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Currently, there are still many limitations in the research of conductive metal-organic frameworks (MOFs) in the field of electrocatalysis. On the one hand, most MOFs have a solid construction, seriously hindering their mass transfer process. On the other hand, innate bonding is not conducive to the optimization of electronic structures and the excitation of intrinsic active sites. Therefore, external/internal dual-control of MOFs is urgently needed to break the shackles of their activity. Herein, the hollow RuCoCu-MOF/CF nanorods with tunable cavities are directionally constructed by a self-sacrificial template method. Benefiting from the exact morphological control and the unique Ru–O–Co bond bridge, RuCoCu-MOF/CF exhibits superior performances for alkaline hydrogen evolution reaction (HER) and urea oxidation reaction (UOR). Surprisingly, a record-breaking voltage of 1.402 V drives a current density of 10 mA cm−2 for urea-assisted overall water splitting under alkaline conditions, greatly promoting the development of energy-efficient hydrogen production technology. This work firstly constructed the MOF-based self-supporting electrode with ultra-high urea-assisted hydrogen production and urea degradation performances via the dual controls of the cavity size and chemical bond bridge. This points out the direction for the development of unique integrated electrodes for both hydrogen production and decontamination. "External and internal dual-controls" strategy of the cavity size and chemical bridge construction in RuCoCu-MOF nanorod achieves bifunctional catalysis of urea-assisted energy-saving hydrogen production and urea decomposition. Surprisingly, the unique structure and the formation of the Ru–O–Co bond bridge make RuCoCu-MOF/CF only need a voltage of 1.402 V to reach a current density of 10 mA cm−2 in the energy-efficient HER||UOR electrolyzer, this excellent value represents the highest performance of overall water splitting under alkaline conditions. Besides, RuCoCu-MOF/CF also achieves 2.21 times higher HER activity than commercial Pt/C/CF and splendid UOR properties in the alkaline solution. [Display omitted] • The controllable cavity was constructed by the balance of dissolution-coordination and nucleation-growth processes. • The Ru–O–Co bond bridge as the electron channel optimizes the electronic configuration. • RuCoCu-MOF/CF achieves the record-breaking urea-assisted overall water splitting performance (V 10 = 1.402 V). • RuCoCu-MOF/CF achieves the ultra-low overpotential of 11.6 mV at η 10 for HER, which is better than that of Pt/C/CF. • The ultra-low onset potential of 1.32 V is displayed in RuCoCu-MOF for UOR. [ABSTRACT FROM AUTHOR]

• A capture & ions exchange strategy is used to construct Ru@HMCS/Ru-CoP with rich Ru form. • Ru nanoparticles and Ru dopants synergistically optimize the alkaline HER kinetics. • The unique core–shell structure enhances the conductivity and structural stability. • The η 10 value of Ru@HMCS/Ru-CoP is 2.9 mV, which is 48.8 mV lower than Pt/C. It is challenging to synchronously introduce Ru nanoparticles with strong H* adsorption ability and Ru dopants with excellent electronic regulation to improve hydrogen evolution reaction (HER) performance. With these in mind, this work creatively adopts the capture&ions exchange strategy to construct the Ru@HMCS/Ru-CoP catalyst with the Ru nanoparticles-coated hollow mesoporous carbon spheres (HMCS) shell and the Ru-doped CoP core. Notably, Ru nanoparticles and Ru dopants synergistically promote the optimization of HER kinetics. Moreover, the unique core–shell structure effectively increases the active area, conductivity, and structural stability of Ru@HMCS/Ru-CoP. As expected, the η 10 value of Ru@HMCS/Ru-CoP catalyst (2.9 mV) is 48.8 mV lower than that of Pt/C (51.7 mV). In summary, this work greatly improves the utilization of noble metal atoms and points out the direction for the development of electrocatalysts with low-load noble metal content. [ABSTRACT FROM AUTHOR]

Single‐atom catalysts (SACs) are widely studied in various chemical transformations due to their high catalytic activity and atom utilization. However, modulating the catalytic performance of catalysts by adjusting the microenvironment remains a great challenge. In this paper, a novel master‐double guest vulcanization‐assisted strategy is reported for synthesizing Fe single‐atom catalysts on N,S codoped porous hollow leaf carbon (FeSA/N,S‐PHLC) with highly exposed FeN3SOH sites. Fe(mIm) (guest I) is loaded on the surface of ZIF‐L (host) and then trithiocyanuric acid (TCA, guest II) is bonded with Fe(mIm), and the resulting ZIF‐L@Fe(mIm)@TCA precursors can be converted to FeSA/N,S‐PHLC with controllable structures. In addition, XPS analysis yield an increase in pyridine N content in FeSA/N,S‐PHLC compared to FeSA/N‐PHLC. It can be demonstrated by theoretical calculations that the N,S‐coordinated axially hydroxy‐coordinated asymmetric Fe centers synergistically with the abundance of pyridinic nitrogen facilitate the adsorption and desorption of oxygen intermediates, and the 3d orbitals of the Fe active centers can be optimized. The prepared FeSA/N,S‐PHLC catalyst has a half‐wave potential (E1/2) of 0.91 V under alkaline conditions, and E1/2 = 0.75 V under acidic conditions. It shows excellent cycle stability (882 h) and power density (217 mW cm−2) in the assembly of zinc–air battery (ZABs) devices. [ABSTRACT FROM AUTHOR]

It is a great challenge to induce the formation of the RuP4 phase and realize the construction of a metal‐rich phase/phosphorus‐rich phase‐ruthenium phosphide heterostructure by directional regulation of the proportion of P and metal atoms. The ultra‐high conductivity of Ru2P and the excellent ability of V‐doped RuP4 to absorb/desorb H* are confirmed by density functional theory (DFT) calculations, which laid a theoretical foundation for the construction of a unique Ru2P/V‐RuP4 structure to accelerate HER reaction kinetics. This work innovatively uses the V‐doping strategy to induce the formation of RuP4 phase with high intrinsic activity, and finally construct V‐RuxPy nanosheets with rich Ru/Ru2P/V‐RuP4 heterostructures. Thanks to the rich Ru/Ru2P/V‐RuP4 heterostructure and the optimization of V dopants, the V‐RuxPy catalyst only needs 180 mV to obtain an industrial‐grade current density of 1 A cm−2. In summary, this work provides a new idea for the design and performance optimization of ruthenium‐based catalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • a/c-RuCoMo y O x /NF was synthesized by coprecipitation-microwave method. • Microwave time affects the transition from crystalline to amorphous structure. • a/c-interface and electron interaction make a/c-RuCoMo y O x /NF have mighty activity. • The η 10 value of a/c-RuCoMo y O x /NF is 39 and 166 mV for HER and OER. Due to the vast difference in structure and the unique electronic state at the heterointerface, the amorphous/crystalline (a/c) heterostructure exhibits excellent potential in electrocatalysis. However, there are great challenges in constructing the material with ample a/c-heterointerfaces and controllably modulated a/c-heterointerface region through a simple one-step method. Herein, the a/c-RuCoMo y O x /NF (nickel foam) electrocatalyst is synthesized by the coprecipitation-microwave treatment method. Notably, microwave time directly affects the ratio of amorphous region (RuCoMoO x) to crystalline region (CoMoO 4 and CoO). Surprisingly, the a/c-RuCoMo y O x /NF with abundant crystallinity/amorphous heterointerfaces exhibits the ultralow η 10 values of 39 and 166 mV for HER and OER, which are 0.5-fold and 0.63-fold lower than that of Pt/C-NF and RuO 2 -NF benchmarks, respectively. Overall, this work provides a novel idea and convenient method for the construction of amorphous/crystalline heterointerfaces with modulated interface region, and guides the direction for the preparation of superior electrocatalysts by regulating the a/c-heterointerface region. [ABSTRACT FROM AUTHOR]

Transition metal nitrides (TMNs) have attracted great attention as ideal active materials in the field of electrocatalysts in recent years due to their excellent electrical conductivity, wide band gap and adjustable morphology. Pure phase Co 4 N nanoparticles encapsulated nitrogen-doped carbon (NC) nanotubes (Co 4 N@NC) were in-situ synthesized by one-pot method. In this paper, the morphology of carbon nanotubes is controlled by adjusting the pyrolysis time, so that more active sites are exposed on carbon nanotubes. Thus, the cobalt nitride catalyst with excellent catalytic performance for hydrogen evolution reaction (HER) in acidic electrolyte was obtained. In summary, due to the protection of mesoporous nitrogen-doped carbon to Co 4 N nanoparticles, large electrochemically active surface area, good conductivity and more exposed active sites, Co 4 N@NC possesses excellent HER performance in acidic electrolytes. The overpotential of Co 4 N@NC at the current density of 10 mA cm−2 is 117 mV (η 10), and it shows long-term stability in 0.5 M H 2 SO 4 solution for 50 h. This study provides a strategy for the development of catalysts for the controllable synthesis of high-performance transition metal nitrides. [Display omitted] [ABSTRACT FROM AUTHOR]

Co and N co-doped RuO 2 nanosheets with rich V O (N,Co-RuO 2 -V O) were constructed by the 'melting-quenching' method. Thanks to the synergistic optimization of the electronic configuration of Ru and the reaction path of the basic HER by V O and N dopants, N,Co-RuO 2 -V O exhibited an impressive HER activity of 2208.63 mA m g R u - 1 mass activity at 100 mV, which was 8.05-fold that of Pt/C (274.2 mA m g P t - 1 ). [Display omitted] • Co,N-RuO 2 nanosheets with rich O defects were prepared by melting-quenching. • V O and N dopants synergistically optimized the electronic structure of Ru atoms. • The Ru-N dual active sites mechanism accelerates alkaline HER. • The mass activity of N,Co-RuO 2 -V O was 8.05-fold that of Pt/C due to the of N and V O. • N,Co-RuO 2 -V O obtained an industrial current density of 1 A cm−2 at only 148.6 mV. Optimizing the electronic structure of Ru by introducing N dopants or O vacancies (V O) into RuO 2 is expected to be a promising strategy to stimulate the hydrogen evolution reaction (HER) performance. However, it is a challenge to develop a fast and low-energy method to simultaneously achieve the construction of N dopants and V O. This work was the first to optimize the quenching technique for achieving the co-introduction of V O and N in Co-RuO 2 nanosheets (N,Co-RuO 2 -V O). Related characterizations confirmed that V O and N dopants synergistically optimized the electronic configuration of Ru and the reaction path of alkaline HER. As expected, the mass activity of N,Co-RuO 2 -V O (2208.63 mA m g R u - 1 ) was 8.05-fold that of Pt/C at 100 mV for alkaline HER. Surprisingly, N,Co-RuO 2 -V O required only 148.6 mV to achieve an industrial-grade current density of 1 A cm−2, which was much lower than the commercial Pt/C catalyst (312 mV). Overall, this work provides an energy-efficient new strategy for the development of Ru-based catalysts with ampere-level currents. [ABSTRACT FROM AUTHOR]

[Display omitted] • Introducing Co and P to activate inert Cu-based nanowires to achieve efficient HER/OER. • Co-doped Cu 3 P nanospheres stacked into nanochains by through a valid approach. • Prepared catalyst has excellent HER/OER activity and long term stability. Developing durable, effective and inexpensive electrocatalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are crucial for the advancement of water splitting as a solution to the energy shortage. In this study, nanospheres stacked into nanochains are successfully prepared by oxidative corrosive engineering, solvothermal, and following calcination process (Co-Cu 3 P/CF). The unique nanochain structure facilitates growing the specific surface area, thereby exposing plenitude active sites. The introduced phosphorus (P) and Co ions can alter the electronic characteristics of metal phosphides, not only can accelerate the electron transport of the catalysts, but speed up the reaction kinetics. Thus, the prepared Co-Cu 3 P/CF exhibits low overpotentials, with 240/84 mV, in alkaline media for OER/HER to attain 10 mA cm−2. In alkaline freshwater/seawater, the self-assembled electrolyzer needs only 1.51/1.58 V to achieve 10 mA cm−2. This work provides an approach for the preparation of high-performing and economical electrocatalysts. [ABSTRACT FROM AUTHOR]

Developing efficient, stable and ideal urea oxide (UOR) electrocatalyst is key to produce green hydrogen in an economical way. Herein, Ru doped three dimensional (3D) porous Ni 3 N spheres, with tannic acid (TA) and urea as the carbon and nitrogen resources, is synthesized via hydrothermal and low-temperature treated process (Ru–Ni 3 N@NC). The porous nanostructure of Ni 3 N and the nickel foam provide abundant active sites and channel during catalytic process. Moreover, Ru doping and rich defects favor to boost the reaction kinetics by optimizing the adsorption/desorption or dissociation of intermediates and reactants. The above advantages enable Ru–Ni 3 N@NC to have good bifunctional catalytic performance in alkaline media. Only 43 and 270 mV overpotentials are required for hydrogen evolution (HER) and oxygen evolution (OER) reactions to drive a current of 10 mA cm−2. Moreover, it also showed good electrocatalytic performance in neutral and alkaline seawater electrolytes for HER with 134 mV to drive 10 mA cm−2 and 83 mV to drive 100 mA cm−2, respectively. Remarkably, the as-designed Ru–Ni 3 N@NC also owns extraordinary catalytic activity and stability toward UOR. Moreover, using the synthesized Ru–Ni 3 N@NC nanomaterial as the anode and cathode of urea assisted water decomposition, a small potential of 1.41 V was required to reach 10 mA cm−2. It can also be powered by sustainable energy sources such as wind, solar and thermal energies. In order to make better use of the earth's abundant resources, this work provides a new way to develop multi-functional green electrocatalysts. [Display omitted] • The synthesized electrocatalyst exhibits porous specific sphere morphology to exposed abundant active sites. • The prepared electrocatalyst presents excellent electrocatalytic performances toward HER, OER and UOR. • Small overpotential is required to drive overall water-splitting under the urea assistance with remarkable stability. • Sustainable energies are investigated to power the electrolyzer for hydrogen generation. [ABSTRACT FROM AUTHOR]

Using low cost and high efficiency non-precious bimetallic phosphosulphide as electrocatalyst for hydrogen evolution reaction (HER) is not only convenient but also environment-friendly for industrial production. Therefore, we propose a simple and efficient method to prepare a series of Cu-doped bimetallic phosphosulphide nanosheet arrays on nickel foam (CuNiS@Ni 2 P/NF). The CuNiS@Ni 2 P/NF exhibits the superior HER performance with appropriate doping amount of Cu. It just needs a potential of 144 mV to obtain the current density of 10 mA cm−2 in 1.0 M KOH, which is smaller than that of CuNiS@Ni 2 P/NF-0.25 (206 mV) and CuNiS@Ni 2 P/NF-0.125 (219 mV). The excellent HER performance of CuNiS@Ni 2 P/NF nanosheet arrays can be ascribed to: (i) the moderate Cu-doped effectively optimized the electronic structure and morphology of the electrocatalyst; (ii) typical nanosheet arrays structures exposing more active sites; (iii) the high immanent activity excited by the multi-component synergy. • Cu-doped bimetallic phosphosulphide nanosheet arrays on Ni foam has been prepared. • The moderate amount of Cu doping could optimize the electronic structure of the product. • The typical structure and multi-component synergy contribute to the enhanced performance. [ABSTRACT FROM AUTHOR]

• NiCo-LDH decorated NiCoS nanorods with hierarchical structure has been prepared. • The moderate amount of NiCo-LDH by electrodeposition could enhance the activity. • The synergistic effect of the composite contribute to the enhanced performance. As the key step in the overall water splitting system, hydrogen evolution reaction (HER) has become one of the main methods of hydrogen production in industrial applications. Here, through the strong coupling between NiCo-LDH nanosheets and NiCoS nanorods, the three-dimensional heterogeneous structure formed by the composite can provide a large catalytic specific surface area. The modification of LDH lamellar will provide abundant edge active sites and enhance its structural stability. The synergistic effect of NiCo-LDH and NiCoS can optimize the electronic structure and promote mass transfer and water cracking. Benefiting from the above points, the NiCoS@NiCo-LDH/NF obtained showed the significant boost in HER process. It only required 99 mV to reach current density of 10 mA·cm−2 and maintained excellent durability for 24 h for HER, which proved NiCoS@NiCo-LDH/NF was a cost-free, high-efficient and outstandingly stable HER catalyst in basic solution. [ABSTRACT FROM AUTHOR]

The development of phosphide-based electrocatalyst with excellent properties and good stability under both acidic and alkaline condition is the hotspot of recent research. Herein, we synthesized N doped CoP coated with carbon nanotubes (CoP@NC) electrocatalyst for hydrogen evolution reaction (HER), in which, the ZIF-67 (ZIF = zeolite imidazole skeleton) nanoparticles wrapped Co-MOF (MOF = metal-organic skeleton) nanorods has been used as precursor. The improvement of catalytic performance of N-doped CoP can be attributed to the fact that the introduction of N can optimize the electronic structure and the in-situ grown carbon nanotubes can improve charge transfer rate and avoid the agglomeration of active units. In addition, the effect of phosphorization temperature and the amount of carbon nanotube on the electrochemical activity of the samples were also investigated, and the obtained CoP@NCs only required low overpotential of 250 mV and 234 mV to drive the current density of 100 mA cm−2 under acidic and basic conditions, respectively. This work opens up an efficient paradigm for optimizing the performance of electrocatalysts. • N doped CoP coated with carbon nanotubes (CoP@NC) has been synthesized. • The in-situ formed carbon nanotubes could efficiently improve the charge transfer rate. • The use of Co-MOF in the core part could efficiently the accumulation of active phase. • The carbonization atmosphere has an obviously effect on the electrocatalytic performance. [ABSTRACT FROM AUTHOR]