The growing global demand for clean and sustainable energy has positioned multi-principal refractory high-entropy alloys (MRHEAs) as promising candidates for solid state hydrogen storage owing to their excellent thermal and structural stability, which is crucial for efficient hydrogen absorption-desorption cycling. However, the vast compositional space and complex structure–property relationships of MRHEAs present major design and optimization challenges. This study introduces a CALPHAD (CALculation of PHAse Diagrams)-guided computational framework for the composition–process–property design of Nb–Mo-based MRHEAs, integrating first-principles calculations and thermo-physical modelling to enable high-throughput alloy screening and microstructural prediction. The CALPHAD approach facilitates systematic exploration and prediction of phase equilibria and thermodynamic properties in multi-component systems, providing critical insight into the mechanisms governing hydrogen absorption, diffusion, and desorption. These insights support the evaluation of reversibility, cycling stability, and safety performance in emerging MRHEAs. The review highlights the complementary strengths and limitations of computational approaches while identifying key research gaps in experimental validation, data standardization, and process optimization. Finally, it underscores the importance of integrating CALPHAD with machine learning (ML) and additive manufacturing (AM) to accelerate the rational, data-driven design of next-generation MRHEAs for advanced hydrogen storage applications.
{"title":"Refractory high-entropy alloys for solid-state hydrogen storage: A computational design review","authors":"Abidemi Adeyoye , Patricia Popoola , Olawale Popoola , Samson Adeosun , Modupeola Dada","doi":"10.1016/j.ijhydene.2025.153291","DOIUrl":"10.1016/j.ijhydene.2025.153291","url":null,"abstract":"<div><div>The growing global demand for clean and sustainable energy has positioned multi-principal refractory high-entropy alloys (MRHEAs) as promising candidates for solid state hydrogen storage owing to their excellent thermal and structural stability, which is crucial for efficient hydrogen absorption-desorption cycling. However, the vast compositional space and complex structure–property relationships of MRHEAs present major design and optimization challenges. This study introduces a CALPHAD (CALculation of PHAse Diagrams)-guided computational framework for the composition–process–property design of Nb–Mo-based MRHEAs, integrating first-principles calculations and thermo-physical modelling to enable high-throughput alloy screening and microstructural prediction. The CALPHAD approach facilitates systematic exploration and prediction of phase equilibria and thermodynamic properties in multi-component systems, providing critical insight into the mechanisms governing hydrogen absorption, diffusion, and desorption. These insights support the evaluation of reversibility, cycling stability, and safety performance in emerging MRHEAs. The review highlights the complementary strengths and limitations of computational approaches while identifying key research gaps in experimental validation, data standardization, and process optimization. Finally, it underscores the importance of integrating CALPHAD with machine learning (ML) and additive manufacturing (AM) to accelerate the rational, data-driven design of next-generation MRHEAs for advanced hydrogen storage applications.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"205 ","pages":"Article 153291"},"PeriodicalIF":8.3,"publicationDate":"2026-01-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-05DOI: 10.1016/j.ijhydene.2025.153329
Feidie Li , Zhishuncheng Li , Qiangli Lv , Lin Lv , Hua Wang , Tao Zhu , Xing Zhu , Kongzhai Li , Zhishan Li
Urea-assisted overall water splitting has emerged as a cost-efficient and promising technology for hydrogen production, which not only avoids the formation of an explosive H2/O2 gas mixture but also significantly reduces the energy input required for water electrolysis. In this work, a bifunctional CuNNi3-xMnx catalyst self-supported on nickel foam (NF) was synthesized via a facile hydrothermal method followed by annealing, resulting in highly efficient and stable electrocatalysts for both the urea oxidation reaction (UOR) and the hydrogen evolution reaction (HER). Controlled Mn doping allows precise modulation of the electronic structure of CuNNi2.4Mn0.6 at the Ni active sites, simultaneously enhancing the adsorption/desorption kinetics of hydrogen intermediates (H∗) and facilitating C–N bond cleavage in urea. The optimized CuNNi2.4Mn0.6 catalyst requires only 1.336 V for UOR and 44 mV for HER to achieve a current density of 10 mA cm−2, demonstrating remarkable bifunctional activity. Moreover, when employed as both anode and cathode in a urea-assisted overall water splitting system, the catalyst enables a cell voltage of merely 1.526 V at 10 mA cm−2, significantly lower than that required for conventional water electrolysis (1.695 V vs. RHE). The system also exhibits excellent durability, maintaining stable performance for over 30 h at 10 mA cm−2 without significant activity loss. This work provides a foundation for the further exploration of transition metal-based bifunctional electrocatalysts, paving the way for energy-efficient hydrogen production and simultaneous treatment of urea-rich wastewater.
尿素辅助整体水分解已经成为一种具有成本效益和前景的制氢技术，它不仅避免了爆炸性H2/O2气体混合物的形成，而且大大减少了水电解所需的能量输入。本文采用水热法和退火法制备了一种自负载于泡沫镍（NF）上的双功能CuNNi3-xMnx催化剂，制备了高效稳定的尿素氧化反应（UOR）和析氢反应（HER）电催化剂。控制Mn掺杂可以精确调节CuNNi2.4Mn0.6在Ni活性位点的电子结构，同时增强氢中间体（H *）的吸附/解吸动力学，促进尿素中C-N键的裂解。优化后的CuNNi2.4Mn0.6催化剂只需要1.336 V的UOR和44 mV的HER就能达到10 mA cm−2的电流密度，表现出显著的双功能活性。此外，当在尿素辅助的整体水分解系统中作为阳极和阴极时，该催化剂在10 mA cm - 2时的电池电压仅为1.526 V，显著低于传统电解水所需的电压（1.695 V vs. RHE）。该系统还具有优异的耐用性，在10 mA cm - 2下保持30小时以上的稳定性能，没有明显的活性损失。本研究为进一步探索过渡金属基双功能电催化剂奠定了基础，为高效节能制氢和富尿素废水的同步处理铺平了道路。
{"title":"Mn-doped CuNNi3 antiperovskite for high efficient urea assisted overall water splitting","authors":"Feidie Li , Zhishuncheng Li , Qiangli Lv , Lin Lv , Hua Wang , Tao Zhu , Xing Zhu , Kongzhai Li , Zhishan Li","doi":"10.1016/j.ijhydene.2025.153329","DOIUrl":"10.1016/j.ijhydene.2025.153329","url":null,"abstract":"<div><div>Urea-assisted overall water splitting has emerged as a cost-efficient and promising technology for hydrogen production, which not only avoids the formation of an explosive H<sub>2</sub>/O<sub>2</sub> gas mixture but also significantly reduces the energy input required for water electrolysis. In this work, a bifunctional CuNNi<sub>3-x</sub>Mn<sub>x</sub> catalyst self-supported on nickel foam (NF) was synthesized via a facile hydrothermal method followed by annealing, resulting in highly efficient and stable electrocatalysts for both the urea oxidation reaction (UOR) and the hydrogen evolution reaction (HER). Controlled Mn doping allows precise modulation of the electronic structure of CuNNi<sub>2.4</sub>Mn<sub>0.6</sub> at the Ni active sites, simultaneously enhancing the adsorption/desorption kinetics of hydrogen intermediates (H∗) and facilitating C–N bond cleavage in urea. The optimized CuNNi<sub>2.4</sub>Mn<sub>0.6</sub> catalyst requires only 1.336 V for UOR and 44 mV for HER to achieve a current density of 10 mA cm<sup>−2</sup>, demonstrating remarkable bifunctional activity. Moreover, when employed as both anode and cathode in a urea-assisted overall water splitting system, the catalyst enables a cell voltage of merely 1.526 V at 10 mA cm<sup>−2</sup>, significantly lower than that required for conventional water electrolysis (1.695 V vs. RHE). The system also exhibits excellent durability, maintaining stable performance for over 30 h at 10 mA cm<sup>−2</sup> without significant activity loss. This work provides a foundation for the further exploration of transition metal-based bifunctional electrocatalysts, paving the way for energy-efficient hydrogen production and simultaneous treatment of urea-rich wastewater.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"205 ","pages":"Article 153329"},"PeriodicalIF":8.3,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-05DOI: 10.1016/j.ijhydene.2026.153373
Wojciech Tutak, Arkadiusz Jamrozik, Karol Grab-Rogaliński, Michał Pyrc, Michał Gruca
The study presents the results of an evaluation of the combustion process in a compression ignition engine fuelled with diesel, ammonia, and hydrogen, which were fed to the intake manifold in the gas phase. The minimization of fossil fuel use aligns with the trend of decarbonizing internal combustion engines. Ammonia significantly reduces soot emissions in a compression ignition engine; however, due to its low laminar combustion speed, it substantially slows down the combustion process. This drawback can be mitigated by the addition of hydrogen. The study examines the impact of hydrogen addition to ammonia on combustion characteristics and stability. The experiments were conducted on an engine fuelled with diesel and 40 % ammonia by energy fraction. In subsequent stages, ammonia was progressively replaced with hydrogen, up to 28 % by energy fraction. The addition of H2 accelerated the heat release process and reduced ignition delay by 3.5 deg. With the increase in the hydrogen energy fraction, increase in cycle-to-cycle variation and dispersion of combustion phases was observed. At a 28 % hydrogen energy fraction, the coefficient of variation of indicated mean effective pressure (COVIMEP) increased beyond 5 %. Ammonia co-combusted with diesel and hydrogen reduced engine thermal efficiency by 6 % compared to the reference case, mainly due to an increase in the uniqueness of the end of combustion and energy losses to the combustion chamber wall. Ammonia co-combusted with diesel reduced the specific soot emissions from 4.48 to 0.28 g/kWh.
{"title":"Effect of ammonia-hydrogen fuel ratio on combustion stability, performance and emissions of an industrial diesel engine","authors":"Wojciech Tutak, Arkadiusz Jamrozik, Karol Grab-Rogaliński, Michał Pyrc, Michał Gruca","doi":"10.1016/j.ijhydene.2026.153373","DOIUrl":"10.1016/j.ijhydene.2026.153373","url":null,"abstract":"<div><div>The study presents the results of an evaluation of the combustion process in a compression ignition engine fuelled with diesel, ammonia, and hydrogen, which were fed to the intake manifold in the gas phase. The minimization of fossil fuel use aligns with the trend of decarbonizing internal combustion engines. Ammonia significantly reduces soot emissions in a compression ignition engine; however, due to its low laminar combustion speed, it substantially slows down the combustion process. This drawback can be mitigated by the addition of hydrogen. The study examines the impact of hydrogen addition to ammonia on combustion characteristics and stability. The experiments were conducted on an engine fuelled with diesel and 40 % ammonia by energy fraction. In subsequent stages, ammonia was progressively replaced with hydrogen, up to 28 % by energy fraction. The addition of H<sub>2</sub> accelerated the heat release process and reduced ignition delay by 3.5 deg. With the increase in the hydrogen energy fraction, increase in cycle-to-cycle variation and dispersion of combustion phases was observed. At a 28 % hydrogen energy fraction, the coefficient of variation of indicated mean effective pressure (COV<sub>IMEP</sub>) increased beyond 5 %. Ammonia co-combusted with diesel and hydrogen reduced engine thermal efficiency by 6 % compared to the reference case, mainly due to an increase in the uniqueness of the end of combustion and energy losses to the combustion chamber wall. Ammonia co-combusted with diesel reduced the specific soot emissions from 4.48 to 0.28 g/kWh.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"205 ","pages":"Article 153373"},"PeriodicalIF":8.3,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-05DOI: 10.1016/j.ijhydene.2025.153311
Dheeraj Kumar , Mohit Khosya , Neeraj Khare
In this paper, we demonstrate a novel strategy of combining the piezoelectric with plasmonic effect to enhance the photoelectrochemical (PEC) water splitting. Silver (Ag) nanoparticles loaded binary g-C3N4/NaNbO3 (Ag/g-CN/NBO) photoanode has been fabricated, in which coupling of g-CN with NBO provided the piezo-photo effect, whereas decorating with Ag nanoparticles provided the plasmonic effect. The observed current density of the binary g-CN/NBO photoanode is 8.22 mA/cm2 at 1.4 V vs. RHE, which is ∼2.6 times higher than the bare NBO photoanode. This enhancement is due to the utilization of a wider range of solar spectrum, formation of heterojunction, and the piezoelectric effect that facilitates efficient separation of photogenerated charge carriers. On decorating with Ag nanoparticles, the current density of ternary Ag/g-CN/NBO photoanode further enhances to 10.91 mA/cm2 at 1.4 V vs. RHE under ultrasonic vibration + light, which is ∼3.5 times higher than bare NBO photoanode under ultrasonic vibration (3.08 mA/cm2 at 1.4 V vs. RHE). This significant enhancement is attributed to the combined results of the plasmonic effect from Ag nanoparticles and piezoelectric-induced charge separation, which collectively contribute to enhanced overall PEC efficiency. This approach offers a promising method and concept for developing feasible and high-performance ternary photoelectrodes for hydrogen production using a combined piezoelectric and plasmonic-assisted solar light-driven PEC water splitting application.
在本文中，我们展示了一种结合压电和等离子体效应来增强光电化学（PEC）水分解的新策略。制备了银（Ag）纳米粒子负载二元g-C3N4/NaNbO3 （Ag/g-CN/NBO）光阳极，其中g-CN与NBO耦合产生压电光效应，Ag纳米粒子修饰产生等离子体效应。在1.4 V vs. RHE下，g-CN/NBO二元光阳极的电流密度为8.22 mA/cm2，是裸NBO光阳极的约2.6倍。这种增强是由于利用了更广泛的太阳光谱，形成了异质结，以及压电效应，促进了光生电荷载流子的有效分离。Ag纳米粒子修饰后，在超声振动+光下，Ag/g-CN/NBO三元光阳极的电流密度进一步提高到10.91 mA/cm2，比NBO光阳极在超声振动+光下的电流密度（3.08 mA/cm2, 1.4 V vs. RHE）高约3.5倍。这种显著的增强归因于银纳米粒子的等离子体效应和压电诱导的电荷分离的综合结果，它们共同促进了整体PEC效率的提高。该方法为开发可行的高性能三元光电极提供了一种有前途的方法和概念，用于利用压电和等离子体辅助的太阳能光驱动PEC水分解应用。
{"title":"Coupling of piezo-plasmonic-photo effect in ternary Ag/g-C3N4/NaNbO3 nanocomposite for enhanced photoelectrochemical water splitting","authors":"Dheeraj Kumar , Mohit Khosya , Neeraj Khare","doi":"10.1016/j.ijhydene.2025.153311","DOIUrl":"10.1016/j.ijhydene.2025.153311","url":null,"abstract":"<div><div>In this paper, we demonstrate a novel strategy of combining the piezoelectric with plasmonic effect to enhance the photoelectrochemical (PEC) water splitting. Silver (Ag) nanoparticles loaded binary g-C<sub>3</sub>N<sub>4</sub>/NaNbO<sub>3</sub> (Ag/g-CN/NBO) photoanode has been fabricated, in which coupling of g-CN with NBO provided the piezo-photo effect, whereas decorating with Ag nanoparticles provided the plasmonic effect. The observed current density of the binary g-CN/NBO photoanode is 8.22 mA/cm<sup>2</sup> at 1.4 V <em>vs</em>. RHE, which is ∼2.6 times higher than the bare NBO photoanode. This enhancement is due to the utilization of a wider range of solar spectrum, formation of heterojunction, and the piezoelectric effect that facilitates efficient separation of photogenerated charge carriers. On decorating with Ag nanoparticles, the current density of ternary Ag/g-CN/NBO photoanode further enhances to 10.91 mA/cm<sup>2</sup> at 1.4 V <em>vs.</em> RHE under ultrasonic vibration + light, which is ∼3.5 times higher than bare NBO photoanode under ultrasonic vibration (3.08 mA/cm<sup>2</sup> at 1.4 V <em>vs.</em> RHE). This significant enhancement is attributed to the combined results of the plasmonic effect from Ag nanoparticles and piezoelectric-induced charge separation, which collectively contribute to enhanced overall PEC efficiency. This approach offers a promising method and concept for developing feasible and high-performance ternary photoelectrodes for hydrogen production using a combined piezoelectric and plasmonic-assisted solar light-driven PEC water splitting application.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"205 ","pages":"Article 153311"},"PeriodicalIF":8.3,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-05DOI: 10.1016/j.ijhydene.2026.153375
Theyab R. Alsenani , Sulman Shahzad , Heybet Kilic
Weak AC grids with high inverter-based renewable penetration are prone to sub-synchronous oscillations (SSOs), especially under low short-circuit ratio (SCR) conditions. This paper proposes a hybrid energy storage system (HESS) combining fast-response electric double-layer capacitors (EDLCs) with slower hydrogen storage to enhance damping across multiple frequency ranges. The methodology integrates detailed dynamic modeling of PEM electrolyzer and fuel-cell behavior, inverter–grid interactions, and a coordinated fast–slow control strategy that allocates rapid transient support to the EDLC and long-term balancing to the hydrogen subsystem. A small-signal linearized model is used to identify the PLL–CCL interaction responsible for SSO formation, and the proposed control design is evaluated in MATLAB/Simulink using a fixed-step solver suitable for high-frequency dynamics. Simulation studies under three disturbance scenarios—solar irradiance steps, transmission-line disconnection (SCR reduction), and sudden load variation—show that the HESS reduces oscillation amplitude by approximately 60–70 % and shortens settling time by more than half compared with the baseline system. The results demonstrate that the proposed hybrid architecture provides robust and practical damping support for weak-grid environments.
{"title":"Hybrid hydrogen systems for mitigating sub synchronous oscillations in weak power grids","authors":"Theyab R. Alsenani , Sulman Shahzad , Heybet Kilic","doi":"10.1016/j.ijhydene.2026.153375","DOIUrl":"10.1016/j.ijhydene.2026.153375","url":null,"abstract":"<div><div>Weak AC grids with high inverter-based renewable penetration are prone to sub-synchronous oscillations (SSOs), especially under low short-circuit ratio (SCR) conditions. This paper proposes a hybrid energy storage system (HESS) combining fast-response electric double-layer capacitors (EDLCs) with slower hydrogen storage to enhance damping across multiple frequency ranges. The methodology integrates detailed dynamic modeling of PEM electrolyzer and fuel-cell behavior, inverter–grid interactions, and a coordinated fast–slow control strategy that allocates rapid transient support to the EDLC and long-term balancing to the hydrogen subsystem. A small-signal linearized model is used to identify the PLL–CCL interaction responsible for SSO formation, and the proposed control design is evaluated in MATLAB/Simulink using a fixed-step solver suitable for high-frequency dynamics. Simulation studies under three disturbance scenarios—solar irradiance steps, transmission-line disconnection (SCR reduction), and sudden load variation—show that the HESS reduces oscillation amplitude by approximately 60–70 % and shortens settling time by more than half compared with the baseline system. The results demonstrate that the proposed hybrid architecture provides robust and practical damping support for weak-grid environments.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"205 ","pages":"Article 153375"},"PeriodicalIF":8.3,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-05DOI: 10.1016/j.ijhydene.2025.153345
ShiLin Lei , Shigang Yang , Yulong Duan , Junhao Dai
In this study, dual-attribute structures are employed to investigate the thermo-wave evolution characteristics of hydrogen-blended methane. Results indicate that dual-attribute structures induce "mountain-shaped" cavities, bidirectional inward flame vortices, and chaotic vortices, while exerting both restraining and exciting effects. The flame velocity exhibits initial peak increase-decay, slow rise, and rapid increase stages. Both the contact velocity and maximum velocity increase with the increase in structure blockage ratio (BR) and hydrogen ratio. Transverse and longitudinal waves cause deformation of flexible structures, where the tilt angle is positively correlated with the initial BR, and actual BR follows a cosine function. Flexible BR exerts a more significant influence on the intensity and growth amplitude of longitudinal waves, whereas the intensity of transverse waves depends on the hydrogen addition ratio. The height of the rigid structure (H) should be sufficiently large, while that of the flexible structure (h) should be minimized in explosion protection environment.
{"title":"Research on deflagration characteristics of hydrogen-blended methane premixed gas under dual-attribute structural protection layouts","authors":"ShiLin Lei , Shigang Yang , Yulong Duan , Junhao Dai","doi":"10.1016/j.ijhydene.2025.153345","DOIUrl":"10.1016/j.ijhydene.2025.153345","url":null,"abstract":"<div><div>In this study, dual-attribute structures are employed to investigate the thermo-wave evolution characteristics of hydrogen-blended methane. Results indicate that dual-attribute structures induce \"mountain-shaped\" cavities, bidirectional inward flame vortices, and chaotic vortices, while exerting both restraining and exciting effects. The flame velocity exhibits initial peak increase-decay, slow rise, and rapid increase stages. Both the contact velocity and maximum velocity increase with the increase in structure blockage ratio (BR) and hydrogen ratio. Transverse and longitudinal waves cause deformation of flexible structures, where the tilt angle is positively correlated with the initial BR, and actual BR follows a cosine function. Flexible BR exerts a more significant influence on the intensity and growth amplitude of longitudinal waves, whereas the intensity of transverse waves depends on the hydrogen addition ratio. The height of the rigid structure (H) should be sufficiently large, while that of the flexible structure (h) should be minimized in explosion protection environment.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"205 ","pages":"Article 153345"},"PeriodicalIF":8.3,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923176","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Developing efficient, non-noble electrocatalysts to overcome the sluggish oxygen evolution reaction (OER) is critical for large-scale hydrogen production. Herein, self-supported hafnium nitride (HfN) thin films have been fabricated on nickel foam (NF) via magnetron sputtering as binder-free OER catalysts. By regulating the substrate temperature to 100 °C, a porous nanocolumnar structure with abundant nitrogen vacancies is achieved, enhancing active site exposure and charge transfer. As a result, the optimized HfN/NF electrodes deliver exceptional alkaline OER performance, requiring only 302 and 316 mV overpotentials to reach 25 and 50 mA cm−2, along with a low Tafel slope of 46.3 mV dec−1. It also demonstrates remarkable stability for 48 h chronopotentiometry tests, which is attributed to the in-situ formed surface oxide layer. This work offers a scalable and binder-free strategy for constructing high-performance transition metal nitride electrocatalysts.
开发高效的非贵金属电催化剂来克服缓慢的析氧反应（OER）是大规模制氢的关键。本文以无粘结剂OER为催化剂，通过磁控溅射在泡沫镍（NF）表面制备了自支撑型氮化铪（HfN）薄膜。通过调节衬底温度至100°C，获得了具有丰富氮空位的多孔纳米柱结构，增强了活性位点暴露和电荷转移。因此，优化后的HfN/NF电极具有优异的碱性OER性能，仅需302和316 mV过电位即可达到25和50 mA cm - 2，同时Tafel斜率低至46.3 mV dec - 1。它还表现出48小时计时电位测定测试的显著稳定性，这是由于原位形成的表面氧化层。这项工作为构建高性能过渡金属氮化物电催化剂提供了一种可扩展和无粘结剂的策略。
{"title":"Self-supported hafnium nitride thin film electrocatalysts for efficient oxygen evolution reaction","authors":"Xutao Yan , Binbin Wei , Dongfang Zhang , Haojun Zeng , Quanxing Guo , Qiaoyan Chen , Jingang Wu , Xun Xu , Ye Zeng , Hanfeng Liang , Zhengbing Qi","doi":"10.1016/j.ijhydene.2025.153215","DOIUrl":"10.1016/j.ijhydene.2025.153215","url":null,"abstract":"<div><div>Developing efficient, non-noble electrocatalysts to overcome the sluggish oxygen evolution reaction (OER) is critical for large-scale hydrogen production. Herein, self-supported hafnium nitride (HfN) thin films have been fabricated on nickel foam (NF) via magnetron sputtering as binder-free OER catalysts. By regulating the substrate temperature to 100 °C, a porous nanocolumnar structure with abundant nitrogen vacancies is achieved, enhancing active site exposure and charge transfer. As a result, the optimized HfN/NF electrodes deliver exceptional alkaline OER performance, requiring only 302 and 316 mV overpotentials to reach 25 and 50 mA cm<sup>−2</sup>, along with a low Tafel slope of 46.3 mV dec<sup>−1</sup>. It also demonstrates remarkable stability for 48 h chronopotentiometry tests, which is attributed to the in-situ formed surface oxide layer. This work offers a scalable and binder-free strategy for constructing high-performance transition metal nitride electrocatalysts.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"205 ","pages":"Article 153215"},"PeriodicalIF":8.3,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923069","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-05DOI: 10.1016/j.ijhydene.2025.153197
Gustavo Chacón-Rosales , Rafael C. Lima , Fabiano S. Rodembusch , Allan de Moraes Lisbôa , Claudio Radtke , Adriano F. Feil , Christian W. Lopes , Debora Meira , Sibele B.C. Pergher , Jairton Dupont
This study presents a fast and eco-friendly strategy to develop a photocatalytic system based on potassium hexaniobate K4Nb6O17·xH2O (KNbO) modified with sub-nanometric copper clusters (SNCu) produced via sputtering. Despite the low metal loading (0.6 wt%), the material shows excellent hydrogen production from methanol photoreforming (MPR) and water splitting reaction (WSR) under simulated sunlight. Encapsulation with the ionic liquid [BMIm][NTf2] (IL@SNCu@KNbO) further enhances activity and stability, reaching 170 μmol H2 (4000 μmol g−1 h−1; AQY = 26.8 %) and outperforming SNCu@KNbO (160 μmol) and pristine KNbO (2.9 μmol). Structural and spectroscopic analyses confirm homogeneous SNCu dispersion and strong metal-semiconductor interactions. The IL plays a key role in improving interfacial charge dynamics, forming a polar nanolayer that increases the band gap (from 3.64 to 3.81 eV), broadens the valence band, and suppresses photoluminescence by ≈ 80 %, evidencing reduced recombination. XPS and solid-state NMR demonstrate that the IL remains chemically stable, protecting SNCu sites against aggregation and photo-corrosion. Replicate experiments show that while the IL significantly enhances pristine KNbO, its effect is partially masked in SNCu@KNbO due to the strong electron-sink behavior of the ultra-small copper clusters. Stability tests reveal consistent performance over four cycles, with moderate activity loss after the sixth cycle associated with 0.84 ppm Cu in solution and TGA indications of partial IL restructuring. Overall, the catalyst remains functional and durable by four cycles, demonstrating the potential of combining sputtered SNCu clusters with IL encapsulation as a sustainable route for hydrogen generation using low metal loadings and environmentally friendly processing.
{"title":"Eco-designed ultra-small copper/ionic liquid interfaces on layered niobates for hydrogen production via water-splitting and methanol photoreforming","authors":"Gustavo Chacón-Rosales , Rafael C. Lima , Fabiano S. Rodembusch , Allan de Moraes Lisbôa , Claudio Radtke , Adriano F. Feil , Christian W. Lopes , Debora Meira , Sibele B.C. Pergher , Jairton Dupont","doi":"10.1016/j.ijhydene.2025.153197","DOIUrl":"10.1016/j.ijhydene.2025.153197","url":null,"abstract":"<div><div>This study presents a fast and eco-friendly strategy to develop a photocatalytic system based on potassium hexaniobate K<sub>4</sub>Nb<sub>6</sub>O<sub>17</sub>·xH<sub>2</sub>O (<strong>KNbO</strong>) modified with sub-nanometric copper clusters (SNCu) produced via sputtering. Despite the low metal loading (0.6 wt%), the material shows excellent hydrogen production from methanol photoreforming (MPR) and water splitting reaction (WSR) under simulated sunlight. Encapsulation with the ionic liquid [BMIm][NTf<sub>2</sub>] (<strong>IL@SNCu@KNbO</strong>) further enhances activity and stability, reaching 170 μmol H<sub>2</sub> (4000 μmol g<sup>−1</sup> h<sup>−1</sup>; AQY = 26.8 %) and outperforming <strong>SNCu@KNbO</strong> (160 μmol) and pristine <strong>KNbO</strong> (2.9 μmol). Structural and spectroscopic analyses confirm homogeneous SNCu dispersion and strong metal-semiconductor interactions. The IL plays a key role in improving interfacial charge dynamics, forming a polar nanolayer that increases the band gap (from 3.64 to 3.81 eV), broadens the valence band, and suppresses photoluminescence by ≈ 80 %, evidencing reduced recombination. XPS and solid-state NMR demonstrate that the IL remains chemically stable, protecting SNCu sites against aggregation and photo-corrosion. Replicate experiments show that while the IL significantly enhances pristine <strong>KNbO</strong>, its effect is partially masked in <strong>SNCu@KNbO</strong> due to the strong electron-sink behavior of the ultra-small copper clusters. Stability tests reveal consistent performance over four cycles, with moderate activity loss after the sixth cycle associated with 0.84 ppm Cu in solution and TGA indications of partial IL restructuring. Overall, the catalyst remains functional and durable by four cycles, demonstrating the potential of combining sputtered SNCu clusters with IL encapsulation as a sustainable route for hydrogen generation using low metal loadings and environmentally friendly processing.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"205 ","pages":"Article 153197"},"PeriodicalIF":8.3,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-05DOI: 10.1016/j.ijhydene.2025.153308
Naima Faiz , Sawaira Moeen , Muhammad Imran , Anwar Ul-Hamid , Muhammad Mansha , Muhammad Ikram
Energy scarcity and environmental protection are dual challenges for current global communities. Scalable, non-toxic and earth abundant tin ferrite (SnFe2O4) serves as an electrode material and is potential candidate for energy conversions (anodic water splitting) and storage (supercapacitor), however, constraint by electron transport limitations and inefficient utilization of active material. Here we synthesize manganese (Mn) and activated carbon (AC) integrated SnFe2O4 via co-precipitation approach. Electrochemical measurement reveals that the doped SnFe2O4 exhibit abundant active sites, refined electronic structure, augmented electronic properties, and favorable adsorption energies for catalytic intermediates. As an electrode material for oxygen evolution reaction (OER), highly doped optimum sample (5 wt % of Mn) shows low overpotential of 217 mV at 10 mA cm−2 and Tafel slope of 47 mV dec−1. This optimum designed electrode presents the specific capacitance of 735.4 Fg-1 at 1.2 Ag-1. These finding yield an efficient bifunctional electrocatalyst for OER and supercapacitor applications.
{"title":"Multifunctional manganese and activated carbon supported SnFe2O4 nanocubes for water oxidation and electrochemical storage","authors":"Naima Faiz , Sawaira Moeen , Muhammad Imran , Anwar Ul-Hamid , Muhammad Mansha , Muhammad Ikram","doi":"10.1016/j.ijhydene.2025.153308","DOIUrl":"10.1016/j.ijhydene.2025.153308","url":null,"abstract":"<div><div>Energy scarcity and environmental protection are dual challenges for current global communities. Scalable, non-toxic and earth abundant tin ferrite (SnFe<sub>2</sub>O<sub>4</sub>) serves as an electrode material and is potential candidate for energy conversions (anodic water splitting) and storage (supercapacitor), however, constraint by electron transport limitations and inefficient utilization of active material. Here we synthesize manganese (Mn) and activated carbon (AC) integrated SnFe<sub>2</sub>O<sub>4</sub> via co-precipitation approach. Electrochemical measurement reveals that the doped SnFe<sub>2</sub>O<sub>4</sub> exhibit abundant active sites, refined electronic structure, augmented electronic properties, and favorable adsorption energies for catalytic intermediates. As an electrode material for oxygen evolution reaction (OER), highly doped optimum sample (5 wt % of Mn) shows low overpotential of 217 mV at 10 mA cm<sup>−2</sup> and Tafel slope of 47 mV dec<sup>−1</sup>. This optimum designed electrode presents the specific capacitance of 735.4 Fg<sup>-1</sup> at 1.2 Ag<sup>-1</sup>. These finding yield an efficient bifunctional electrocatalyst for OER and supercapacitor applications.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"205 ","pages":"Article 153308"},"PeriodicalIF":8.3,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-05DOI: 10.1016/j.ijhydene.2025.153249
Rabia Nawaz , Sajid Mahmood , Anum Bilal , Shahid Iqbal , Ali Hussain , Muhammad Sajjad , Syed Kashif Ali , Farruh Atamurotov , Doniyor Jumanazarov , Salah Knani , Ali Bahadur , Abd-ElAziem Farouk , Nouf M. Alyami
There are still not many meaningful alternatives to converting too-nitrogenated water into ammonia. This is mostly because it requires highly active and long-lasting catalysts. In this paper, we obtained a catalyst that meets these requirements by producing cobalt phosphide nanoparticles in a phosphorus-doped carbon matrix via an easy pyrolysis process. The composite was deposited onto carbon paper for the composite to better operate as an electrochemical material. A thorough structural and surface analysis confirmed that the CoP particles were embedded in the carbon matrix. This created a lot of reactive sites that made it easy for charges to move quickly through the material, which in turn created a lot of active sites that made it easy for charges to move quickly through the catalyst. As a result, the material produced ammonia at a rate of 0.5 mmol h-1 mgcat−1 and had a Faradaic efficiency of 86.18 % at −1.6 V vs. SCE. Computational research further indicated that the strong interaction between CoP and the doped carbon matrix makes it easier for important intermediates to stick to the surface, lowers the energy barrier for the rate-limiting phase, and effectively stops the competing hydrogen evolution pathway. These results suggest that the CoP-PC system is a strong and useful option for getting rid of nitrate pollution and making ammonia at the same time.
{"title":"Boosting nitrate-to-ammonia electrocatalysis through CoP-embedded phosphide doped carbon: Unrivaled efficiency and durability","authors":"Rabia Nawaz , Sajid Mahmood , Anum Bilal , Shahid Iqbal , Ali Hussain , Muhammad Sajjad , Syed Kashif Ali , Farruh Atamurotov , Doniyor Jumanazarov , Salah Knani , Ali Bahadur , Abd-ElAziem Farouk , Nouf M. Alyami","doi":"10.1016/j.ijhydene.2025.153249","DOIUrl":"10.1016/j.ijhydene.2025.153249","url":null,"abstract":"<div><div>There are still not many meaningful alternatives to converting too-nitrogenated water into ammonia. This is mostly because it requires highly active and long-lasting catalysts. In this paper, we obtained a catalyst that meets these requirements by producing cobalt phosphide nanoparticles in a phosphorus-doped carbon matrix via an easy pyrolysis process. The composite was deposited onto carbon paper for the composite to better operate as an electrochemical material. A thorough structural and surface analysis confirmed that the CoP particles were embedded in the carbon matrix. This created a lot of reactive sites that made it easy for charges to move quickly through the material, which in turn created a lot of active sites that made it easy for charges to move quickly through the catalyst. As a result, the material produced ammonia at a rate of 0.5 mmol h-1 mg<sub>cat</sub><sup>−1</sup> and had a Faradaic efficiency of 86.18 % at −1.6 V vs. SCE. Computational research further indicated that the strong interaction between CoP and the doped carbon matrix makes it easier for important intermediates to stick to the surface, lowers the energy barrier for the rate-limiting phase, and effectively stops the competing hydrogen evolution pathway. These results suggest that the CoP-PC system is a strong and useful option for getting rid of nitrate pollution and making ammonia at the same time.</div></div>","PeriodicalId":337,"journal":{"name":"International Journal of Hydrogen Energy","volume":"205 ","pages":"Article 153249"},"PeriodicalIF":8.3,"publicationDate":"2026-01-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145923075","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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