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Catalysts with high catalytic activity and low cost are extremely significant for hydrogen production by water cracking. In this work, through simple electrospinning and carbonization methods, Ru with excellent catalytic activity is dispersed onto Fe4C to form Ru–Fe4C nanoparticles loaded on N-doped carbon nanofibers (Ru–Fe4C/NCNF), so that Ru can expose more active sites and thus improve HER catalytic activity. Meanwhile, the addition of low-cost Fe can reduce the use of noble metal Ru, thereby reducing the catalyst cost. On the other hand, the prepared Ru–Fe4C/NCNF can be used as a self-supporting working electrode and shows good stability. The experimental results show that the prepared Ru–Fe4C/NCNF can drive a current density of 10 mA cm−2 with only 106 mV in 1 M KOH, and more importantly, only 254 mV can produce a current density of 100 mA cm−2. At the same time, it shows excellent stability after continuously working for 100 h at a current density of 100 mA cm−2. This work provides a new thought to synthesize economical catalysts with high catalytic activity. [ABSTRACT FROM AUTHOR]

Exploring efficient and economical electrocatalysts to replace noble metal electrocatalysts has become a major research focus nowadays. In this paper, Ru-doped Co nanoparticles loaded on carbon nanosheet (CNS) in-situ grown on carbon nanofibers (Ru–Co@CNS/CNFs) were constructed as a self-supporting working electrode for high-efficiency hydrogen evolution. The prepared Ru–Co@CNS/CNFs possessed excellent catalytic activity with only 78 mV overpotential at 10 mA cm−2 current density and good stability with only 102 mV voltage attenuation at 100 mA cm−2 current density for 100 h continuous operation. The excellent catalytic performance could be attributed to the unique microstructure of the nanosheets in-situ grown on the nanofibers, it resulted in a higher Co surface density of 1.28 mg cm−2, indicating more loading of metal to improve catalytic activity of HER, and the formed Ru-doped Co nanoparticles could be evenly distributed on the carbon nanosheets to prevent the aggregation of nanoparticles, which could expose more active sites. Additionally, the density functional theory (DFT) calculations revealed Ru doping could accelerate the dissociation of water, optimize the adsorption energy of hydrogen intermediates and improve the kinetics of the HER reaction. This work provides a new approach to reduce the use of noble metals while improving the catalytic performance of catalysts. [Display omitted] • Microstructure of nanosheets in-situ grown on nanofiber was synthesized by electrospinning and immersion method. • The unique microstructure loaded more metal content and exposed more active site. • Ru doping accelerated water dissociation, optimized ΔG H* , and improved HER reaction kinetics. • The Ru–Co@CNS/CNFs catalyst possessed excellent catalytic performance (ƞ 10 = 78 mV, ƞ 100 = 228 mV). • It showed exceptional stability after testing for 100 h at the density of 100 mA cm−2. [ABSTRACT FROM AUTHOR]

The development of dual-function catalysts with high activity and durability is essential in overall water splitting applications. In this work, FeCoNiPtRu HEA was rapidly synthesized on carbon support by carbothermal shock process. The synergistic interaction among metal elements enhanced the catalytic activity. The catalyst demonstrated overpotentials of 104 mV for HER and 331 mV for OER at 10 mA cm−2. In addition, FeCoNiPtRu HEA was aimed on carbon paper and the nanoparticles were encapsulated by a carbon layer with a stability of up to 100 h. Finally, as a dual-function catalyst, when applied as both the cathode and anode in overall water splitting (OWS), FeCoNiPtRu demonstrated a voltage of 1.69 V at 10 mA cm−2. This work demonstrates the significant potential of high-entropy alloy catalysts in hydrogen production through overall water splitting. • FeCoNiPtRu bifunctional catalyst was synthesized on carbon paper using the carbothermal shock method. • The synergistic effect of the high-entropy alloy improved and optimized the electrochemical performance of the catalyst. • The stability and oxidation resistance of the catalyst were promoted by aiming the high-entropy alloy on the carbon paper. • It represented excellent catalytic activity in the overall water splitting (η 10 =1.69 V). [ABSTRACT FROM AUTHOR]

Transition metal phosphides (TMPs) are a promising catalyst material for the hydrogen evolution reaction (HER). In this study, we introduced inexpensive red phosphorus (P 4) into a homogeneous solution as a phosphorus source. Using the electrostatic spinning technique combined with high temperature carbonization, we successfully prepared self-supported carbon nanofibers doped with nitrogen (N) and loaded with ruthenium (Ru)-modified cobalt phosphide (Co 2 P) nanoparticles catalysts (Ru@Co 2 P/CNFs). The Ru@Co 2 P phosphide nanoparticles were evenly distributed on the surface of the carbon fibers, forming a three-dimensional network structure. The synergistic effect between the Ru and Co 2 P systems resulted in excellent catalytic activity and stability for the hydrogen evolution reaction in alkaline solutions. The N-doped conducting carbon matrix and large specific surface area of the active sites contributed to this enhanced performance. The Ru@Co 2 P/CNFs catalysts only required an overpotential of 48 mV at a current density of 10 mA cm−2, outperforming the noble metal platinum/carbon (Pt/C) catalysts, which required an overpotential of 52 mV. Furthermore, the Ru@Co 2 P nanoparticles were protected by a carbon layer, preventing catalyst corrosion during long-term operation. The HER performance of the Ru@Co 2 P/CNFs catalysts remained stable even after 40 h of continuous operation, demonstrating their long-lasting stability. This research introduces a new approach to developing cost-effective and highly active self-supported network-structured phosphide catalysts. • Anchoring Ru@Co 2 P nanoparticles on carbon substrates by electrostatic spinning and high-temperature carbonization techniques. • Ru@Co 2 P/CNFs showed excellent HER activity in alkaline media (η10 = 48 mV, 63.3 mV dec-1). • Ru@Co 2 P/CNFs showed excellent HER activity in alkaline media (η10 = 48 mV, 63.3 mV dec-1). • Carbon layer encapsulation and protection for enhanced conductivity and long-lasting stability. [ABSTRACT FROM AUTHOR]

• Mainly reviews the design and synthesis methods of the latest heteroatom-doped water electrolysis catalysts. • Focusing on the design, synthesis strategies and the mechanism of improving catalytic activity. • The reaction mechanism of water electrolysis at different pH and general methods for evaluating catalytic performance are briefly reviewed. The development of clean and renewable new energy to solve the shortage of fossil energy and environmental pollution is an important research direction in the future. Hydrogen energy has been regarded as a kind of future energy because of its excellent characteristics of pollution-free and high calorific value. In addition, the electrolyzed water technology can also be combined with renewable energy sources such as solar energy to achieve complete recycling of hydrogen energy. In actual production, the realization of efficient water splitting relies to a large extent on the low-cost, high-activity and durable hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) reaction catalysts. Recently, heteroatom-doped transition metal-based water electrolysis catalyst materials have shown excellent electrocatalytic performance and durability for HER and OER, showing great potential for replacing precious metal-based catalysts. This article reviews the application of heteroatom doping strategies in transition metal-based catalytic materials and their latest research progress. First, summarize the internal relationship of heteroatom doping strategy to the morphology and catalytic activity of electrolyzed water catalytic materials. Then, the preparation process of heteroatom-doped transition metal-based catalytic materials for water electrolysis and the reasons for the improved performance and related mechanisms are discussed. Finally, the opportunities and challenges for the future development of heteroatom-doped transition metal-based catalytic materials are emphasized from the perspectives of catalytic mechanism and improvement measures. [ABSTRACT FROM AUTHOR]

• The heterogeneous catalysts were prepared by hydrothermal method and phosphating method. • Ni 2 P@MoS 2 /CC exhibits outstanding HER activity and strong stability in 1 M KOH. • Heterostructures can realize electron synergy between different components. • The HER performance of heterogeneous catalysts is better than that of single component catalysts. Efficient and inexpensive electrocatalysts play an important role in electrolysis of water and hydrogen evolution reaction. The catalytic activity of electrocatalyst can be improved by adjusting the electronic structure and increasing the active center. In this study, Ni 2 P nanosheets were grown on carbon cloth through straightforward solvothermal, and tiny MoS 2 nanosheets were uniformly covered on Ni 2 P nanosheets by in-situ growth method to form heterogeneous electrocatalyst (Ni 2 P @ MoS 2 /CC). The results show that Ni 2 P @ MoS 2 /CC had more active sites than Ni 2 P/CC and MoS 2 /CC catalysts. In addition, the interface interaction based on heterogeneous structure promotes its charge transfer kinetics. In alkaline electrolyte, Ni 2 P @ MoS 2 /CC electrocatalyst had good HER performance. At a current density of 10 mA cm−2, the overpotential was 99 mV, and the Tafel slope was 97 mV dec−1. In addition, the catalyst showed excellent electrochemical stability, with no significant loss of activity after 2000 cyclic voltammetry tests and 50 h i-t tests. [ABSTRACT FROM AUTHOR]