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[Display omitted] • A hydrogen-bond binding strategy is proposed to fabricate iCOF nanosheets (iCONs) and tannic acid (TA) composite membranes. • TA nanoaggregates were synthesized as hydrogen-bond binders. • Abundant hydrogen-bond interactions enable flexible connection between iCONs. • Highly interconnected hydrogen-bond networks facilitate rapid proton transport. • The membranes showed both enhanced mechanical properties and proton conductivity. Robust and highly conductive proton exchange membrane (PEM) is the unremitting pursuit of numerous electrochemical energy technologies such as fuel cell and the emerging electrochemical hydrogen compression. Ionic covalent organic framework nanosheets (iCONs) with long-range ordered nanochannels and abundant ionic groups show substantial potential as next-generation PEM materials. However, it is challenging to assemble iCONs into membranes with both robustness and flexibility due to the electrostatic repulsion and rigid framework. Herein, we propose a hydrogen-bond binding strategy to fabricate sulfonic iCON (SCON) composite membranes by co-assembling tannic acid (TA) nanoaggregates and SCONs. The abundant and dynamically reversible hydrogen-bond interactions introduced by TA nanoaggregates establish effective linkage between SCONs and allow some restricted movements, endowing membranes with remarkably improved mechanical properties. The stacked SCONs construct long-range ordered nanochannels with well-arranged sulfonic groups in membranes, and the hydrogen-bond networks further facilitate the proton transport through Grotthuss mechanism. Consequently, TA/SCON composite membranes displays significantly enhanced tensile strength of 101.9 MPa, good flexibility and high proton conductivity of 490.1 mS cm−1 at 80 °C and 100 % RH simultaneously. This hydrogen-bond binding strategy offers a promising approach to fabricate robust and highly conductive PEMs for various proton-conducting applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Forced flow processing for in-situ exfoliation and dispersion of Gt is proposed. • Backflow and extremely strong shear stress lead to the interlayer loosening of Gt. • 70 wt% of Gt in aPLA can be fully converted into uniformly dispersed GNPs. Graphene has received extensive attention from the industry due to its extraordinary physical and chemical properties. However, the development of low-cost, large-scale methods to prepare graphene and its derivatives via graphite (Gt) exfoliation is still a challenge. Herein, we propose a novel method to in-situ exfoliate and disperse Gt without any post-processing via exploiting the strong shear stress and irreducible deformation generated by the forced flow processing of highly elastic amorphous polylactide (aPLA). It is amazing that, after 8 times forced flow processing within 10 min, 70 wt% of Gt in aPLA is fully converted into uniformly dispersed graphite nanoplatelets (GNPs) with average lateral sizes of 2.28 μm and thicknesses of 8.82 nm. Mechanism analysis reveals that the combination of backflow with subsequent extremely strong shear stress results in the interlayer loosening of graphite toward continuous production of GNPs. The GNPs exhibit exceptional enhancements in the thermal and electrical conductivity of the composites. This ultra-efficient, extremely simple and solvent-free method can be scalable for industrial use. [ABSTRACT FROM AUTHOR]

[Display omitted] • 1. Electrochemical hydrogen compression (EHC) can purify and compress hydrogen in one step. • 2. Working principle and module design of EHC are described and summarized. • 3. Developments of advanced proton-conducting membranes for EHC are reviewed. • 4. Challenges, future trends and prospects of EHC are discussed. Electrochemical hydrogen compression (EHC), which can purify and compress hydrogen in one step, has aroused broad interests due to its high efficiency, compact equipment, and quiet operation. Since the concept of EHC was proposed, considerable efforts have been devoted to this field. In this review, several aspects of EHC are comprehensively discussed. Firstly, the working principle of EHC is presented with a focus on the electrode reactions, overpotentials, and performance indicators. Subsequently, the major functions, required properties, common materials and recent progress on the design and development of EHC modules are overviewed. As the key part of EHC, recent advances in proton-conducting membranes are particularly summarized, including polymeric proton exchange membranes, mixed matrix proton exchange membranes, and proton ceramic oxide membranes. The focus is on the chemical structures, proton transfer mechanisms, factors affecting performances, and applications for hydrogen purification and compression. Finally, the challenges, future trends, and prospects associated with each module of EHC are discussed. [ABSTRACT FROM AUTHOR]

[Display omitted] • Smart COF membranes were constructed via biomimetic nanochannel modulation. • Charged and switchable channels endowed COF membranes with high ion selectivity. • Pore size of photo-responsive COF membranes was controllable at angstrom level. • Photo-responsive COF membranes showed great potential in lithium extraction. Smart nanochannels can regulate ion transport behavior by external stimulus and display precise ion selectivity in biological membrane systems, but constructing artificial membranes with responsive and tunable channel remains a severe challenge. Herein, smart covalent organic framework (COF) membranes decorated with photo-responsive azobenzene derivatives (COF-Azo) were fabricated by a biomimetic nanochannel modulation (BNM) strategy, endowing membranes with charged and switchable sub-nanochannels. Under different wavelength of light, the smart COF-Azo membranes simultaneously exhibited outstanding mono/monovalent and mono/divalent ion selectivity (K+/Li+ ideal selectivity of 17.9 and Li+/Mg2+ ideal selectivity of 24.9) via closing and opening channels. The conversion of effective pore size at angstrom level is realized by photoisomerization of azobenzene. After several photoswitch cycles, the smart membranes still maintained K+/Li+ selectivity of 6.1 and Li+/Mg2+ selectivity of 20.7 in mixed salt solution, exhibiting great potentials in lithium extraction. This work may blaze a trail in constructing photo-responsive nanochannel membranes for energy-efficient ion separation. [ABSTRACT FROM AUTHOR]

[Display omitted] • A versatile coating was fabricated based on an electrostatic-coordination strategy. • The textile exhibited excellent solar/Joule heating performances properties. • The textile presented passive radiative heating properties. • The textile could protect the human body effectively in practical environments. • The research brought new insights into the development of PTM devices. The development of multifunctional textile-based personal thermal management devices is a prospective option for accurately warming the human body while effectively reducing energy consumption. However, existing multifunctional thermal management devices still face challenges in terms of high-performance integration. Here, we proposed an electrostatic-coordination-based strategy to fabricate successfully a versatile textile for body warming via sequentially covering cotton fiber with bio-based polyelectrolyte and in-situ grown copper sulfide coatings. The textiles with excellent solar/Joule heating properties and reduced infrared emissivity can efficiently heat the body in various environments and suppress thermal radiation dissipation from the body to the environment. Also, the textile realizes high-performance integration of electromagnetic shielding, UV protection, antimicrobial, and flame-retardant properties. This universal and efficient strategy provides a promising solution for the manufacture of all-day and energy-saving versatile personal thermal management devices, showing great potential for practical applications. [ABSTRACT FROM AUTHOR]

• Growth of large-sized Ge 1– x In x Bi 2 Te 4 single crystals by Bridgman method. • Ultralow κ L of GeBi 2 Te 4 driven by cation disorder and low phonon velocity. • Resonant level introduced by In-doping greatly improves electrical performance. • Achieving zT ave of 0.36 in the range of 323–573 K for Ge 0.97 In 0.03 Bi 2 Te 4 sample. Resonant level, the impurity level located inside the valence/conduction band, is an effective strategy for decoupling the electrical conductivity and Seebeck coefficient and enhancing the thermoelectric power factor. In this work, we show that In doping induces resonant level and enhances the thermoelectric performance of GeBi 2 Te 4 , a promising n-type thermoelectric material with layered structure. Single crystals grown by Bridgman method were used in this study to take the advantage of its anisotropic transport properties. An ultralow lattice thermal conductivity of ∼0.51 W m−1 K−1 at 323 K was found along the c -axis of GeBi 2 Te 4 , driven by intrinsic cation disorder and the low phonon group velocity from the relatively weak chemical bonds as well as the strong lattice anharmonicity caused by hierarchical bond orders. Both enhanced electrical conductivity and Seebeck coefficient were observed in the In-doped samples, indicating that In-doping not only increases the carrier concentration, but also introduces the resonant level that was further confirmed by the first-principles calculation. A maximum zT of ∼0.42 at 523 K and an average zT of 0.36 over 323 to 573 K were achieved in Ge 0.97 In 0.03 Bi 2 Te 4 crystal sample, ∼100% and ∼89% enhancement compared to those of pristine single crystal sample, respectively. This study demonstrates another example of resonant level for thermoelectric performance enhancement, which may be applied to other related materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ion selective COFMs were constructed via custom-tailored nanochannels strategy. • Charged, narrowed and lithiophilic channels endowed COFMs with high selectivity. • Positively charged surface prevented scaling formation on the COFMs. • The anti-scaling COFMs showed great potential in lithium extraction. Covalent organic framework membranes (COFMs) with well-defined nanochannels have infinite potential in efficient separation. However, unsuitable pore size and easily contaminated surface hamper the application of COFMs for ion separation. Herein, we report a custom-tailored nanochannels strategy for forming COF nanosheets (COFNs) with positively charged, narrowed and lithiophilic channels. The obtained COFNs can be easily assembled into free-defect and oriented COFMs via vacuum-assisted filtration method. Charged and narrowed channels augment entrance resistance of divalent cation, meanwhile, lithiophilic groups promote transport of Li+ in channels. Besides, positively charged surface disturbs the crystallization of scaling. Thus, the optimal COFM exhibited excellent water permeance of 32.1 L m−2 h−1 bar−1 and high Li+/Mg2+ separation factor of 30.2 in simulated salt-lake brine. After running in the gypsum solution, the anti-scaling COFMs showed low flux decline ratio (FDR) and the flux recovery ratio (FRR) was nearly 10% higher than NF90. This study may provide a facile regulation method for nanochannels and surface properties of COFMs, and the obtained membranes could be applied to efficient lithium extraction. [ABSTRACT FROM AUTHOR]

[Display omitted] • First attempt to realize high-titer production of inositol by co-immobilized multi-enzymes. • An inositol titer of up to 210 g/L was produced. • Prolonged enzyme lifetime decreased biomanufacturing cost. • Scaleable multienzyme immobilization for potential industrial application was proposed. Myo -inositol is widely used in food, feed, pharmaceutical and cosmetic industries, but its great potentials are restricted from its limited supplies and high prices. Inositol is the first biobased product produced by the in vitro biomanufacturing platform containing multi-enzymes in one pot on an industrial scale. However, the in vitro multi-enzyme-based biomanufacturing face the challenge of enzyme deactivation and high cost of the enzymes used. To further prolong the enzyme lifetime and decrease its biomanufacturing cost, here we developed a co-immobilized four-enzyme cocktail using biomimetic mineralized microcapsules composed of polyethyleneimine and silicate for large-scale production. The lumped enzyme half-life of the microcapsules was 55.5 h at 70 °C, which was 5.9 folds of that of the four-enzyme cocktail. An inositol titer of up to 210 g/L was produced, and the cost of enzymes used was decreased by 3.4 times. This is the first attempt to realize high-titer production of inositol by co-immobilized multi-enzymes, laying a foundation of in vitro biomanufacturing based on in vitro synthetic enzyme biosystems. [ABSTRACT FROM AUTHOR]

• A photo-activated chemodynamic therapy (CDT) was developed for cancer treatment. • A nanosheet catalyst was constructed to enable cascade catalytic reactions. • Superoxide radicals generated from photodynamic therapy was converted into H 2 O 2. • In-situ generated and endogenous H 2 O 2 induced ·OH generation for enhanced CDT. Chemodynamic therapy (CDT) has aroused extensive interest as an advanced anti-cancer approach which is featured with high tumor specificity and selectivity. However, chemodynamic therapeutic efficacy heavily relies on the level of endogenous hydrogen peroxide (H 2 O 2), which is intrinsically heterogenous and insufficient. Herein, a self-supplied H 2 O 2 enhanced chemodynamic therapeutic strategy is developed by constructing a two-dimensional (2D) sheet-like nanocatalyst to mediate catalytic cascade reactions. The cascade nanocatalyst is fabricated by integrating photosensitizer indocyanine green (ICG) and Fenton reaction catalyst Fe2+ ions into a 2D ultrathin layered double hydroxide nanoparticles (NPs). Under near infrared light irradiation, ICG not only produces cytotoxic singlet oxygen (1O 2) to damage tumor cells, but also generates superoxide radical (O 2 ·-) that is subsequently converted into H 2 O 2 by reacting with intracellular superoxide dismutase (SOD). A considerable amount of in situ self-supplied H 2 O 2 , together with endogenous H 2 O 2 , is then catalyzed by Fe2+ released from nanocatalyst to produce abundant, highly cytotoxic hydroxyl radicals (· OH) to trigger apoptosis and death of tumor cells. In vitro and in vivo evaluations manifest the cascade nanocatalyst-mediated remarkable chemodynamic therapeutic performance. Therefore, this work has demonstrated a cascade catalytic therapeutic nanoplatform enabling photoactivation-triggered H 2 O 2 self-supplied synergistic strategy for safe and efficacious tumor treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nitrogen-doped reduced graphene oxide beads (NrGOb) were fabricated by a one-step self-assembly strategy. • The lightweight NrGOBs and peroxymonosulfate system presented high activity in oxidative degradation of organic pollutants. • The catalytic beads were packed in a fixed-bed column reactor to maintain a continuous process. • Reactive radicals were identified by the quenching tests and electron paramagnetic resonance spectra. • Mechanistic studies on peroxymonosulfate activation and degradation pathways of hydroxybenzoic acid were performed. Metal-free graphene-based catalysts have demonstrated excellent performance in advanced oxidation processes (AOPs). However, the recovery and reusability of these nanocatalysts are still a major issue. In this study, three dimensional (3D) nitrogen-doped reduced graphene oxide beads (NrGOb) were synthesized via a self-assembly method and then applied in heterogeneous activation of peroxymonosulfate (PMS) for the oxidation of hydroxybenzoic acid (HBA). The materials (NrGOb) were annealed at various temperatures ranging from 500 to 1000 °C, and the resulting NrGOb derived from 800 °C (NrGOb-800) exhibited the best performance for PMS activation. To avoid the challenging recovery, the degradation experiments were also performed in a packed-bed catalytic reactor. Various reaction parameters were investigated to optimize the efficiency of the system. Electron paramagnetic resonance (EPR) and quenching tests were carried out to differentiate the contribution of reactive radicals (SO 4 •- and •OH) in the degradation process and then aided in illustrating the degradation mechanism. Finally, the stability and reusability of the catalytic beads were investigated. The efficiency slightly declined with increased cycles; however, catalyst regeneration would be able to partially restore the active sites. The results suggest the feasibility of exploiting graphene-based macrostructures on the AOPs platform for the degradation of organic pollutants in commercial wastewater treatment plants. [ABSTRACT FROM AUTHOR]

[Display omitted] • COF-based membranes are utilized for C 3 H 6 /C 3 H 8 separation for the first time. • Large-sized COF pores can achieve maximum contact between Ag+ and C 3 H 6 molecules. • High-density Ag+ facilitates C 3 H 6 confined transport along nanochannel surface. • Density differences result in asymmetric structure and directional transport. • Confined mechanism with asymmetric structure provide superior separation performance. Energy-efficient membrane technology is sought to replace or integrate with conventional energy- and cost-intensive distillation for precise propylene/propane separation. Covalent organic framework (COF)-based composite membranes (CMs) are promising candidates for the representative difficult propylene/propane separation system. However, the large-size pore of COFs cannot achieve an effective separation of gas pairs with sub-angstrom (0.2 Å) size differences. Here, we design confined facilitated transport nanochannels within COFs as productive fillers to construct CMs. The anchored high-density Ag+ carriers facilitate C 3 H 6 monomolecular high-speed transport along the nanochannel surface. Under this confined transport mechanism, the problem of over-sized COF pores can be partially circumvented, and high selectivity obtained. Moreover, the obtained asymmetric configuration of SCOF-Ag/PI CMs results in directional gas transport. As the first work of COF-based membranes for olefin/paraffin separation, SCOF-Ag/PI CMs demonstrate a high propylene permeability of 75.16 barrer and good propylene/propane selectivity of 35.45, out-performing most of the polymer-based membranes and approaching the performance of ZIF-8 membranes. Furthermore, SCOF-Ag/PI CMs exhibit over one-month durability. The excellent separation performance combined with operating stability provides a promising alternative approach toward efficient C 3 H 6 /C 3 H 8 separation. [ABSTRACT FROM AUTHOR]

[Display omitted] • α-Fe 2 O 3 of cuboid/rhombohedral, spheroidal, rice-like, and plate-like were synthesised. • Photo-Fenton-like degradation of p-hydroxybenzoic acid (p-HBA) and sulfachloropyridazine (SCP) was conducted. • Correlation among atomic configuration of the exposed facets, specific surface area and photocatalytic activity was established. • Degradation mechanism and pathways for p-HBA and SCP were proposed. Hematite (α-Fe 2 O 3) with different shapes and preferentially exposed facets may differ in surface energy and atomic configuration resulting in versatile catalysis. Herein, four morphologies of α-Fe 2 O 3 nanocrystals, e.g. cuboid/rhombohedral, spheroid, rice-like, and plate-like are synthesised by hydrothermal/solvothermal routes. The correlation between morphology and photochemical performance is established by investigating the photo-Fenton-like degradation of p-hydroxybenzoic acid (p-HBA) and sulfachloropyridazine (SCP). The plate-like sample demonstrates the highest removal efficiency, whereas the normalised reaction rate by specific surface area shows the reaction order as cuboid/rhombohedral > plate-like > spheroid > rice-like. This can be ascribed to the synergistic role of the surface atomic arrangement and specific surface area. The main reactive species and degradation pathways were studied in detail. The research findings may offer new insights into the morphology/facet-dependent photochemical remediation of emerging contaminants (ECs) on α-Fe 2 O 3. [ABSTRACT FROM AUTHOR]

A novel porous sintered Ni metal as the matrix for supporting MoS 2 /Ni 3 S 2 hierarchical nanorods is successfully prepared by powder metallurgy and hydrothermal sulfurization. The porous sintered Ni-metal matrix supported with the MoS 2 /Ni 3 S 2 displays more advantages over Ni foam, including enhanced catalytic activity and stability, as well as the sufficient mechanical properties, which can be beneficial for the industrial service. [Display omitted] • The porous Ni metal substrate is fabricated via powder metallurgy. • The catalyst of MoS 2 /Ni 3 S 2 with hierarchical structures is confirmed. • The catalytic activity, conductivity and stability for HER are improved. • The self-supporting electrode exhibits sufficient mechanical properties. • NiO controlled by the annealing temperature determines the morphology. For the self-supporting catalysts of Hydrogen evolution reaction (HER), the rational design and fabrication of substrate with porous structure and sufficient mechanical strength are critical to promoting the industrial HER application. In this work, a novel porous sintered Ni metal as the matrix for supporting catalysts was successfully prepared by powder metallurgy, and a self-supporting electrode for HER was fabricated via a simple sulfurization process on this sintered Ni metal matrix. For instance, MoS 2 /Ni 3 S 2 nanorods (NRs) were vertically grown on the as-sintered porous Ni matrix, and the morphology of the sintered Ni matrix significantly affected the growth of MoS 2 /Ni 3 S 2 NRs. The NRs@Sintered Ni electrode shows a low overpotential of η10 = 56 mV and Tafel slope of 82 mV dec−1. Compared with NRs@Ni foam, the NRs@Sintered Ni exhibits superior stability, where no exfoliation and cracks are observed on the surface of the electrode after 5000 CV cycles. Ultra-high stability and long-term durability are obtained over 100 h even at high potentials of 200 and 300 mV. Moreover, the tensile strength of the as-obtained electrode based on the sintered Ni manifests nearly 260 times higher than that of NRs@Ni foam, evidencing an excellent mechanical property. This work provides an idea for the preparation of self-supporting metal-based catalytic electrodes in large-scale hydrogen production. [ABSTRACT FROM AUTHOR]

The review summarizes the typical synthetic strategies, morphologies, catalytic performances, mechanisms, application conditions and scope of various metallic matrices, such as Au, Mo, Ni, and Ti, for supporting TMCs catalysts. The development directions and outlook of self-supporting TMCs@Metal electrodes for large-scale preparation and catalytic water splitting in industrial applications are discussed in detail. [Display omitted] • The self-supporting catalytic electrodes for water splitting are studied. • The electrodes classified according to different substrates are summarized. • The loaded TMC materials and preparation strategies are discussed in detail. • The prospects of TMCs@Metal electrodes for industrial applications are suggested. Transition metal chalcogenides (TMCs) are the fascinating replacement of noble catalysts in catalytic water splitting due to their unique physical and chemical properties and low cost. However, their industrial application is substantially restricted by their poor conductivity. Decorating TMCs on metal substrates to fabricate self-supporting electrodes could be an efficient strategy for solving this problem. In this review, typical synthetic strategies for self-supporting TMCs on metal substrates are introduced in detail, while all types of metallic matrices, such as Au, Mo, Ni, Ti, Cu, etc., for supporting TMC catalysts are comprehensively summarized. By comparing the matrix types, types of loaded TMC materials, preparation strategies, application conditions, and scope, we attempt to establish rules of various metals as substrates, which may provide suggestions for material design. Finally, we briefly discuss the development directions of self-supporting TMCs@Metal electrodes for large-scale preparation and catalytic water splitting in industrial applications. [ABSTRACT FROM AUTHOR]

• Brittleness in polymer of intrinsic microporosity (PIM) membranes is alleviated by high molecular weight. • Role of micropores in developing water/ion conduction channels is investigated. • Microporous anion exchange membrane (AEM) has superior ion conduction efficiency. • H 2 crossover through microporous AEM is minimal in the hydrated state. • Feasibility of microporous AEMs for H 2 /O 2 fuel cell is evaluated. Polymers of intrinsic microporosity (PIMs) present an attractive opportunity for developing new types of anion exchange membranes (AEMs) for fuel cell featuring charged subnanometer-sized micropores. But challenges exist to make mechanically robust PIM AEMs due to their high chain rigidity. Imparting more flexibility improves mechanical properties but sacrifices microporosity. Here, a mechanically robust and highly anion conductive PIM AEM (QPIM-1) fabricated by facile animation and quaternization of PIM-1 membrane is reported, and its structure–property relationships are investigated, especially focusing on the microporous structure. High molecular weight alleviates brittleness, as QPIM-1 AEM shows comparable mechanical properties to conventional AEMs, quaternized poly(2,6-dimethyl-1,4-phenylene oxide) (QPPO), at a membrane thickness down to ~35 μm and a high ion exchange capacity (IEC) up to ~2.1 mmol g−1. The micropores situated among the rigid and contorted polymer chains evolve into water/ion conduction channels when the membrane is hydrated. This results in improved morphology over dense polymeric AEMs by less hindered ion pathways. QPIM-1 AEMs exhibit superior ion conduction efficiency, which is 2.6–5.3 times that of dense QPPO AEM at similar ion exchange capacities (IECs). A high hydroxide ion conductivity of 57 mS cm−1 at 20 °C is obtained, which is among the highest reported anion conductive PIM-based AEMs. Even though the AEMs are microporous, only slight H 2 permeation is observed when hydrated and at high open circuit voltage (OCV) of a single fuel cell. [ABSTRACT FROM AUTHOR]

[Display omitted] • Electrostatic-complexed fluorinated membranes (ECFMs) were fabricated. • Temporally-coordinated complexation regulates physicochemical structure of ECFMs. • ECFM shows high water flux of 93.3 L m−2 h−1 bar−1 and dye rejection over 90.0%. • Spatial and temporal antifouling property of ECFMs was evaluated and elucidated. • Optimized ECFM displays superior antifouling property and long-term stability. Membrane-based separation provides an energetically efficient and environmentally benign solution to water purification. Biomimetic self-assembled membranes affording full-aqueous-phase membrane fabrication built on underwater bioadhesion create a new paradigm to green and controllable membrane fabrication, but currently are obstructed by fouling and stability hurdles. Inspired by the chemical features of charged cement proteins of sandcastle worm, we propose an electrostatic-driven complexation method to fabricate fouling-resistant robust membranes. Phosphorylated polyanion, quaternized polycation and perfluorinated sulfonic acid polyanion are successively assembled onto the porous substrate to obtain electrostatic-complexed fluorinated membranes (ECFMs), where quaternized cellulose serves as a bridging polyelectrolyte to induce and coordinate electrostatic complexation. Temporal complexation generates 84-nm-thick membranes with precisely controlled physicochemical structure, surface energy and spatial interaction with foulants, harvesting ultrahigh water permeance of 93.3 L m−2 h−1 bar−1 with organic dyes (>450 Da) removal over 90.0%, and high fouling resistance ensuring persistently high production of purified water. Unlike the amino protein of traditional bio-cement whose positive charge strongly relies on pH, the environmentally-independent chargeability of quaternary ammonium and hydrophobic fluorine segment synergistically renders the membranes superior adaptability towards various underwater conditions for dozens or hundreds of days. [ABSTRACT FROM AUTHOR]

Based on the synergy between MoP and N-doped carbon, MoP nanoparticles encapsulated in N-doped carbon hollow spheres were synthesized using inorganic-organic hybrids as precursors, which shows an excellent stability and activity with an overpotential 96 mV at 10 mA cm−2 and a small Tafel slope of 53 mV dec−1 in alkaline solution. [Display omitted] • A template-free approach was developed to fabricate MoP@NC hollow microsphere. • Inorganic-organic hybrids were used as precursors. • Remarkable electrocatalytic hydrogen evolution performance could be achieved. • The synergy between MoP and the pyridinic N could optimize the electronic structure. Encapsulating transition metal phosphides into nitrogen-doped carbon (NC) materials is an effective strategy to enhance the electrocatalytic performance. Herein, we develop a novel template-free approach to rationally fabricate molybdenum phosphide (MoP) nanoparticles encapsulated in N-doped carbon (MoP@NC) hollow microspheres for alkaline hydrogen evolution reaction (HER) by employing inorganic-organic hybrids as precursors, in which phosphorus source of the MoP@NC derives from tetra (hydroxymethyl) phosphorus chloride for the first time. The optimized MoP@NC sample shows a low overpotential of 96 mV at 10 mA cm−2, a small Tafel slope of 53 mV dec−1, and excellent stability. The enhanced HER performance is mainly attributed to the integrated effects of a distinctive hollow structure, high pyridinic N-doping level, and the extremely intimate synergy between MoP and NC. Theoretical calculations indicate that the active sites of the catalyst are mainly located at Mo atoms adjacent to the pyridinic N-doped carbon layer (pyridinic-N-MoP); the synergistic interaction between MoP and pyridinic N (rather than pyrrolic or graphitic N) atoms can lower the d band center of Mo, weaken the Mo-H ads bond and thereby enhance HER performance. In addition, the pyridinic N atoms at the interactive sites play a key role in adsorbing H 2 O and preventing the adsorption of OH*, resulting in accelerating the water splitting. This work provides a new method to rationally synthesize high-efficient and stable MoP-based hollow sphere electrocatalysts for alkaline HER through designing inorganic-organic hybrid precursors. [ABSTRACT FROM AUTHOR]