Conversion of metal–organic frameworks (MOFs) into metal-nitrogen-doped carbon (M–N–C) catalysts requires a high-temperature process and longer processing time under a protective atmosphere. This study utilizes a low-energy nanosecond laser processing (LP) technique to convert aqueous synthesized 2D leaf-like Co-MOF (L-Co-MOF) into nanoscale cobalt metal encapsulated within a nitrogen-doped graphitic carbon matrix (Co@N-gC, Co-LP) in a shorter period under air atmosphere. The laser-induced process results in the formation of Co@N-gC with smaller Co particle size, uniform distribution, and better interaction with the carbon support compared to the conventional pyrolysis process (CP). LP catalysts result in enhanced multifunctional electrocatalytic activity over CP (Co-CP) catalysts owing to the tunable metal–support interaction, higher charge transfer, and presence of multiactive sites. Under optimized conditions (laser fluence: 5.76 mJ cm−2 and scan speed: 10 mm s−1), the Co-LP-5 catalyst exhibits better ORR performance, with onset and half-wave potentials of 0.92 and 0.76 V, respectively. Additionally, Co-LP-5 delivers excellent water-splitting performance, with OER and HER overpotentials of 380 and 280 mV, respectively, achieving an overall energy efficiency of 77.85%. Furthermore, Co-LP-5 demonstrates exceptional durability over 48 h of real-time testing, outperforming the Co-CP, and the proposed low-energy LP is viable for fabricating multifunctional catalysts. © 2025 Wiley-VCH GmbH.

In this study, PtCo alloy nanoparticles (NPs) were successfully synthesized and deposited on nitrogen-rich carbon nanosheets derived from Polypyrrole-g-C3N4 using a chemical reduction method. This electrocatalyst not only offers enhanced catalytic efficiency but also significantly improves the stability for the oxygen reduction reaction (ORR) in in acidic medium. In terms of electrocatalytic performance, the PtCo/CN@PPY-g-C3N4 catalyst demonstrated a mass activity of 0.378 mA µgPt−1 at 0.85 V, 0.131 mA µgPt−1 at 0.9 V and a specific activity of 2.900 mA cmPt−2 at 0.85 V, 1.004 mA cmPt−2 at 0.9 V which are respectively 2.3, 2.8 and 10, 12 times higher than those of a commercial 20% Pt/C catalyst (0.166 mA µgPt−1 at 0.85 V, 0.046 mA µgPt−1 at 0.9 V and 0.285 mA cmPt−2 at 0.85 V, 0.079 mA cmPt−2 at 0.9 V). This indicates superior catalytic activity. Furthermore, after 5000 cycles, the PtCo/CN@PPY-g-C3N4 retained approximately 77% at 0.85 V and 83% at 0.9 V of its initial mass activity, with only a 14 mV decrease in the half-wave potential, whereas commercial 20% Pt/C catalyst retained only 40% at0.85 V and 30% at 0.9 V of its initial mass activity. These enhancements can be attributed to the synergistic effects and strong interactions between the Pt–Co alloy nanoparticles and the carbon nitride support. The findings of this study underscore the potential of PtCo/CN@PPY-g-C3N4 as a viable and efficient alternative to traditional catalysts in electrochemical applications. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2024.

The ability to synthesize multi-metal elements into a single-component material at the nanoscale, known as high entropy oxide (HEO) is earning great attention, especially in the field of electrocatalysis. However, the present methods for the synthesis of HEO often involve non-noble, noble, or refractory elements, which require complicated synthesis methods, making the control of shape and size highly challenging. In this regard, a class of six dissimilar elements (Co, Ni, Mn, Mo, V and Zn) with combination of non-noble and refractory elements has been formed a new type of (Co0.5Ni0.5Mn0.5Mo0.5V0.5Zn0.5)O based HEO. The multi-element interaction and carbonization network enhance ion conductivity, boosting specific capacitance to 698.4 F.g⁻¹, far surpassing conventional metal oxides. In addition, the HEO on screen printed electrode exhibited a notable increase in the oxidation peak current for the oxidation of dopamine, which can detect dopamine at nanomolar levels. © 2025 The Authors

Achieving efficient electrocatalysis for sustainably converting energy demands precise tuning of the structure-activity relationship of catalysts. Herein, we introduce a novel strategy for optimizing 2D PdCu bimetallene layers (BMLs) via an electrochemical dealloying (DA) process, modulating the electronic structures via lattice strain distortion. This boosts heterojunction surface activity and accelerates reaction kinetics, establishing DA PdCu BMLs as potential electrocatalyst for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline media. At 10 mA cm−2, the DA PdCu BMLs achieve low overpotentials of 301 (OER) and 221 mV (HER) on a glassy carbon disc electrode. On carbon cloth electrodes in 1 M KOH, the DA PdCu BMLs achieve overpotentials of 177 (OER) and 127 mV (HER), outperforming the untreated PdCu BMLs that achieve 237 and 245 mV, respectively. Stability tests over 10,000 cycles reveal minimal degradation, with only a 3-mV shift in the OER overpotential, unlike the 22 and 54 mV for the PdCu BMLs and Pd/C, respectively. The PdCu and DA PdCu BMLs require 189 and only 161 mV to reach 10 mA cm−2 for the HER, respectively. Theoretical calculations show that electronic modulation alters OER and HER intermediate adsorption on PdCu and DA PdCu BMLs, which is in line with experimental observation. This study underscores the importance of electronic modulation and defect engineering in optimizing catalytic performance and stability for water splitting. © 2025 Elsevier Ltd

Catalyst layer (CL) is the major component of proton exchange membrane fuel cells (PEMFCs) and routinely fabricated by a catalyst ink-based processing method. Such conventional CLs typically confront low activity, unaffordable Pt loading, and severe mass transport issues due to the thick and disordered structure, hampering the widespread commercial application of PEMFCs. Engineering of nanostructured CLs with low/ultralow Pt loading, ordered and/or ultrathin CLs, provides a highly promising pathway for overcoming these limitations. For the practical application of the nanostructured CLs in PEMFCs, this review comprehensively summarizes and comments on the important research and development of nanostructured CLs over recent years, involving ordered electronic conductor-based CLs, ordered ionomer-based CLs, and ultrathin CLs. The reviewed processes include (i) analyzing the motivation and necessity to design and fabricate nanostructured CLs based on the structure and mass transport process of conventional CLs, (ii) scrutinizing structure and composition, preparation methods, advantages, as well as some feasible strategies for the remaining challenges of various nanostructured CLs in detail, (iii) the progress of single cell activity and durability of the nanostructured CLs. Finally, some perspectives on remaining challenges and future development of the nanostructured CLs are presented to guide the exploitation for the next-generation of advanced CLs of PEMFCs. © 2025 Elsevier B.V.

Highly sensitive ammonia (NH3) gas sensors play a critical role in various industries due to their direct implication for health and safety. Nanocomposites have gained massive attention for recent electrochemical gas sensing. In this work, we first propose a Ni-doped MnO2/Ti3C2Tx MXene nanocomposite material for electrochemical NH3 gas sensing at room temperature. Ni-doped MnO2 nanowires were introduced to Ti3C2Tx MXene using a self-assembly technique to develop a high-performance gas sensor. The nanocomposite was characterized using BET, SEM-EDS, XRD, and XPS analyses, which revealed that the Ni-MnO2 nanowires were uniformly distributed on the MXene surface, significantly increasing the surface area. The Ni-MnO2/Ti3C2Tx MXene nanocomposite was immobilized on a screen-printed carbon electrode (SPCE), which is the most appropriate platform for portable and convenient electrochemical sensors, and ionic liquid was used as an electrolyte to achieve high stability. Electrochemical analysis showed that this new NH3 gas sensor had outstanding performance with a higher sensitivity and a lower detection limit of 0.072 µA/ppm and 0.23 ppm, respectively. It also exhibited a fast response time of 45 s at 20 ppm NH3 gas, high repeatability, selectivity, and long-term stability. In addition, the electrochemical NH3 gas nanosensor was successfully demonstrated to monitor food freshness. © 2025 Elsevier B.V.

Ternary nanostructured materials, fabricated by integrating three diverse metals, have been considered as promising cathode catalysts for fuel cells because of their synergetic effects and strain/ligand effects. That can result in effective charge transfer, weakened interactions with oxygenated species, and excellent methanol resistance. Owing to continued improvements in the production of ternary nanostructured materials, it is imperative to focus on recent advancements in this field. The present paper reviews different ternary nanostructures (i.e., support-free structures and supported catalysts), with an emphasis on their preparation methods, compositional and structural characteristics, as well as catalytic performance for oxygen reduction reactions (ORR). Moreover, the latest advances in ternary nanostructured catalysts for ORR at the cathodes of proton exchange membrane fuel cells (PEMFCs) and direct methanol fuel cells (DMFCs) are highlighted. This work provides insights into designing advanced ternary catalysts with an analysis of challenging issues in developing highly efficient and stable nanomaterials for ORR electro-catalysis and suggests some perspectives for alleviating the difficulties toward practical implementation. © 2025 Elsevier B.V.

Two-dimensional (2D) PdCu bimetallene (PdCu) exhibits unique structural and electronic properties, enhancing surface reactivity for crucial electrochemical reactions in energy conversion and storage. The one-pot synthesis, followed by dealloying (DA) to form DA PdCu, further enhances surface reactivity by altering the electronic structure. This process induces geometrical effects, significantly impacting surface strain and influencing selectivity and performance for (oxygen reduction reaction) ORR and (methanol oxidation reaction) MOR in an alkaline medium. The heterogeneous surface of DA PdCu with crystalline and amorphous regions and abundant surface defects, enhances active sites for improved ORR and MOR kinetics. During ORR, the DA PdCu exhibits superior mass activity (MA) of 0.62 mA μg−1 and extended stability with a positive shift (10 mV) in half-wave potential after 20,000 cycles. Additionally, it exhibits excellent MOR-MA (3335.9 mA mg−1) with 62.3% retention after 10,000 cycles, effectively competing with reported catalysts. Theoretical studies clarify the electronic strain transformation and its influence on adsorption energies of reaction intermediates on PdCu and DA PdCu during ORR and MOR, crucially correlating with experimental findings. The alloying-dealloying process in 2D-layered PdCu is a promising strategy to enhance the structure-activity relationship for improved multi-functional electrocatalysis with greater endurance. © 2024

This study presents a novel and straightforward approach to fabricate ultrafine, sharp-edged microneedle-like gold nanodendrites (Au NDs) on a homemade flexible screen-printed carbon electrode (FSPCE) using a one-step electrochemical deposition method. This aid to probe direct electrochemical oxidation and sensing of hydrazine. Effective monitoring of hydrazine is vital for risk reduction, safeguarding water quality, and ensuring safety in industrial and environmental application. The Au NDs@FSPCE offers a cutting-edge approach as an electrochemical sensor for hydrazine detection, facilitating the direct growth of Au NDs without reliance on binders or additional reductants. This advanced modification enhances the FSPCE with superior mechanical strength, excellent conductivity, tunable composition, and significantly improved electrochemical performance, establishing it as a highly efficient and reliable platform for hydrazine sensing. The Au NDs@FSPCE exhibited outstanding electrocatalytic performance at + 0.40 V with a higher oxidation current for hydrazine sensor. LSV studies revealed a detection limit of 0.46 µM, high sensitivities of 43.73 µAµM−1cm−2 and a rapid response time, and a broad linear range from 100 µM to 1500 µM. While chronoamperometry offered two linear ranges (10–90 µM and 190–1790 µM), with lower LOD of 10 nM. The sensor also demonstrated excellent long-term stability, strong reproducibility, and robust resistance to interference. Moreover, the Au NDs@FSPCE was successfully utilized to determine hydrazine in water samples. © 2025 Elsevier B.V.

In recent years, there has been notable progress in developing advanced catalyst materials and improving the performance of Pt-based catalysts for the oxygen reduction reaction (ORR). ORR is pivotal for achieving high energy conversion efficiency in fuel cells and metal-air batteries. Despite extensive research, balancing the activity and stability of electrocatalysts remains challenging. Due to the high cost and limited availability of Pt, there's a focus on developing Pt alloys, hybrid catalysts, and nanostructured materials with enhanced catalytic activity and utilization using cost-effective methods. Hybridizing multiple active components with Pt shows promise for achieving synergistic effects and meeting high-performance targets set by the U.S. Department of Energy for 2025. This review aims to present recent advances and assess the significance of supported and support-free Pt-based electrocatalysts for ORR. It focuses on carbon, inorganic, and hybrid support materials, as well as support-free metal nanostructures, highlighting their key features and catalytic potential. This offers valuable insights into developing novel Pt-based hybrid electrocatalysts for superior ORR performance in energy conversion and storage applications. © 2024 Elsevier B.V.