonated PANI nanofibers. The in–situ grown Pt nanoparticles is anchored by sulfonated PANI, achieving uniform and stable distribution as well as altered electronic structure for improved catalytic activity. The unique CL greatly improves the electrochemical surface area and provides interconnected pathways. The as–prepared cathode exhibits an overpotential of 23 mV at 10 mA cm−2, indicating excellent hydrogen evolution performance. Furthermore, the PEMWE device with above–mentioned cathode achieves an excellent performance of 1.771 V @ 2 A cm−2 with low Pt loading of 0.07 mg cm−2, which is comparable to that of the conventional cathode with 14 times higher Pt loading of 1 mg cm−2. Our strategy of designing hierarchical nanostructured CL provides a feasible approach to lower the consumption of Pt without performance loss for further industrialization of PEMWE.

Acid etching-induced nanocutting of LaNiO3 transplanting self-assembled photodiode array-like LaNiO3/N,P-RGO nanoreactor for efficient photocatalytic hydrogen evolution

Nanoscale graphene-semiconductor composite photocatalysts with fascinating properties in the photocatalytic hydrogen evolution have inspired numerous interests in broad research fields. The architectures with efficient light response and promoting charge separation at the interface between reduced graphene oxide (RGO) and semiconductor are critical, yet synthesizing them remains a formidable challenge. Herein, the photodiode array-like LaNiO3/N,P-RGO (LNO/N,P-RGO) nanoreactor was constructed using an innovative strategy of acid etching-induced nanocutting self-assembly. Ammonium dihydrogen phosphate working as both a nitrogen phosphorus co-dopant and an acid etching reagent, cuts perovskite LaNiO3 (LNO) nanoparticles into nanorods, which are bonded evenly on the nitrogen phosphorus co-doped reduced graphene oxide (N,P-RGO) to form an n-n semiconductor heterojunction LNO/N,P-RGO as a photodiode array-like nanoreactor via hydrothermal treatment. The photodiode array-like nanostructure exposes more active sites that are conducive to light absorption. The robust Ni-C and P-O bonds promote the narrowing of space-charge region at the interface by UV irradiation, thereby improving the transport of photogenerated carriers by visible light irradiation. The LNO/N,P-RGO nanoreactor exhibits excellent photocatalytic hydrogen evolution performance with a yield of up to 354 μmol g−1 h−1 under UV–visible light, which is 50 times higher than that of pure perovskite LNO, and it also displays favorable recycling stability.

Boosted photocatalytic performance of hydrogen evolution and formaldehyde degradation with a S-scheme PMo12/MgIn2S4 heterojunction

Fabrication of a S-scheme heterojunction with staggered energy band structures can accelerate the charge separation and retain high redox potentials. Herein, a series of x wt% H3PMo12O40/MgIn2S4 (abbr. x% PMo12/MIS; x = 7.5, 10.0, 12.5, 15.0 and 17.5) S-scheme heterojunctions were successfully constructed by a hydrothermal technology and exhibited efficient and durable visible-light-driven photocatalytic properties of H2-evolution and formaldehyde (HCHO) degradation. Particularly, the 12.5 % PMo12/MIS sample represented the optimal H2 evolution rate of 232.53 μmol·g−1·h−1 with the apparent quantum efficiency (AQE) value of 1.52 % (λ = 420 nm), and HCHO removal rate of 64.20 % in 60 min. Moreover, the intermediate products formed during the removal process of HCHO were revealed through in situ DRIFTS method. The superior photocatalytic activities mainly stemmed from the enhanced absorption of visible light, and effective separation of photoinduced charge carriers. Furthermore, the S-scheme photocatalytic mechanism for PMo12/MIS system was confirmed via in situ irradiated X-ray photoelectron spectroscopy, radical capturing tests and electron spin resonance data, and semiconductor energy band theory. The current study affords a valuable perspective for fabricating highly efficient S-scheme heterojunction photocatalysts for hydrogen evolution and HCHO elimination.

3D printed CuFe2O4 electrode with dominant facet (111) for boosting hydrogen evolution performance

The utilization of hydrogen energy is an important way to low carbon economy, and the development of active electrodes is the most critical step for efficient hydrogen evolution reaction. With the addition of KNO3 as a capping agent, the exposed crystal facet of CuFe2O4 is regulated, and the crystal facet (111) becomes dominant. Compared to CuFe2O4 (3 1 1), CuFe2O4 (111) exhibits low barrier of water dissociation and suitable *H binding strength, resulting in high intrinsic activity. Furthermore, the 3D printed electrodes show more excellent performance. At 3D printed CuFe2O4 (111) electrode, the overpotential is only 152 mV (vs. reversible hydrogen electrode) at 100 mA cm−2, and Tafel slope is as low as 33 mV dec-1. In addition, 3D printed CuFe2O4 (111) electrodes shows high stability. The superior performance of 3D printed CuFe2O4 (111) electrodes originates from high intrinsic activity and more exposed active sites. This study provides a new path for the development of efficient, stable and inexpensive monolithic catalyst electrodes for alkaline hydrogen evolution.

Retraction Note: Visible light-enhanced photocatalytic dye degradation and hydrogen evolution performance of BiVO4 thin films prepared at various annealing temperatures

Retraction Note: Visible light-enhanced photocatalytic dye degradation and hydrogen evolution performance of BiVO4 thin films prepared at various annealing temperatures

Ameliorating the electronic environment of NiCoP by halogen doping: A strategy for boosting hydrogen evolution performance

The design of highly efficient and robust non-noble metal water splitting catalysts for hydrogen production is crucial to reduce overpotential and energy consumption. Herein, a strategy for in-situ growth of halogen-doped NiCoP (X-NiCoP/NF, X = F, Cl, and Br) catalysts with special morphology on nickel foam is proposed. Both the experimental results and theoretical calculations reveal that the downshift of the d-band center energy can regulate the charge distribution of NiCoP owing to doping of strong electronegativity halogen, thus optimizing the Gibbs free energy of H* absorption (△GH*). The F-NiCoP/NF catalyst achieves remarkable HER activity under alkaline conditions, with overpotential at 10 mA cm−2 (η10) of 59 mV and Tafel slope of 48.9 mV dec−1 in 1.0 M KOH. Moreover, F-doping significantly increases the electrochemically active surface area (ECSA) and turnover frequency (TOF), suggestive of the F promotes the formation of highly dispersed high intrinsic active sites. The F-NiCoP/NF exhibits excellent stability with a negligible decrease in activity after durability tests. This work sheds light on the facile synthesis of highly active and stable catalysts with strong electronegative atom doping for HER.

Uniaxial Magnetization and Electrocatalytic Performance for Hydrogen Evolution on Electrodeposited Ni Nanowire Array Electrodes with Ultra-High Aspect Ratio.

Ni nanowire array electrodes with an extremely large surface area were made through an electrochemical reduction process utilizing an anodized alumina template with a pore length of 320 µm, pore diameter of 100 nm, and pore aspect ratio of 3200. The electrodeposited Ni nanowire arrays were preferentially oriented in the (111) plane regardless of the deposition potential and exhibited uniaxial magnetic anisotropy with easy magnetization in the axial direction. With respect to the magnetic properties, the squareness and coercivity of the electrodeposited Ni nanowire arrays improved up to 0.8 and 550 Oe, respectively. It was also confirmed that the magnetization reversal was suppressed by increasing the aspect ratio and the hard magnetic performance was improved. The electrocatalytic performance for hydrogen evolution on the electrodeposited Ni nanowire arrays was also investigated and the hydrogen overvoltage was reduced down to ~0.1 V, which was almost 0.2 V lower than that on the electrodeposited Ni films. Additionally, the current density for hydrogen evolution at -1.0 V and -1.5 V vs. Ag/AgCl increased up to approximately -580 A/m2 and -891 A/m2, respectively, due to the extremely large surface area of the electrodeposited Ni nanowire arrays.