Electrodes For Water Splitting Research Articles

Electrocatalyst‐Hydrogel Polymer Nanocomposite Thin Films for Water Splitting

AbstractRealization of scalable technologies for key processes like electrochemical water splitting requires the development of sustainable, efficient and cost‐effective catalytic electrodes. The innumerable electrocatalysts being developed in contemporary research rely on the use of a limited choice of binders for effective deployment in the electrolysis setting. Recent studies have demonstrated the utility of electrically insulating hydrogel polymers as suitable matrices for incorporating the electrocatalyst nanoparticles; the nanocomposite thin films coated on conducting substrates mediate highly efficient electrocatalytic water splitting reactions through the effective confinement of the electrolyte within and release of the gaseous products. After a brief introduction to the basic challenges in the field and the existing approaches that address them, this article outlines the promise of hydrogel based nanocomposite thin films in developing efficient and sustainable catalytic electrodes for water splitting, and their functional role in enhancing the efficiency of the electrochemical process. Directions for further development in this domain are noted.

A Search for Suitable Water-Splitting Electrodes Using SEAL and Harpoon

The search for suitable electrodes for photoelectrochemical water splitting extends across the periodic table. While III-V semiconductors exhibit superior light gathering properties, metal oxide semiconductors generally cost less and are more robust.The Solar Energy Activity Laboratory (SEAL) 1 and the Heterogeneous Anodes Rapidly Perused for Oxygen Overpotential Neutralization (HARPOON)2 are simple experiments that can quickly scan for suitable oxide semiconductors. The SEAL experiment measures photocurrent and the HARPOON experiment measures oxygen production efficiency.Electrodes made of oxides of Fe, Pd, In, Ni, Zn, Cd, Ga, and W were produced in our laboratory and evaluated using the SEAL and HARPOON experiments. The relative performance of these oxides and their mixtures were evaluated.REFERENCES J. R. McKone et al., “The Solar Army: A Case Study in Outreach Based on Solar Photoelectrochemistry, “ Rev. Adv. Sci. Eng. 3, 288 (2014).S. E. Shaner et al., “Discovering Inexpensive, Effective Catalysts for Solar Energy Conversion: An Authentic Research Laboratory Experience,” J. Chem. Educ. 93, 650 (2016).

MoOx/CoMo on Cu Nanowires as an Efficiently Bifunctional Electrocatalyst for Overall Water Splitting

AbstractElectrocatalytic water splitting is a promising approach for sustainable hydrogen production. The design and development of efficient and stable bifunctional catalysts are the key to realizing hydrogen production from water splitting. Herein, we successfully synthesized bifunctional MoOx/CoMo grown on copper nanowires (Cu NWs) through an electrodeposition approach, showing excellent hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performances. The MoOx/CoMo/Cu NWs catalyst exhibited overpotentials as low as 56 mV and 211 mV to deliver a current density of 10 mA cm−2 for HER and OER in alkaline media, respectively. Moreover, the MoOx/CoMo/Cu NWs as bifunctional electrodes for overall water splitting achieved a low voltage of 1.45 and 1.62 V at 10 and 50 mA cm−2, respectively, with a stability of 10 h at 50 mA cm−2. This work provides a promising strategy for designing highly active catalysts that replace precious‐metal‐based catalysts on energy conversion.

Phytogenic Cu2OBi2O3ZrO2 nanomaterial for supercapacitor and water splitting: Synthesis, characterization, and energy applications

Copper-based nanocomposites are regarded as sustainable energy materials having tremendous potential for energy storage supercapacitors and energy generation water splitting applications. Herein, a facile Cu-based ternary Cu2OBi2O3ZrO2 nanocomposite is prepared by a sustainable, lower-cost, and simple hydrothermal-based phyto-synthesis route by using Amaranthus Viridis L. amaranthaceae plant (abbreviated as AVL.A). The synthesized AVL.A-Cu2OBi2O3ZrO2 nanocomposite is characterized by powder-X-ray diffraction and FE-Scanning electron microscopy for its phase composition and surface morphology. The electrochemical efficiency of AVL.A-Cu2OBi2O3ZrO2 nanocomposite is investigated for supercapacitors and overall water splitting. The fabricated Cu2OBi2O3ZrO2 nanocomposite-based Nickel foam (NF) electrode shows superior performance with a specific capacitance of 524.5 F/g at 2 mV/s and 400 F/g at 1 A/g. The excellent rate capability is observed at scan rates from 2 mv/s to 300 mV/s and at current densities from 0.5 A/g to 30 A/g for AVL.A-Cu2OBi2O3ZrO2–NF. Furthermore, fabricated AVL.A-Cu2OBi2O3ZrO2–NF shows excellent electrochemical stability with 100% Coulombic efficiency till 5000 charge-discharge cycles. As bifunctional electrocatalyst AVL.A-Cu2OBi2O3ZrO2–NF electrode exhibits 117 mV overpotential at 10 mA/cm2 current density for HER kinetics along with 112 mV/dec Tafel slope values. The same Tafel slope value is also observed for OER measurements. These values of overpotential and Tafel slope for AVL.A-Cu2OBi2O3ZrO2–NF suggest a rapid and efficient electrochemical process of AVL.A-Cu2OBi2O3ZrO2–NF bifunctional electrocatalyst for energy generation. Overall study highly proposed AVL.A-Cu2OBi2O3ZrO2–NF as the potential electrode for energy storage supercapacitor and energy generation overall water splitting.

Synergistically coupled CoMo/Fe2O3 electrocatalyst for highly efficient and stable overall water splitting

Constructing bifunctional non-precious metal electrocatalysts with advanced industrial value and excellent electrocatalytic performance to achieve efficient overall water splitting is important but difficult. Herein, a heterogeneous electrocatalyst comprising of CoMo alloys anchored Fe2O3 nanosheets was prepared by hydrothermal and electrodeposition methods. The strongly coupled interfaces between the CoMo alloys and Fe2O3 nanosheets promote charge redistribution, which could improve electron transfer efficiency and accelerate reaction kinetics, potentially optimizing reactant adsorption energy. Further density functional theory (DFT) calculations reveal that the construction of CoMo/Fe2O3/NF heterostructured catalyst facilitates to promote interfacial charge redistribution and enhance charge transfer capacity, thus boosting the catalytic performance. Benefiting from this, the optimal CoMo/Fe2O3/NF heterostructure demonstrates a minimal overpotential of 71 mV at 10 mA cm−2 for the HER and 266 mV at 50 mA cm−2 for the OER. Remarkably, the catalyst served as a bifunctional electrode for water splitting, resulting in a cell voltage down to 1.5 V at a current density of 10 mA cm−2. This research provides an effective way for the construction of non-precious iron oxides-based bifunctional electrocatalysts using alloy/metal oxide interfacial engineering strategy.

Synthesis of MS2 (M=Mo, W) thin films by chemical solution deposition

MoS2 and WS2 as typical two-dimensional transition metal dichalcogenides have been investigated since of rich physicochemical properties. To deposit MoS2 and WS2 thin films, chemical solution deposition as a facile route had been used showing the advantages of high component controllability, low cost, sequential processing of device, easy preparation of large-size films and facile preparation of films on irregular substrates. Here, Mo1-xWxS2 (0 ≤ x ≤ 1) thin films were successfully prepared by chemical solution deposition method. The phases as well as microstructures were investigated using field emission scanning electron microscope, atomic force microscopy, transmission electron microscopy, Raman and x-ray photoelectron spectroscopy measurements. The prepared Mo1-xWxS2 thin films are used as hydrogen evolution reaction (HER) catalyst electrodes for water splitting. The Mo0·3W0·7S2 thin film catalyst shows an overpotential of 345 mV at a current density of 10 mA cm−2 and the corresponding Tafel slope of 169 mV dec−1 in 0.5 M sulfuric acid. The results will provide a facile method to deposit MX2 thin films.

Interfacial electronic modulation of NiCo decorated nano-flowered MoS2 on carbonized wood as a remarkable bifunctional electrocatalyst for boosting overall water splitting

The development of a cost-effective and efficient bifunctional electrode for overall water splitting holds significant importance in accelerating the sustainable advancement of hydrogen energy. The present study involved a bifunctional catalytic electrode was prepared by loading NiCo-modified 1T/2H MoS2 onto carbonized wood (NiCo-MoS2-CW) using the hydrothermal and electrodeposition techniques. The XPS analysis revealed that NiCo-modified MoS2 exhibited a weak electron characteristic, which facilitated the ionization of H2O and significantly enhanced the Volmer step. The XPS analysis unveiled that NiCo-modified MoS2 displayed a weak electron characteristic, thereby promoting the ionization of H2O and substantially augmenting the Volmer step. The electrocatalytic performance of the NiCo-MoS2-CW in 1.0 M KOH is remarkably impressive, exhibiting minimal overpotentials of only 64 mV (10 mA cm−2) and 216 mV (50 mA cm−2) for the hydrogen evolution reaction and oxygen evolution reaction, respectively. The NiCo-MoS2-CW || NiCo-MoS2-CW electrolytic cell can achieve a cell voltage of only 1.69 V to achieve a current density of 50 mA cm−2. Overall, this study proposes a potential approach to improve the catalytic efficiency of overall water splitting by modulating the interfacial electronic properties of MoS2.

Fabrication of covellite supported spinel oxide CuCo2O4 hybrid nano-composite electrode for efficient overall water splitting

Hydrogen fuel being a green source of energy got attention as no harmful by-products are produced on its combustion. Hydrogen generation by water splitting via effective electrocatalyst is imperative. This study reports the synthesis of CuCo2O4 supported on CuS via hydrothermal technique and use it as electrocatalyst for hydrogen generation. Electrocatalysis using CuS/CuCo2O4 electrode in alkaline media, shows remarkably low overpotential of 286 and 135 mV at benchmark current density of 10 mA cm−2 for oxygen evolution and hydrogen evolution reactions (OER and HER), respectively. Strain and dislocation cause more defects in composite leading to increase in active sites. Modest Tafel value of 170 and 61 mV/dec for HER and OER, accordingly suggesting improved electrocatalytic efficiency and reaction kinetics of CuS/CuCo2O4 nano-composite. The CuS/CuCo2O4 nano-composite also shows higher values of TOF and electronic conductivity than CuS and CuCo2O4. Evaluation of durability over a 50-hour period shows little current loss, demonstrating that the generated nanocomposite’s remarkable stability and it also shows high electrocatalytic active surface area (139.6 cm−2).

One-step electrodeposition synthesis of NiFePS on carbon cloth as self-supported electrodes for electrochemical overall water splitting

Electrocatalytic water splitting (EWS) for hydrogen production is considered an ideal strategy for utilizing renewable energy, reducing fossil fuel consumption, and addressing environmental pollution issues. Traditional noble metal electrocatalysts have excellent performance, but their cost is high. Developing efficient, stable, and relatively inexpensive dual functional electrocatalysts is crucial for promoting large-scale EWS hydrogen production processes. Herein, a simple one-step electrodeposition method was used to grow nickel–iron phosphorus-sulfides (NiFePS) on the surface of hydrophilic treated carbon cloth (CC). The resultant NiFePS/CC with a phosphorus to sulfur ratio of 1:4 exhibited the best electrocatalytic performance, requiring only −91 mV and 216 mV overpotentials to generate the current densities of 10 mA·cm−2 in hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively. When it was used as a bifunctional electrocatalyst to overall water splitting (OWS), a voltage of 1.536 V can generate a current density of 10 mA·cm−2. The excellent electrocatalytic performance can be ascribed to two factors: 1) the CC with excellent conductivity serves as a growth substrate, reducing the impedance of charge transfer from the electrode to the electrolyte and accelerating the electron transfer rate; 2) The large number of ultra-thin nanosheets formed on the surface of the catalyst increase the electrochemical specific surface area, expose more reaction sites, and thus improve the electrocatalytic reaction performance. This work provides a new approach for designing efficient non-noble metal electrocatalysts for water splitting.

The decoration of NiFe layered-double-hydroxide/NiFe nanoalloy grown in a corrosion-cell by MoS2 nanosheets as a binder-free electrode for efficient overall water splitting

Nickel-Iron layered double hydroxides (NiFe-LDH) prepared by corrosion engineering has been proven effective for electrochemical overall water splitting, but the growth mechanism is still controversial. In this work, nano-Fe (0) powder was used as the iron substrate to produce NiFe nanoalloy under corrosion conditions as the corrosion-cell cathode, and then NiFe-LDH nanosheets were deposited. The NiFe-LDH/NiFe nanoalloy particles were captured on carbon cloth by a "network" structure by interlacing MoS2 layers, creating a binder-free self-supporting electrode (MoS2/NiFe-LDH/NF-NP/CC). The MoS2/NiFe-LDH/NF-NP/CC exhibited excellent overall water splitting performance, with a current density of 10 mA cm−2 at a voltage of only 1.52 V, owing to the abundant HER active sites at the edge of MoS2 nanosheets, the high conductivity and OER properties of the NiFe-LDH/NiFe nanoalloy, as well as the effective 3D heterojunction structure.

Rechargeable zinc-water battery for sustainable hydrogen generation

Metal-water primary batteries hold promise for distributed hydrogen production but suffer from limited renewability of metal electrodes in aqueous electrolytes. Here, we introduce a novel concept of a rechargeable zinc-water battery featuring a reversible zinc anode paired with a bifunctional water electrolysis electrode, realized in a specially designed aqueous electrolyte-a mild zinc triflate aqueous electrolyte with the addition of ethylenediaminetetraacetic acid disodium (EDTANa2). The system enables high-purity hydrogen production during discharge and high-purity oxygen production during charge in a membrane-free setup. In the zinc-water battery, EDTANa2 enhances the water-splitting electrode's performance by replacing hydrophobic OTF- anions, ensuring optimal water activity. Additionally, EDTANa2 enhances Zn electrode reversibility by chelating Zn2+, preventing solvated water decomposition during zinc deposition. This integrated battery continuously undergoes charge-discharge cycles for over 55 h at a current density of 6 mA cm-2. Moreover, it achieves a high hydrogen evolution rate of 12.5 mL cm-2 h-1, enabling cost-effective, high-purity hydrogen production without expensive membranes. These findings open new avenues for sustainable hydrogen generation and energy storage in nano energy systems.

Porous TiN-based ceramic electrode with N-modified Co-based Nanorods/TiN heterointerfaces for efficient overall water splitting

The development of high-performance electrocatalytic electrodes for overall water splitting is a crucial issue to realize renewable hydrogen production. This paper presents the in situ growth of N-modified Co-based nanorods on porous TiN ceramic membranes using the hydrothermal method and thermal NH3 treatment, resulting in a novel self-supported electrocatalytic electrode with abundant heterointerfaces, denoted as NCTN-x-y (x: nitridation temperature; y: nitridation time). In the alkaline medium (1 M KOH), the NCTN-350-2 electrode displays the best hydrogen evolution reaction (HER) activity (ƞ10 = 66 mV), and the NCTN-250-3 electrode manifests the best oxygen evolution reaction (OER) performance (ƞ10 = 270 mV). Accordingly, these two electrodes comprise an electrolyzer, which features a current density of 10 mA cm−2 at a low cell voltage of 1.63 V. The good electrocatalytic performance can be attributed to the abundant heterointerfaces formed between the porous TiN ceramic membrane and the N-modified Co-based nanorods, in conjunction with the hierarchical pore structure of the TiN ceramic membrane. Theoretical calculations identify that the construction of heterointerfaces modulates the electronic structure of active sites, thereby promoting the dissociation of H2O, optimizing the H* adsorption energy (ΔGH*), and accelerating the reaction kinetics, which ultimately improve the electrocatalytic activity of electrode.

A nickel-based dendritic electrode matrix with high surface efficiency mass transfer for highly efficient overall water splitting

Electrodes are key components in water splitting. Owing to their porous structures, commercial foam metal electrode matrices can provide numerous active sites. However, the complex and disordered surface structure impedes the release of the generated gas bubbles, and sluggish mass transfer usually becomes a bottleneck in the electrochemical reaction kinetics. For this purpose, this study proposes a pulse-jet electrodeposition method for the preparation of nickel-based dendritic electrode matrices (NDEM). This research shows that the electrode matrix prepared under the conditions of V = 26 V, PW = 10 μs, and PI = 35 μs has a unique surface structure, which can quickly release bubbles, effectively attract ions, and accelerate mass transfer on the electrode surface, resulting in excellent electrochemical performance. After loading the catalyst, the NDEM requires only 1.552 V to reach a current density of 10 mA cm−2. At an electrolysis voltage of 2.5 V, the hydrogen production was 45% higher than that of the NF electrode, and it had excellent stability. This study opens a new avenue for the design of highly efficient and low-cost electrodes for water splitting.

Heterogeneous strategy constructing a built-in electric field: CoP/FeP bifunctional electrode for overall water splitting

Development of non-noble bifunctional electrocatalysts for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are of great significance under alkaline electrolytes for overall water splitting. In this work, CoP/FeP has been designed and constructed in situ on carbon fiber paper by using the bimetallic metal organic frameworks (MOFs) synthesis strategy. The heterogeneous CoP/FeP displays excellent catalytic activities in both HER and OER of the fully hydrolyzed semi-reaction. Remarkably, CoP/FeP is applied as the bifunctional electrode in anode and cathode to construct an overall water splitting apparatus, resulting in the low cell voltage and excellent stability. The exceptional electrocatalytic performance may be mainly attributed to the heterogeneous interface, which constructs a built-in electric field to provide electron to Co with electron-rich structure, resulting in the strong adsorption of H and weak adsorption of O2 on Co. This study provides an effective and controllable method for the design of self-supporting bimetal phosphide catalysts.

RuSe2 and CoSe2 Nanoparticles Incorporated Nitrogen-Doped Carbon as Efficient Trifunctional Electrocatalyst for Zinc-Air Batteries and Water Splitting.

The development of affordable, highly active, and stable trifunctional electrocatalysts is imperative for sustainable energy applications such as overall water splitting and rechargeable Zn-air battery. Herein, we report a composite electrocatalyst with RuSe2 and CoSe2 hybrid nanoparticles embedded in nitrogen-doped carbon (RuSe2CoSe2/NC) synthesized through a carbonization-adsorption-selenylation strategy. This electrocatalyst is a trifunctional electrocatalyst with excellent hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR) activities. An in-depth study of the effect of Se on the electrocatalytic process was conducted. Notably, the incorporation of Se moderately adjusted electronic structure of Ru and Co, enhancing all three types of catalytic performance (HER, η10 = 31 mV; OER, η10 = 248 mV; ORR, E1/2 = 0.834 V) under alkaline condition with accelerated kinetics and improved stability. Density functional theory (DFT) calculation reveals that the (210) crystal facet of RuSe2 is the dominant HER active site as it exhibited the lowest ΔGH* value. The in situ Raman spectra unravel the evolution process of the local electronic environment of Co-Se and Ru-Se bonds, which synergistically promotes the formation of CoOOH as the active intermediate during the OER. The superior catalytic efficiency and remarkable durability of RuSe2CoSe2/NC as an electrode for water splitting and zinc-air battery devices demonstrate its great potential for energy storage and conversion devices.

Electrocatalytic overall water splitting based on (ZnNiCoFeY)xOy high-entropy oxide supported on MoS2

Hydrogen energy is a sustainable and clean source that can meet global energy demands without adverse environmental impacts. High-entropy oxides (HEOs), multielement (5 or more) oxides with an equiatomic or near-equatomic elemental composition, offer a novel approach to designing bifunctional electrocatalysts. This work explores (ZnNiCoFeY)xOy over MoS2 as a bifunctional electrocatalyst (HEO–MoS2) in an alkaline medium. The HEO was synthesized using a combustion process and loaded over MoS2 using an ultrasonic method. The synthesized HEO over MoS2 exhibits excellent performance, including long-term stability for over 24 h, an overpotential of 214 mV vs the reversible hydrogen electrode (RHE) for the hydrogen evolution reaction (HER), and 308 mV for the oxygen evolution reaction (OER) at 10 mA cm−2. This bifunctional electrocatalyst exhibits low overpotential for both the HER and the OER at high current densities. Additionally, HEO–MoS2 demonstrates smaller solution and charge transfer resistance values. The electrolyzer was assembled using bifunctional HEO–MoS2 electrodes for overall water splitting. These electrodes exhibited a low cell voltage of 1.65 V at 10 mA cm−2. The novel electrocatalyst was fabricated using a facile and scalable method that appeals to industrial applications.

Superhydrophilic 3D amorphous/crystalline heterostructure: Nanosheets-assembled CoMoP-FexP/NF as efficient bifunctional electrodes for alkaline water splitting

To push forward the hydrogen energy technology, it is crucial to develop a highly active catalyst for the application of water splitting. Nevertheless, many electrocatalysts suffer from functional limitations, making them unsuitable for both anode and cathode applications. Therefore, the utilization of bifunctional electrocatalysts is necessary to overcome this limitation. In this study, we have reported a bifunctional CoMoP-FexP/NF catalyst with favorable electrocatalytic performance toward hydrogen evolution reaction/oxygen evolution reaction (HER/OER). Balanced amorphous/crystalline heterophase endows CoMoP-FexP/NF with more exposed active sites. In addition, the superhydrophobic nature of CoMoP-FexP/NF helps to improve the contact with electrolyte. Following conditional optimization, CoMoP-FexP/NF requires only an overpotential of 85.6 mV to achieve a current density of 10 mA cm−2 for HER, and 249.6 mV for a current density of 20 mA cm−2 for OER. A water-splitting electrolyzer comprising CoMoP-FexP/NF requires a low cell voltage of 1.56 V to achieve a current density of 10 mA cm−2. This study provides valuable insights into designing bifunctional electrocatalysts and replacing noble metallic materials to enhance hydrogen production from water splitting.

Rational design of bimetallic metal-organic framework derived three-dimensional flower-like and porous NiCoFe LDH/NF electrocatalyst for electrochemical overall water splitting

Porous structured metal–organic frameworks (MOFs) and their derivatives are desired in catalysis and energy storage. Herein, three-dimensional (3D) flower-like NiCoFe LDH/NF are first synthesized though a convenient cathodic electrodeposition strategy subsequent an ion-exchange process. And the morphology and catalytic performance of the CoFe-MOF/NF can be finely by tailoring the electrodeposition voltage, deposition time and the ratio of Co: Fe. The 3D flower-like and porous NiCoFe/NF not only retains structural integrity to promote durability but also greatly alleviates the aggregation of active sites. In addition, the 3D flower-like and porous NiCoFe/NF display remarkable results with low overpotentials of 233 mV at a current density of 50 mA cm−2 for OER and 84 mV at a current density of 10 mA cm−2 for HER in 1 M KOH, respectively. When acting as electrocatalytic electrodes for overall water splitting, NiCoFe/NF displays a low overpotential of 1.52 V to achieve a current density of 10 mA cm−2. The study provides a promising approach to design MOF electrocatalysts for electrocatalytic applications.

Multiscale hierarchical nanoarchitectonics with stereographically 3D-printed electrodes for water splitting and energy storage

The pursuit of sustainable solutions to address the global energy crisis has led to a keen interest in the advancement of cost-effective and multifunctional electrochemical systems. These systems aim to achieve both zero-carbon emissions and the dual capability to convert and store energy efficiently. The electrochemical splitting of water is one way to create carbon–neutral, clean hydrogen gas. Electrocatalysis and hydrogen evolution in general depends not only on the catalyst but also on its nano- and microstructure, which influences local chemical conditions and hydrogen gas bubble detachment. Therefore, rapid screening of not only potential catalysts but also various structured surfaces is needed for effective electrode fabrication. The fused deposition modeling (FDM) method of 3D printing is frequently used for electrode fabrication using conducting filaments; however, its micro-structuration resolution is limited. Stereolithography can produce complex and fine structures; however, the resins are not conductive and therefore the structures are not suitable for electrode fabrication. In this work, we have fabricated a substrate with high-resolution needle array architecture using stereolithographic (SLA) 3D printing and coated it with Co3Te4-CoTe2 (COT) nanofiber for water splitting and energy storage. The SLA 3D-printed cobalt telluride electrodes showed appreciable performance as a photoelectrocatalyst for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), acting as a bifunctional catalyst. We also demonstrated fabrication of a cobalt telluride based SLA 3D-printed supercapacitor device with multiscale hierarchy. The SLA 3D-printed supercapacitor device exhibited good electrochemical behavior along with high cycling stability. In general, we show here a universal method for SLA conductive electrode fabrication with hierarchical structuring of functional elements and suitable for various applications.

MoVN-coated MoNi4-MoO2 nanorods as a bifunctional electrode for electrochemical water splitting

MoVN-coated MoNi4-MoO2 nanorods as a bifunctional electrode for electrochemical water splitting