Stability For Hydrogen Evolution Reaction Research Articles

Ball-milled MoS2 with graphene shows enhanced catalytic activity for hydrogen evolution reaction

ABSTRACT The hydrogen evolution reaction (HER) is an important phenomenon in water splitting. Consequently, the development of an active, earth-abundant, and inexpensive HER catalyst is highly desired. MoS2 has drawn considerable interest as an HER catalyst because it is composed of non-precious metal and exhibits high catalytic activity in the nanosheet form. In this study, size-controlled MoS2 particles were synthesized by ball milling. The as-prepared samples exhibited significantly enhanced electrochemical and catalytic properties compared to those of pristine bulk MoS2. Furthermore, the HER activity improved further upon the introduction of graphene into the as-prepared ball-milled samples. In particular, the MoS2 sample ball-milled for 12 h mixed with graphene exhibited optimal performance, showing an overpotential (160 mV at 10 mA cm−2) that was ~335 mV lower than that of pristine bulk MoS2. The superior catalytic activity was ascribed to the exposed edge sites, sulfur vacancies, and 1T phase of MoS2, as well as the noteworthy fortifying effect of the electronically conductive flexible material, graphene. The results provide a promising strategy for its application as an efficient and stable HER catalyst.

Pt-Decorated bimetallic PdRu nanocubes with tailorable surface electronic structures for highly efficient acidic hydrogen evolution reaction

Efficient and stable catalysts are crucial for green hydrogen production from acidic water splitting. Herein, using interface engineering, the surface electronic structures of bimetallic PdRu nanocubes have been significantly regulated by Pt atoms (PdRu@Pt). Interestingly, Pt atoms are located on the corners and facets of PdRu nanocubes, resulting in lattice tension and fast electron transfer. As a result, the obtained trimetallic PdRu@Pt nanocubes with an average size of 13 nm have exhibited highly enhanced catalytic activity and stability for hydrogen evolution reaction (HER) in acidic media, delivering 18 mV lower overpotential to reach a current density of 10 mA cm−2, and maintaining a remarkable long-term stability for up to 24 h. In particular, the lower overpotential of 489 mV at 500 mA cm−2 for PdRu0.04@Pt0.12 nanocubes indicates its potential for future industrial application in the future. Such enhancements in HER performance can be attributed to the highly facet-edge-exposed Pt atoms and the significant strain effects resulting from the introducing Pt atomic layers to PdRu surfaces.

Hierarchical multiphase heterointerfaces Ni2P–CoP/MoO2 catalyst for efficient and stable hydrogen evolution reaction over the entire pH range

The development of pH-versatile, high-performing, and durable catalysts for hydrogen evolution reaction (HER) is crucial to satisfy the complex environment of water electrolysis industry. Herein, we present the synthesis of a hierarchical multiphase heterointerfaces Ni2P–CoP/MoO2 nanocatalyst with exceptionally high HER activity in the entire pH range through a facile three-step process involved hydrothermal, electrodeposition, and in situ phosphating treatment. Experiments and characterization revealed the strong electronic interactions among the phases of Ni2P, CoP, and MoO2, which endowed the Ni2P–CoP/MoO2 with high hydrogen evolution activity in different pH ranges. Meanwhile, the layered structure of our as-prepared catalyst makes the massive exposure of active sites. As a result, the Ni2P–CoP/MoO2 catalyst shows remarkable performance, requiring mere overpotentials of 33, 41, and 23 mV to drive 10 mA cm−2 in 1 M KOH, 1 M phosphate buffer solution, 0.5 M H2SO4, respectively. Moreover, the catalyst exhibits excellent stability in the chronopotentialmetry test under different pH electrolyte. Impressively, the Ni2P–CoP/MoO2 catalyst coupled with Ni–Fe LDH to form an overall water splitting system only require 1.50 V to drive 10 mA cm−2. Furthermore, this system actuated by wind and solar energy can stably undergo a continuous production of hydrogen and oxygen.

Catalytic activity of Ni–Cr–Fe–Mo porous materials for hydrogen evolution reaction in alkaline media

The hydrogen evolution reaction (HER) based on water electrolysis represents an ideal approach for hydrogen production. The advancement of highly active non-precious metal catalysts holds paramount importance. This research employed powder metallurgy sintering to prepare Ni–Cr–Fe and Ni–Cr–Fe–Mo porous materials. It investigated the impact of Mo doping and sintering temperature on the catalytic activity and microstructural influence of hydrogen evolution materials. Furthermore, the materials' electrochemical performance and long-term stability in 6 mol/L KOH were examined. In complicated systems, the current work provides a feasible method for producing hydrogen from Ni–Cr–Fe–Mo porous materials in a strong alkali environment. The results exhibited that when Mo content is 5% and the sintering temperature is 800 °C, the porosity of Ni–Cr–Fe–Mo porous materials is up to 39.9% and the catalytic activity is up to 97%. At the same time, the current density decays to 7.1% after 1000 cycles of electrolysis and shows good HER stability after 48 h. The enhanced catalytic activity for hydrogen evolution emanated from the positive synergy among the transition metal elements.

Charge Redistribution of Lattice-Mismatched Co─Cu3P Boosting pH-Universal Water/Seawater Hydrogen Evolution.

Practical applications of the hydrogen evolution reaction (HER) rely on the development of highly efficient, stable, and low-cost catalysts. Tuning the electronic structure, morphology, and architecture of catalysts is an important way to realize efficient and stable HER electrocatalysts. Herein, Co-doped Cu3P-based sugar-gourd structures (Co─Cu3P/CF) are prepared on copper foam as active electrocatalysts for hydrogen evolution. This hierarchical structure facilitates fast mass transport during electrocatalysis. Notably, the introduction of Co not only induces a charge redistribution but also leads to lattice-mismatch on the atomic scale, which creates defects and performs as additional active sites. Therefore, Co─Cu3P/CF requires an overpotential of only 81, 111, 185, and 230mV to reach currents of 50, 100, 500, and 1000mA cm-2 in alkaline media and remains stable after 10 000 CV cycles in a row and up to 110h i-t stability tests. In addition, it also shows excellent HER performance in water/seawater electrolytes of different pH values. Experimental and DFT show that the introduction of Co modulates the electronic and energy level structures of the catalyst, optimizes the adsorption and desorption behavior of the intermediate, reduces the water dissociation energy barrier during the reaction, accelerates the Volmer step reaction, and thus improves the HER performance.

Bimetallic Nitride Ni3Mo3N Microrods with Abundant Catalytic Sites Used as Efficient Electrocatalysts for Hydrogen Evolution Reaction

The importance of efficient and stable hydrogen evolution reaction (HER) electrocatalysts for hydrogen production in alkaline conditions to energy crisis resolution and environmental pollution is immense. In general, the quantity of catalytic sites in the electrocatalyst limits the current density of HER. In response to such problems, the bimetallic effect of non-noble bimetallic nitrides has been shown to regulate the corresponding catalytic sites. Here, a microrod-like non-noble bimetallic nitride catalyst with Ni3Mo3N microrods uniformly modified on nickel foam was synthesized by hydrothermal and nitriding processes. The catalyst showed high catalytic activity for HER in 1 M KOH solution. The overpotential was only 28 mV at a current density of 10 mA·cm−2, demonstrating exceptional electrochemical performance. Furthermore, it exhibited remarkable long-term stability under the same current density. This work will open up a low-cost and simple way for the synthesis of bimetallic nitrides as functional electrode materials for HER and electrochemical detection.

Superior MoTiN and NiMoTiN coating electrode with platinum-like catalytic activity fabricated by plasma electrolytic oxidation

Electrolyzing water is an effective and feasible technology to achieve a large-scale hydrogen production in industry. However, it is still challenging to develop an efficient approach to fabricate a superior and stable hydrogen evolution reaction (HER) electrodes with low cost and outstanding catalytic efficiency. This work presents an innovative surface modification technique of plasma electrolytic oxidation (PEO) to fabricate superior MoN based coating electrodes. By simply introducing Na2MoO4 and NiAc2 into the electrolyte, a novel MoTiN and NiMoTiN coatings were successfully achieved on the surface of a titanium substrate by PEO and annealing treatments, which exhibits excellent mechanical adhesion and platinum-like catalytic properties. Importantly, it has been demonstrated that the newly formed MoTiN solid solution combined by active Mo2N and conductive TiN can contribute the superior catalytic activity and the subsequent Ni doping can effectively stabilize the structure and activity of MoTiN. Under the alkaline environment of 1 M KOH, the MoTiN and NiMoTiN coated electrodes require only 126 and 121 mV overpotential, respectively, to achieve a current density of 10 mA cm−2. Additionally, under the same test conditions, NiMoTiN can operate stably for over 24 h, demonstrating excellent HER catalytic activity and stability. This work provides new insights into the preparation of HER electrodes with superior mechanical properties and excellent catalytic performance towards industrial hydrogen production.

Interface engineering of hierarchical flower-like N, P, O-doped NixPy self-supported electrodes for highly efficient water-to-hydrogen fuel/oxygen conversion

Rational construction of efficient bifunctional catalysts with robust catalytic activity and durability is significant for overall water splitting (conversion between water and hydrogen fuel/oxygen) using non-precious metal systems. In this work, the hierarchically porous N, P, O-doped transition metal phosphate in the Ni foam (NF) electrode (hollow flower-like NPO/NixPy@NF) was prepared through facile hydrothermal method coupled with phosphorization treatment. The hierarchical hollow flower-like NPO/NixPy@NF electrodes exhibited high bifunctional activity and stability for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in alkaline solutions. The optimized electrode showed low overpotentials of 76 and 240 mV for HER and OER to reach a current density of 10 mA cm−2, respectively. Notably, the NPO/NixPy@NF electrode only required a low voltage of 1.99 V to reach the current densities of 100 mA cm−2 with long-term stability for overall water splitting using the NPO/NixPy@NF|| NPO/NixPy@NF cell, surpassing that of the Pt/C-RuO2 (2.24 V@ 100 mA cm−2). The good catalytic and battery performance should be attributed to i) the open hierarchical structure that enhanced the mass transfer; ii) a highly conductive substrate that accelerated the electron transfer; iii) the rich heterojunction and strong synergy between Ni2P and Ni5P4 that improved the catalytic kinetic; iv) the proper-thickness amorphous phosphorus oxide nitride (PON) shell that realized the stability. This work demonstrates a promising methodology for designing bifunctional transition metal phosphides with high performance for efficient water splitting.

Porous tungsten carbo-nitride supported Pt nanoparticles with high conductivity for efficient and stable hydrogen evolution reaction

Designing low-cost catalysts that offer both high mass activity and high cycling stability is crucial. Herein, a binder-free 3D self-supporting electrode composed of carbo-nitride tungsten supporting Pt nanoparticles (Pt@3DP-WNxC1-x/W) has been successfully synthesized for hydrogen evolution reaction in acid electrolyte. The tungsten carbo-nitride synthesized via a one-step heat treatment exhibits enhanced conductivity as a result of the carbonization process and optimizes the adsorption and desorption properties of WC towards H atoms through the incorporation of N atoms, thereby achieving an effective balance. Simultaneously, the N–Pt bond enhances electron transfer efficiency. This electrode exhibits outstanding electrochemical performance with a 219 mV overpotential at a current density of −300 mA cm−2. Its current density and mass activity is up to 75 mA cm−2 and 7.5 A·mgPt−1 at an overpotential of 100 mV, respectively, which are both 2.6 times higher than those of the 40% Pt/C electrode. In addition, it reveals a low Tafel slope of 38.3 mV dec−1 indicating rapid kinetics. Furthermore, the electrocatalyst shows only 3 mV day at −100 mA cm−2 after 10,000 cycles. Both theoretical calculation and experimental results show the promotion of catalytic efficiency of Pt@3DP-WNxC1-x/W brought by carbo-nitrition. This study offers a novel, efficient, and stable electrode design strategy.

Amorphous-crystalline transition-driven synthesis of Co single-atom catalysts on MoO3 for enhanced hydrogen evolution in acidic and alkaline media

Single atom catalysts (SACs) dispersed in metal oxide supports offer not only maximized catalyst utilization but also extended modulation capabilities through interactions between the SA and its support. However, achieving facile preparation and ensuring electrochemical durability of such SACs, particularly for hydrogen evolution reaction (HER) applications, remain formidable challenges. Our study addresses these issues by employing an amorphous-to-crystalline phase transition in MoO3 to synthesize a cobalt (Co) SA catalyst. This method facilitates the production of highly selective SA catalysts at low temperatures and ensures their enhanced stability in HER applications. The Co SA MoO3 catalyst exhibits superior performance in HER, operating effectively in both acidic and alkaline environments. Significantly, it maintains stable HER activity across these diverse electrolytic conditions. Our Density Functional Theory (DFT) calculations provide insights into the exceptional HER performance of Co SA MoO3. These calculations reveal that the strong affinity for hydrogen and water, facilitated by the modulation of the p-band orbitals at specific oxygen sites adjacent to the Co SA, establishes a thermoneutral pathway for HER. This study represents a pivotal advancement, showcasing a highly practical and robust single-atom catalyst, marking a significant stride towards sustainable energy solutions.

MOCHAs: An Emerging Class of Materials for Photocatalytic H2 Production.

Production of green hydrogen (H2) is a sustainable process able to address the current energy crisis without contributing to long-term greenhouse gas emissions. Many Ag-based catalysts have shown promise for light-driven H2 generation, however, pure Ag-in its bulk or nanostructured forms-suffers from slow electron transfer kinetics and unfavorable Ag─H bond strength. It is demonstrated that the complexation of Ag with various chalcogenides can be used as a tool to optimize these parameters and reach improved photocatalytic performance. In this work, metal-organic-chalcogenolate assemblies (MOCHAs) are introduced as effective catalysts for light-driven hydrogen evolution reaction (HER) and investigate their performance and structural stability by examining a series of AgXPh (X=S, Se, and Te) compounds. Two catalyst-support sensitization strategies are explored: by designing MOCHA/TiO2 composites and by employing a common Ru-based photosensitizer. It is demonstrated that the heterogeneous approach yields stable HER performance but involves a catalyst transformation at the initial stage of the photocatalytic process. In contrast to this, the visible-light-driven MOCHA-dye dyad shows similar HER activity while also ensuring the structural integrity of the MOCHAs. The work shows the potential of MOCHAs in constructing photosystems for catalytic H2 production and provides a direct comparison between known AgXPh compounds.

In situ anchoring of Ni12P5 on ZnIn2S4 for efficient and stable photocatalytic H2 evolution

It is a great challenge to develop efficient, stable and inexpensive hydrogen evolution reaction (HER) catalysts for photocatalytic water-splitting. In this paper, Ni12P5 (NP) was in situ anchored on the surface of ZnIn2S4 (ZIS) via a solvothermal route with nickel chloride and red phosphorus as ingredients. Using triethanolamine as sacrificial agent, the photocatalytic hydrogen evolution activity of NP/ZIS was studied under visible light irradiation. At the same time, the composition, structure, morphology and photoelectrochemical properties of the as-obtained samples were analyzed through a sequence of characterization techniques. ZIS loaded with 6 wt% NP (6NP/ZIS) exhibits the best hydrogen evolution activity and excellent stability. The H2 evolution rate of 6NP/ZIS is 5.4 times higher than that of pristine ZIS and well beyond that of the physical mixture (6NP + ZIS) or even that of the optimal Pt/ZIS under the same conditions. The maximal apparent quantum yield (AQY) of 22.7 % at 400 nm is achieved, superior to the most reported performance of ZnIn2S4-based photocatalysts for HER. The anchor of NP can not only enhance the visible light absorption intensity, but also reduce the HER overpotential. More importantly, the intimate interface between ZIS and NP can promote the separation and migration of photo-excited carriers, thereby enhancing the activity of photocatalytic hydrogen evolution. The possible photocatalytic reaction mechanism was discussed.

Ni─Co─O─S Derived Catalysts on Hierarchical N-doped Carbon Supports with Strong Interfacial Interactions for Improved Hybrid Water Splitting Performance.

Simultaneously improving electrochemical activity and stability is a long-term goal for water splitting. Herein, hierarchical N-doped carbon nanotubes on carbon nanowires derived from PPy are grown on carbon cloth, serving as a support for NiCo oxides/sulfides. The hierarchical electrodes annealed in N2 or H2/N2 display improved intrinsic activity and stability for hydrogen evolution reaction (HER) and glucose oxidation reaction. Compared with Pt/C||Ir/C in alkaline media, the glucose electrolysis assembled with electrodes exhibits a cell voltage of 1.38V at 10mAcm-2, durability for >12h at 50mAcm-2, and resistance to glucose/gluconic acid poisoning. In addition, electrocatalysts can also be applied in ethanol oxidation reactions. Systematic characterizations reveal the strong interactions between NiCo and N-doped carbon support-induced partial charge transfer at the interface and regulate the local electronic structure of active sites. Density functional theory calculations demonstrate that the synergistic effect between N-doped carbon supports, metallic NiCo, and NiCo oxides/sulfides optimize the adsorption energy of H2O and the H* free energy for HER. The energy barrier of the dehydrogenation of glucose effectively decreased. This work will attract attention to the role of metal-support interactions in enhancing the intrinsic activity and stability of electrocatalysts.

Construction of Z-type In2O3@InP heterostructure with enhanced photo-assisted electrocatalytic water splitting for hydrogen production

We report an in-situ construction strategy of Z-type In2O3@InP hydrogen evolution reaction (HER) electrocatalyst with well-defined core-shell structure on nickel foam (In2O3@InP/NF) via sequential hydrothermal, annealing, and phosphating steps. The phosphating time dramatically affects the morphology, crystal phase, elemental composition, and optical properties of In2O3@InP. The resulting electrode obtained with 2 h of phosphating time has smaller overpotentials and Tafel slope, larger TOF and ECSA, and lower charge transfer resistance compared to In2O3/NF. The better activity reveals the promoted roles of InP that can provide more active sites, facilitate charge transfer, and accelerate the adsorption of H* species. The photo-assisted electrocatalytic activity for HER is significantly enhanced attributed to the strong light absorption capacity of InP, superior energy level configuration of In2O3 and InP, and excellent transient light response of In2O3@InP. Furthermore, the electrode has favorable stability and durability, and the morphology and surface chemical state have no essential changes after the photo-assisted HER stability test.

Porous rod-like structured ternary nitride heterocatalyst Co3Mo3N/Ni3Mo3N for efficient and stable hydrogen evolution reaction

Heterostructure electrocatalysts have garnered widespread attention for effectively enhancing electrocatalytic activity. However, less attention has been paid to ternary nitride heterostructure catalysts for the hydrogen evolution reaction (HER), and their synthesis remains challenging. In this study, a Co3Mo3N/Ni3Mo3N heterostructure catalyst on nickel foam (NF) is designed and prepared via high-temperature nitridation of the heterostructured precursor. The resulting 1D/3D hierarchical structure electrode, featuring rich heterointerfaces, provides abundant active sites, enhancing mass transport and charge transfer. Experimental results reveal strong electronic interactions at the heterointerface, while density functional theory (DFT) calculations establish that Co3Mo3N/Ni3Mo3N possesses a lower water dissociation energy barrier and optimized hydrogen adsorption energy. Consequently, it demonstrates excellent HER performance, exhibiting low overpotentials of 36 mV in alkaline and 58 mV in neutral media at 10 mA cm−2. This study presents an innovative approach to designing ternary nitride heterostructure catalysts with enhanced HER activity, applicable to other heterostructure catalysts.

Catalytic enhancement of graphene oxide by trace molybdenum oxide nanoparticles doping: Optimized electrocatalyst for green hydrogen production

Hydrogen is a clean and renewable energy source that is often regarded as a powerful alternative to traditional fossil fuels. The hydrogen evolution reaction (HER), and oxygen evolution reaction (OER) are the critical stage in this technique, and an effective catalyst must be used to limit its significant overpotential. This report delves into the evaluation of MoO3/rGO-1000 as a cutting-edge electrocatalyst for green hydrogen production. The MoO3/rGO-1000 demonstrated exceptional HER stability and activity for 14 h, exhibiting an overpotential of 35 mV at a current density of 10 mAcm−2. Furthermore, the MoO3/rGO-1000, showed excellent OER activity having a lower overpotential of 213 mV at 10 mAcm−2. The enhanced results may be due to the synergistic effects, and by its inherent metallic conductivity and capacity to adsorb oxygen-containing molecules with high efficiency, MoO3 offers an abundance of active sites for water oxidation throughout the OER process. In the interim, rGO functions as a highly effective electron conductor, improving overall electrocatalytic activity by facilitating charge transfer. Thus, this study concludes that the introduction of MoO3 into graphene oxide significantly enhances the catalytic activities for hydrogen production.

Stable hydrogen evolution reaction at high current densities via designing the Ni single atoms and Ru nanoparticles linked by carbon bridges

Continuous and effective hydrogen evolution under high current densities remains a challenge for water electrolysis owing to the rapid performance degradation under continuous large-current operation. In this study, theoretical calculations, operando Raman spectroscopy, and CO stripping experiments confirm that Ru nanocrystals have a high resistance against deactivation because of the synergistic adsorption of OH intermediates (OHad) on the Ru and single atoms. Based on this conceptual model, we design the Ni single atoms modifying ultra-small Ru nanoparticle with defect carbon bridging structure (UP-RuNiSAs/C) via a unique unipolar pulse electrodeposition (UPED) strategy. As a result, the UP-RuNiSAs/C is found capable of running steadily for 100 h at 3 A cm−2, and shows a low overpotential of 9 mV at a current density of 10 mA cm−2 under alkaline conditions. Moreover, the UP-RuNiSAs/C allows an anion exchange membrane (AEM) electrolyzer to operate stably at 1.95 Vcell for 250 h at 1 A cm−2.

Highly efficient Ni3Se2@sintering porous Ni catalytic electrode for durable hydrogen evolution reaction

The development of cheap, efficient, and long-term stable hydrogen evolution reaction (HER) electrocatalysts is indispensable but still challenging for large-scale industrialized water electrolysis. Recently, many studies have shown that in-situ selenization of metal matrixes is expected to improve the catalytic activity of the metal-based electrodes. In the present work, optimal nickel matrix with controlled polygonal morphology and pore size was obtained by adjusting the sintering process. A highly efficient Ni3Se2@sintered Ni electrode was acquired by in-situ growing nano-Ni3Se2 on sintered Ni matrix using one-step hydrothermal selenization. The metallurgical bonding between Ni particles accelerates electron transfer, and nano-Ni3Se2 provides more active sites. As a consequence, the prepared Ni3Se2@Ni500 electrode can operate stably at current density of 200 mA cm−2 over 260 h. The excellent hydrogen catalytic performance and long-term stability make such electrode promising in the hydrogen evolution reaction.

Boronization to construct a partial CoP amorphous structure for efficient and stable hydrogen evolution reaction

The use of transition metal phosphides for hydrogen evolution reaction has been continuously reported in recent years, but their excessive H* adsorption is detrimental to H2 desorption, as well as their limited specific surface area restricts the exposure of their active sites. Herein, we synthesized CoP by a molten salt method and gas phosphorylation and obtained the target catalyst B-CoP by further treating it with NaBH4 solution. Under the action of NaBH4, a large number of oxide impurities on the surface of the catalyst precursor reacted, generating a large number of oxygen vacancies and partially transforming the CoP of the crystalline-phase structure into an amorphous phase, which resulted in a large number of pore structures and a substantial increase in the specific surface area of the generated B-CoP catalyst. The special nanostructure allows the catalyst to increase the contact area with the electrolyte and accelerates the desorption of gas bubbles, which results in the catalyst exhibiting such a superior catalytic activity, with overpotentials of 104, 156, and 188 mV at 100, 500, and 1000 mA cm−2 current densities, respectively, and can be operated stably at 100 mA cm−2 current density for 100 hours. This work provides new ideas for efficient catalysts for hydrogen evolution reaction from phosphides.

One-Step Synthesis and Operando Electrochemical Impedance Spectroscopic Characterization of Heterostructured MoP-Mo2N Electrocatalysts for Stable Hydrogen Evolution Reaction.

This study presents a novel synthesis of self-standing MoP and Mo2N heterostructured electrocatalysts with enhanced stability and catalytic performance. Facilitated by the controlled phase and interfacial microstructure, the seamless structures of these catalysts minimize internal resistivity and prevent local corrosion, contributing to increased stability. The chemical synthesis proceeds with an etching step to activate the surface, followed by phosphor-nitriding in a chemical vapor deposition chamber to produce MoP-Mo2N@Mo heterostructured electrocatalysts. X-ray diffraction analyses confirmed the presence of MoP, Mo2N, and Mo phases in the electrocatalyst. Morphology studies using scanning electron microscopy characterize the hierarchical growth of structures, indicating successful formation of the heterostructure. X-ray photoelectron spectroscopy (XPS) analyses of the as-synthesized and postcatalytic activity samples reveal the chemical shift in terms of the binding energy (BE) of the Mo 3d XPS peak, especially after catalytic activity. The XPS BE shifts are attributed to changes in the oxidation state, electron transfer, and surface reconstruction during catalysis. Electrochemical evaluation of the catalysts indicates the superior performance of the MoP-Mo2N@Mo heterostructured catalyst in hydrogen evolution reactions (HER), with lower overpotentials and enhanced Tafel slopes. The stability tests reveal changes in double layer capacitance over time, suggesting surface reconstruction and an increased active surface area during catalysis. Operando electrochemical impedance spectroscopy (EIS) further elucidates the dynamic changes in resistance and charge transfer during HER. Overall, a comprehensive understanding of the synthesis, characterization, and electrochemical behavior of the developed MoP-Mo2N@Mo heterostructured electrocatalyst, as presented in this work, highlights its potential utilization in sustainable energy applications.