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The interaction between Ir and La via O atoms as a bridge in a-IrOx/LaCO3OH boosts the acidic OER activity of a-IrOx.

For high-efficiency NH3 synthesis via ambient-condition electrohydrogenation of inert N2, it is pivotal to ingeniously design an active electrocatalyst with multiple features of abundant surfacial deficiency, good conductivity and large surface area. Here, oxygen-deficient SnO2 nanoparticles encapsulated by ultrathin carbon layer (d-SnO2@C) are developed by hydrothermal deposition coupled with annealing process, as promising catalysts for ambient electrocatalytic N2 reduction. d-SnO2@C exhibits high activity and excellent selectivity for electrocatalytic conversion of N2 to NH3 in acidic electrolytes, with Faradic efficiency as high as 12.7% at −0.15 V versus the reversible hydrogen electrode (RHE) and large NH3 yield rate of 16.68 μg h−1 mgcat−1 at −0.25 V vs. RHE in 0.1 M HCl. Benefiting from the structural superiority of enhanced charge transfer efficiency and optimized surface states, d-SnO2@C also achieves excellent long-term stability.

Engineering lattice strain, especially when it combines with the lattice distortion and vacancy (LDV) induced by locally unbalanced Coulomb forces (LUCFs), can improve the local coordination environment of atoms to achieve synergistically active sites and dynamic regulation of electrocatalysts, which are beneficial to high-performance bifunctional water splitting. Considering that Ni-based selenides possess abundant variable valence states, the Nb/Fe diatomic heterogeneous spin states are purposely introduced to produce LUCFs for improving the electronic coordination environment of the materials. The as-prepared Nb/Fe co-doped Ni-Ses (NbFe-Ni

Electrochemical water splitting, as a promising approach to convert renewable electricity sources into chemical energy, is limited by bottleneck reaction of oxygen evolution (OER), and requires efficient/low-cost catalysts to accelerate OER dynamics. Metallic Ni, generally as the cathode of industrial alkali electrolyzer toward H2 production, is affordable yet inactive for anodic OER process. Enabling Ni metal with high OER activity directly serving as the anode will be an exciting progress, and undoubtedly full of challenges. Here, unexpectedly, metallic Ni demonstrates OER vitality through a superficial morphological reconstruction of Ni foam (NF) via hydrothermal-etching. The surface morphological change achieves Ni hierarchical nanosheet@nanoparticle array structure (r-Ni-1), ensuring the realization of optimal electrolyte contact and more surface exposure. More importantly, such configuration benefits for further achievement of fast transformation (in several seconds) into metal oxides and/or (oxy)hydroxides during the catalysis which are believed as the real active species. Above-mentioned in-situ transformation for conventional NF generally requires high-temperature treatment or long-term electrochemical activation for several hours. The catalytic performance of r-Ni-1 indeed outperforms most bimetallic catalysts with overpotential of 330 mV to yield 60 mA cm−2 in 1.0 M KOH, and it shows no obvious decay after a 60 h test. Our findings not only present a high-performance OER electrocatalyst, but also offer a possibility toward the simple preparation of anode materials for scale-up alkali electrolyzers.

Lattice disorder engineering on highly crystalline texture toward high-efficiency N2-to-NH3 electrocatalysis is tremendously challenging. Here, abundant lattice disturbances were established on an ultrafine Nb2O5 nanoparticle by Cu substitution. Cu-Nb2O5 anchored on a carbon material (Cu-Nb2O5@C) exhibits excellent activity and high selectivity for N2 electroreduction to NH3 with a yield rate of 28.07 μg h-1 mg-1 and a faradaic efficiency (FE) of 13.25% at -0.2 V vs. reversible hydrogen electrode (RHE) in acidic electrolyte. Cu-Nb2O5@C presents superb durability with no obvious change in catalyst constituents and structure after N2 reduction as confirmed by ex situ characterization studies. The excellent catalytical performance should originate from structural superiority of lattice turbulence for more active sites and optimized electronic state as well as good conductivity of carbon support. Meanwhile, in neutral electrolyte, the NH3 FE also reaches up to 10.29% at the same potential.

Designing highly efficient, stable and low-cost bifunctional electrocatalysts based on in situ microstructure evolution, especially achieving partial lattice dislocation on a highly crystalline texture, to catalyze the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is challenging. Herein, catalysts with the Ni3Fe alloy embedded in Ni3FeN ultrathin nanosheets (∼1 nm) were fabricated through thermal ammonolysis treatment of cation-vacant monolayered NiFe layered double hydroxides. The emergence of the Ni3Fe alloy during the annealing process unavoidably leads to strain output to adjacent microstructures in ultrathin nanosheets, contributing to the formation of lattice dislocations. Such lattice defects, combining the ultrathin 2D morphology and synergistic interfacial effect between Ni3FeN and Ni3Fe, endow the electrocatalyst (d-Ni3FeN/Ni3Fe) with excellent electrocatalytic performance for both the OER and HER in alkaline media, requiring overpotentials of 250 mV and 125 mV to drive a current density of 10 mA cm−2 in 1 M KOH, respectively. The water electrolyzer with d-Ni3FeN/Ni3Fe as the cathode and anode yields a current density of 10 mA cm−2 at a low cell voltage of 1.61 V, and exhibits excellent durability of over 90 h, outperforming the commercial IrO2‖Pt/C cell. The present study offers a new trial of lattice defect engineering to develop high-performance non-precious bifunctional electrocatalysts for overall water splitting.

Ingeniously designing a water-oxidation catalyst with advantages of a large surface area, multicomponent synergy, and optimized electronic structure, especially utilizing a one-step reaction system to achieve these dominant characteristics is pivotal to high-performance electrochemical water splitting. Here, flower-like multiphase nickel hydroxide catalysts doped with Fe (Fe-α,β-Ni(OH)2) are fabricated through a one-pot solvothermal-coordination methodology. The resulting Fe-α,β-Ni(OH)2 presents excellent oxygen production activity. An overpotential of 267 mV is required to drive a current density of 30 mA cm−2. Fe-α,β-Ni(OH)2 achieves stable operation for over 20 h. The considerable OER performance should result from the unique bionic flower structure, large surface area, and Fe-doping as well as the unique phase interfaces between the α- and β-Ni(OH)2 components. Our study provides a new trial of combining several favorable structural features into one material system that benefits efficient OER catalysis based on earth-abundant Fe and Ni elements.

Designing a conductive amorphous buffer layer between crystals (or lowering the crystallinity of one component) to minimize lattice-strain influence between a highly crystalline substance and nearby constituents, thus ensuring good electronic structure towards multiphase synergistic electro-catalysis, is of tremendous importance for the construction of high-performance catalysts. Here, combining solvothermal and calcination strategies, oxygen vacancy-abundant amorphous MoO3 and non-crystal MoO2 were implanted into amorphous N,P-doped carbon as MoOx/NPC to hybridize sub-10 nm crystalline ruthenium dots (Ru-MoOx/NPC). Amorphous NPC bridges MoOx with Ru crystal to avoid the direct contact of MoOx and Ru, thus weakening the lattice strain influence. The electrochemical measurement results show that Ru-MoOx/NPC exhibits excellent catalytical capacity towards hydrogen evolution reaction (HER), which only needs overpotentials of 30 mV and 27 mV to deliver the current density of 10 mA cm−2 in alkaline and acid electrolytes, respectively, outperforming numerous recent-reported catalysts. Such superior HER activity can be attributed to structural advantages of abundant oxygen deficiency, small-sized Ru dots, conductive amorphous NPC, and weakened lattice-strain for the maximum protection of key components. This study not only presents a well-defined nanostructure with high HER activity but also offers insight into the weakening of lattice-strain effects to support the catalytical property.

Heteroatom doping is considered a typical method for improving the electrochemical properties of composites. In this work, the multi-component oxide catalyst (Ni(VO

Combining the self-sacrifice of a highly crystalline substance to design a multistep chain reaction towards ultrathin active-layer construction for high-performance water splitting with atmospheric-temperature conditions and an environmentally benign aqueous environment is extremely intriguing and full of challenges. Here, taking cobalt carbonate hydroxides (CCHs) as the initial crystalline material, we choose the Lewis acid metal salt of Fe(NO

In industry, ammonia (NH3) is currently produced by Haber–Bosch technology, which suffers from the drawbacks of high energy consumption and CO2 emission. Artificial N2 fixation in aqueous solution ...

Electrochemical reduction of CO2 into various chemicals and fuels provides an attractive pathway for environmental and energy sustainability. It is now shown that a FeP nanoarray on Ti mesh (FeP NA/TM) acts as an efficient 3D catalyst electrode for the CO2 reduction reaction to convert CO2 into alcohols with high selectivity. In 0.5 m KHCO3 , such FeP NA/TM is capable of achieving a high Faradaic efficiency (FE CH3OH ) up to 80.2 %, with a total FE CH3OH+C2H5OH of 94.3 % at -0.20 V vs. reversible hydrogen electrode. Density functional theory calculations reveal that the FeP(211) surface significantly promotes the adsorption and reduction of CO2 toward CH3 OH owing to the synergistic effect of two adjacent Fe atoms, and the potential-determining step is the hydrogenation process of *CO.

Lattice disorder engineering on highly crystalline texture toward high-efficiency N2-to-NH3 electrocatalysis is tremendously challenging. Here, abundant lattice disturbances were established on an ultrafine Nb2O5 nanoparticle by Cu substitution. Cu-Nb2O5 anchored on a carbon material (Cu-Nb2O5@C) exhibits excellent activity and high selectivity for N2 electroreduction to NH3 with a yield rate of 28.07 μg h-1 mg-1 and a faradaic efficiency (FE) of 13.25% at -0.2 V vs. reversible hydrogen electrode (RHE) in acidic electrolyte. Cu-Nb2O5@C presents superb durability with no obvious change in catalyst constituents and structure after N2 reduction as confirmed by ex situ characterization studies. The excellent catalytical performance should originate from structural superiority of lattice turbulence for more active sites and optimized electronic state as well as good conductivity of carbon support. Meanwhile, in neutral electrolyte, the NH3 FE also reaches up to 10.29% at the same potential.

Renewable‐electricity‐driven N2 reduction is an attractive approach for ambient NH3 synthesis, but active electrocatalysts are needed to enable the N2 reduction reaction. Monolithic electrodes with active components anchored on conductive supports provide many advantages like structural stability, large surface area, and low electrical resistance. Here, a novel “oxidation‐etching” strategy is proposed to carve the surface of Cu foam into structures of particles, cubes, and sheets for N2 reduction electrocatalysis. The optimal catalyst achieves a Faradic efficiency as high as 18% at −0.35 V vs reversible hydrogen electrode (RHE) and a large NH3 yield of 2.45 × 10−10 mol s−1 cm−1 at −0.40 V vs RHE in 0.1 M HCl. Notably, it also shows superior long‐term electrochemical durability, with the preservation of electro‐activity for at least 20 hours.

Interface engineering has proven an effective strategy for designing high-performance water-oxidation catalysts. Interface construction combining the respective advantages of amorphous and crystalline phases, especially embedding amorphous phases in crystalline lattices, has been the focus of intensive research. This study concerns the construction of an amorphous-crystalline FeOOH phase boundary (a-c-FeOOH) by structural evolution of iron oxyhydroxide-isolated Fe(OH)3 precursors from one-step hydrothermal synthesis. a-c-FeOOH demonstrates superb electrocatalytic activity for the oxygen evolution reaction (OER) with overpotential of 330 mV to drive a current density of 300 mA cm-2 in 1.0 m KOH, which is among the best OER catalysts and much better than the pristine amorphous or crystalline FeOOH alone. Density functional theory calculations reveal that the high-density a-c phase boundaries play a critical role in determining high OER activity.

Amorphous transition-metal (hydr)oxides have proven to be the most promising oxygen evolution reaction (OER) electrocatalysts. Here, a facile and novel strategy for the generation of porous amorphous cobalt oxide through one-step treatment of the cobalt carbonate hydroxide precursor with concentrated sulfuric acid has been reported. Benefiting from the optimized amorphous structure, the prepared catalyst exhibits an excellent water-oxidation activity in an alkaline electrolyte with the demand of 50 mV less overpotential at 10 mA cm-2 compared to that of highly-crystallized Co3O4. Compared with the 400 °C annealing process for Co3O4, the ultrafast acid treatment process within 10 seconds at room-temperature for achieving such amorphous cobalt oxide demonstrates tremendous convenience. More impressively, after continuous testing for 60 h at an overpotential of 370 mV, it still maintains a porous configuration as well as ∼92% of the original current density. Our findings not only present a high-efficiency OER electrocatalyst, but also provide a methodology with broad applicability toward the systematic study of other non-crystal oxides for green energy applications.

It is highly attractive but still remains a great challenge to develop an efficient electrocatalyst for oxygen evolution reaction under nearly neutral conditions. In this work, we report the transformation of Ni3S2 nanowire array on nickel foam into the amorphous nickel carbonate nanowire array on nickel foam (NiCO3/NF). The resulting NiCO3/NF shows high electrocatalytic activity towards water oxidation and affords current density of 50 mA∙cm‒2 at overpotential of 395 mV in 1.0 mol∙L‒1 KHCO3. Moreover, this NiCO3/NF is also durable with a long-term electrochemical durability of 60 h. This catalyst electrode achieves a high turnover frequency of 0.21 mol O2∙s‒1 at the overpotential of 500 mV.

Electrochemical N2 reduction reaction (NRR) under ambient conditions offers us an environmentally friendly route for artificial synthesis of NH3. However, up to now, few noble-metal-free electrocatalysts with satisfactory catalytic activities have been explored. In this Letter, we demonstrate that MoN nanosheets array on carbon cloth (MoN NA/CC) acts as a high-performance NRR electrocatalyst toward NH3 electrosynthesis in 0.1 M HCl under ambient conditions. This catalyst achieves a large NH3 yield of 3.01 × 10–10 mo1 s–1 cm–2 and a Faradaic efficiency of 1.15% at −0.3 V vs reversible hydrogen electrode with strong electrochemical durability and selectivity. Density functional theory calculations reveal that MoN NA/CC catalyzes NRR via the Mars–van Krevelen mechanism.

By integrating the light-absorbing semiconductor materials into the electrocatalytic network, using the photogenerated-carrier-driven strategy, and thus permitting solar energy to operate as the extra driving force, the efficiency of electrocatalytic water splitting (EWS) is expected to be improved. However, the rational plot of such integrated catalytic system remains an enormous challenge due to the spatial disparity between photocatalytic components and electrocatalytic components. Herein, a MgCo2O4@WO3 core-shell heterostructure (MCW CSHS) is constructed by the simple one-step hydrothermal coordination of the spinel oxide MgCo2O4 (as the electron acceptor) and the WO3 semiconductor (as the electron donor). The cogitatively designed MCW CSHS catalyst can effectively eliminate the spatial disparity between the two above functional components and provide significantly increased surface area and roughness, which can enhance light absorption by restraining diffuse reflection and promoting electron transfer in EWS. Under solar illumination, the electrocatalytic activity of MCW CSHS is significantly improved due to the electronic structure regulation, yielding 50 mA·cm-2 at overpotentials of 243 mV for oxygen evolution reactions and 161 mV for hydrogen evolution reactions in 1 M KOH. The solar energy enhanced electrochemical system based on bifunctional materials has a broad application prospect in the efficient H2 production by EWS.

Electrolytic hydrogen generation needs efficient and durable electrocatalysts for the hydrogen evolution reaction. In this Letter, for the first time, we report on the development of P-doped Ag nanoparticles embedded in N-doped carbon nanoflake (denoted as “P-Ag@NC”) for effective hydrogen evolution electrocatalysis. When tested in 0.5 M H2SO4, such P-Ag@NC demands overpotential of only 78 mV to drive a catalytic current density of 10 mA cm–2, which is 198 mV less than that of Ag@NC counterpart. Remarkably, this catalyst also shows strong long-term electrochemical durability with the preservation of its catalytic activity for at least 85 h. Density functional theory calculations suggest that P doping brings the optimization of hydrogen adsorption free energy to a more thermo-neutral value.

The synthesis of NH3 heavily depends on the energy-intensive Haber–Bosch process with a large amount of greenhouse gas emission. Electrochemical reduction offers a carbon-neutral process to convert N2 to NH3 at ambient conditions, but requires efficient and stable catalysts for the N2 reduction reaction. Mo-dependent nitrogenases and synthetic molecular complexes have attracted increasing attention for N2 fixation; however, less attention has been paid to Mo-based nanocatalysts for electrochemical N2 conversion to NH3. Herein, we report that MoO3 nanosheets act as an efficient non-noble-metal catalyst for electrochemical N2 fixation to NH3 with excellent selectivity at room temperature and atmospheric pressure. In 0.1 M HCl, this catalyst exhibits remarkable NRR activity with an NH3 yield of 4.80 × 10−10 mol s−1 cm−2 (29.43 μg h−1 mgcat.−1) and a faradaic efficiency of 1.9%. Moreover, this catalyst also shows high electrochemical stability and durability. Density functional theory calculations reveal that the outermost Mo atoms serve as the active sites for effective N2 adsorption.

It is highly desired to develop efficient earth-abundant electrocatalysts for the oxygen evolution reaction (OER) in alkaline media. In this communication, we report the in situ electrochemical conversion of a nanoarray of Cu(tetracyanoquinodimethane), Cu(TCNQ), an inorganic–organic hybrid, on Cu foam into CuO nanocrystals confined in a highly conductive nanoarray via anode oxidation. As a 3D catalyst electrode, the resulting CuO–TCNQ/CF shows high OER activity and demands an overpotential of only 317 mV to drive a geometrical catalytic current density of 25 mA cm−2. Notably, this catalyst also demonstrates strong long-term electrochemical durability. This study provides us with a universal strategy toward topotactic room-temperature preparation of conductive nanoarrays with confined transition metal nanocatalysts for practical applications.

In spite of recent advances in the synthesis of transition metal phosphide nanostructures, the simple fabrication of hierarchical arrays with more accessible active sites still remains a great challenge. In this Communication, we report a space-confined phosphidation strategy toward developing hierarchical CoP nanosheet@microwire arrays on nickel foam (CoP NS@MW/NF) using a Co(H2PO4)2·2H3PO4 microwire array as the precursor. The thermally stable nature of the anion in the precursor is key to hierarchical nanostructure formation. When used as a 3D electrode for water oxidation electrocatalysis, such CoP NS@MW/NF needs an overpotential as low as 296 mV to drive a geometrical catalytic current density of 100 mA cm-2 in 1.0 M KOH, outperforming all reported Co phosphide catalysts in alkaline media. This catalyst also shows superior long-term electrochemical durability, maintaining its activity for at least 65 h. This study offers us a general method for facile preparation of hierarchical arrays for applications.

It is fascinating to design and synthesize high-efficiency and noble-metal-free alkaline oxygen evolution reaction (OER) electrocatalysts. In this Communication, we describe the one-step hydrothermal synthesis of a WO3 nanoarray directly grown on conductive carbon cloth (WO3/CC) for efficient water oxidation in 1.0 M KOH. As a monolithically integrated array catalyst, WO3/CC exhibits superior OER activity demanding overpotential as low as 280 mV to afford a benchmarking catalytic current density of 10 mA cm-2. It is worth noting that WO3/CC also possesses strong electrochemical durability with 95% Faradaic yields.

The cactus-like double-shell structured SiO2@TiO2 microspheres (CDS SiO2@TiO2 microspheres) with high dielectric properties were successfully fabricated and utilized as high-performance electrorheological (ER) fluids and microwave absorbing materials. The SiO2 nanospheres with average diameters of 190 nm were synthesized by the hydrolysis of tetraethyl orthosilicate (TEOS), and used as the core for the first coating layer of TiO2 achieved by sol-gel method. The final cactus-like TiO2 layer was prepared via a hydrothermal method. The morphology of the resultant samples was characterized via transmission electron microscopy (TEM), scanning electron microscopy (SEM) and scanning transmission electron microscopy (STEM). This novel CDS SiO2@TiO2 microspheres based suspension exhibited improved ER properties compared to conventional bare SiO2 spheres.

The design and fabrication of earth-abundant and highly efficient water oxidation electrocatalysts are important for water splitting systems associated with the energy conversion and storage. In this work, we report an intercalation strategy to expand interlayer spacing of the layered structure and thus achieve great enhancement for water oxidation activity. Layered-structured nickel benzoate hydroxide nanobelts arrays on nickel foam (benzoate-Ni(OH)2/NF) are prepared by a one-step hydrothermal method. As-prepared benzoate-Ni(OH)2/NF exhibits outstanding oxygen evolution performance with the need of only 242 mV overpotential to drive a current density of 60 mA cm–2 in 1.0 M KOH, 126 mV lower than that for Ni(OH)2/NF. This catalyst electrode also has good stability with the maintenance of its catalytic activity for 27 h.

Efficient oxygen evolution reaction (OER) catalysts are highly desired to improve the overall efficiency of electrochemical water splitting. In this communication, we develop a benzoate anions-intercalated layered cobalt hydroxide nanobelt array on nickel foam (benzoate-Co(OH)2/NF) via a one-pot hydrothermal process. As a three-dimensional electrode, benzoate-Co(OH)2/NF with an expanded interlayer spacing (14.72 A) drives a high OER catalytic current density of 50 mA cm-2 at an overpotential of 291 mV, outperforming its carbonate anions-intercalated counterpart with a lower interlayer spacing of 8.81 A (337 mV overpotential at 50 mA cm-2). Moreover, this benzoate-Co(OH)2/NF can maintain its catalytic activity for 21 h.

Graphene has attracted much attention and triggered extensive anti-corrosion applications due to its excellent electrochemical stability and robust barrier for molecules and ions. In this paper, a novel polypyrrole/reduced graphene oxide (PPy/rGO) nanocomposite was successfully prepared on carbon steel as an efficient protective coating for improving the anti-corrosion property. Graphene oxide (GO) was deposited onto carbon steel via potentiostatic technique, and PPy was obtained simultaneously by oxidation polymerization. Scanning cyclic voltammetry method was adopted to reduce GO into rGO to form PPy/rGO nanocomposite coating. Due to the synergistic effect of PPy and rGO, excellent anti-corrosion performance for carbon steel in simulated seawater was obtained. Impressively, the PPy/rGO-coated carbon steel showed 7.05 times higher corrosion resistance than that of bare carbon steel and revealed the excellent protection efficiency above 95.9%. The anti-corrosion mechanism of the PPy/rGO coating was also proposed. Our results suggested that the PPy/rGO composite coatings could serve as effectively protectors for anti-corrosion of seawater, therefore, they could envision potential applications in naval architecture and ocean engineering.

Electrochemical reduction of CO

Controllably constructing the functional microscopic surfaces, especially via the escape of metal atoms from extremely stable texture to achieve super-hydrophilic interfaces, as efficient bifunctional catalysts for water splitting is a daunting challenge but critical for sustainable economic development. Based on hydrothermal coordination strategy, we take advantage of strong oxidizing property of nitrate ions to realize temperature-controllable atom-escape of metal Ni for self-assembling super-hydrophilic hydroxide FeNi–OH on nickel base as electrocatalysts of hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Such distinctive Ni source, resulting in improved ohmic contact and mechanical robustness of catalysts, in conjunction with super-hydrophilicity-accelerated bubble separation and electrolyte contact, endows the catalyst with excellent electrocatalytical activity for both HER and OER in alkaline solution. Super-hydrophilic FeNi–OH delivers the current density of 50 mA cm−2 at overpotentials of 236 mV for OER and 196 mV for HER. Water electrolysis with FeNi–OH as anode and cathode demands a cell voltage of 1.664 V to drive 50 mA cm−2 in 1.0 M KOH, continuously operating for 25 h. This study opens up an avenue in establishing super-hydrophilic structure via self-assembly of the escaped atoms, broadening the horizon on low-cost iron-containing catalyst preparation for energy conversions.

D-band-center control engineering, particularly combining both cation and anion intercalations towards heterostructure formation with simultaneous usage of Ru, N as well as F species, for optimal electronic structure as efficient hydrogen evolution reaction (HER) catalysts remains a daunting challenge but critical for renewable-energy technologies. Herein, we lay emphasis on the design of active-site electronic structure based on d-band-center shift through the construction of Co4N-CoF2 heterostructure coupled with Ru doping (Ru/Co4N-CoF2). Solvothermal coordination reaction followed by annealing course causes cooccurrence of F, N, Ru in Co neighborhood. As-obtained Ru/Co4N-CoF2 exhibits superior HER activity in alkaline electrolyte with overpotential as low as 53 mV to yield a current density of 10 mA cm−2 which is close to that of commercial Pt/C, outperforming many transition-metal-based catalysts recent-reported. Moreover, it still presents good durability with continuous operation of 22 h in 1.0 M KOH. Such excellent performance is ascribed to appropriate electron structure of Ru/Co4N-CoF2 for optimized hydrogen binding abilities on Co/Ru sites as confirmed by synchrotron-based X-ray adsorption near-edge structure and X-ray photoelectron spectroscopies. This study not only establishes highly active electrocatalysts by impacting d-band center of active sites but also provides valuable insights into the synergistic-effect protocol of doping and heterostructure strategies for d-band-center shifting.

It is highly desirable but still a challenging task to find a simple, fast and straightforward method to greatly improve the alkaline oxygen evolution reaction (OER) performance of a NiCo2O4 catalyst. In this communication, we demonstrate that developing an amorphous borate shell on a NiCo2O4 surface can boost its OER activity in alkaline media. As a 3D catalyst electrode, a NiCo2O4@Ni–Co–B nanoarray on carbon cloth needs an overpotential of only 270 mV to achieve a geometrical catalytic current density of 10 mA cm−2 in 1.0 M KOH, which is 100 mV less than that for a NiCo2O4 nanoarray. Notably, this electrode also demonstrates strong electrochemical durability, maintaining its activity for at least 100 h. The superior activity of NiCo2O4@Ni–Co–B is attributed to the amorphous Ni–Co–B shell on NiCo2O4 favoring the in situ electrochemical generation of more active species during water oxidation.

The exploration of high-performance and earth-abundant water oxidation catalysts operating under mild conditions is highly attractive and challenging. In this communication, core–shell CoFe2O4@Co–Fe–Bi nanoarray on carbon cloth (CoFe2O4@Co–Fe–Bi/CC) was successfully fabricated by in situ surface amorphization of CoFe2O4 nanoarray on CC (CoFe2O4/CC). As a 3D water oxidation electrode, CoFe2O4@Co–Fe–Bi/CC shows outstanding activity with an overpotential of 460 mV to drive a geometrical catalytic current density of 10 mA cm−2 in 0.1 M potassium borate (pH 9.2). Notably, it also demonstrates superior long-term durability for at least 20 h with 96% Faradic efficiency. Density functional theory calculations indicate that the conversion from OOH* to O2 is the rate-limiting step and the high water oxidation activity of CoFe2O4@Co–Fe–Bi/CC is associated with the lower free energy of 1.84 eV on a Co–Fe–Bi shell.

Fibrous materials usually have good mechanical, heat-resistant, acid-resistant, alkali-resistant and moisture regained properties which originate from its composition, condensed structure and crosslinking styles. However, these materials often lack of good electrical conductivity, flame retardance, anti-static and anti-radiation properties which are desired for varied specific applications. Graphene, as a new emerging nanocarbon material, has some unique properties including superb thermal and electrical conductivity, strong mechanical and anti-corrosive property, extremely high surface area etc. Therefore, graphene has attracted extensive interests in recent years. Upon modification with graphene, fibers exhibit a number of enhanced or new properties such as adsorption performance, anti-bacteria, hydrophobicity and conductivity which are beneficial for broader applications. In this review, the strategies to modify the fibers with graphene and the corresponding effects on the fibers as well as the relevant applications in varied areas were discussed.

An amorphous Co–Mo–B film on a Ti mesh (Co–Mo–B/Ti) is fabricated via one-step electrodeposition exhibiting a dramatically enhanced hydrogen evolution reaction (HER) performance in alkaline media. To attain a current density of 20 mA cm−2, such Co–Mo–B/Ti demands only an overpotential of 110 mV, 190 mV lower than that of the counterpart Co–B/Ti, with strong electrochemical durability to maintain its catalytic activity for at least 32 h.

Increasing attention has been focused on microwave absorption (MA) performance in the Ku band (12.4–18.0 GHz) due to the rapid development of radar, military aircraft and satellite communications. In this work, 2D heterostructure MoS2/graphene composites were proven to be promising full Ku band MA materials due to their superb characteristics of high dielectric loss, low density, large surface area and good thermal stability. By a simple one step solvothermal method, MoS2/graphene composites were successfully obtained, and the matched 2D structure between MoS2 and graphene could generate synergistic effects and maximize the MA properties. Only with 30 wt% of the as-prepared MoS2/graphene composites, excellent MA properties in wide frequency bands were obtained. An optimal reflection loss (RL) value of −41.9 dB was obtained at 16.1 GHz with a thickness of 2.4 mm and the RL values exceeding −10 dB were achieved in the whole Ku band (12.2–18.0 GHz) with a thickness of 2.6–3.0 mm.

The discovery of stable and noble-metal-free catalysts toward efficient electrochemical reduction of nitrogen (N