Organic-inorganic Hybridization Research Articles

Lightweight, Elastic, and Superhydrophobic Multifunctional Organic-Inorganic Fibrous Aerogels for Efficient Oily Wastewater Purification and Electromagnetic Microwave Absorption.

Lightweight and robust aerogels with multifunctionality are highly desirable to meet the technological demands of current society. Herein, we designed lightweight, elastic, and superhydrophobic multifunctional organic-inorganic fibrous hybrid aerogels which were assembled with organic aramid nanofibers and inorganic hierarchical porous carbon fibers. Thanks to the organic-inorganic fiber hybridization strategy, the optimal aerogels possessed remarkable compressibility and elasticity. Benefiting from the microscopic hierarchical porous structure of carbon fibers and the macroscopic macroporous lamellar structure of aerogels, the optimal aerogels exhibited superb lightweight property, conspicuous electromagnetic microwave absorption ability, and outstanding oily wastewater purification capacity. As for electromagnetic microwave absorption, it achieved a strong reflection loss of -41.8 dB, and the effective absorption bandwidth reached 6.86 GHz. Besides, the oil adsorption capacity for trichloromethane reached as high as 93.167 g g-1 with a capacity retention of 95.6% after 5 cycles. Meanwhile, it could act as a gravity-driven separation membrane to continuously separate trichloromethane from a trichloromethane-water mixture with a high flux of 7867.37 L·m-2·h-1, even for surfactant-stabilized water-in-n-heptane emulsions of 3794.94 L·m-2·h-1. Such a strategy might shed some light on the construction of multifunctional aerogels toward broader applications.

Construction of a hybrid flame retardant based on mesoporous silica for enhancing fire safety, smoke suppression, and mechanical properties of epoxy resins

AbstractIn order to improve the fire safety of epoxy resins (EPs), the SBA‐15 based hybrid flame retardant (SNAZD) was synthesized via an organic–inorganic hybridization strategy of mesoporous silica SBA‐15. Relying on electrostatic interaction, the zinc amino‐tris‐(methylenephosphonate) (Zn‐ATMP) was successfully introduced into the pore channels of SBA‐15. Then, 9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO) was successfully loaded into the pores of SBA‐15 under vacuum. The results show that the EP composites with the 5%SNAZD sample (sample EP‐5%SNAZD) showed a LOI value of 30.9% and achieved the vertical burning V‐0 rating. In comparison to EP, the peak heat release rate, peak smoke production rate, and production rate of CO of EP‐3%SNAZD were reduced by 32.2%, 31.9%, and 20.0%, respectively. This is due to the presence of Si, P, N, and Zn elements in the SNAZD, which promoted the generation of a high yield of dense char residue and inhibited the release of toxic gasses. And the impact strength and flexural strength of EP‐1%SNAZD were increased by 19.5% and 15.6%, respectively, and the E' of EP‐5%SNAZD increased by 49.1% when compared with the neat EP. This work provides a general strategy for the design of mesoporous hybrid flame retardant and creates additional opportunities for applications of EP.

Rational Combination of π-Conjugated and Non-π-Conjugated Groups Achieving Strong Nonlinear Optical Response, Large Optical Anisotropy, and UV Light-Switchable Fluorescence.

Combining π-conjugated and non-π-conjugated groups is an important strategy for synthesizing new nonlinear optical (NLO) crystals. However, the second harmonic generation (SHG) response and optical anisotropy can be limited by improper spatial alignment of these functional groups in the crystal structure. In this work, it is revealed that non-π-conjugated [NH2SO3] group acts as both hydrogen bond donor and acceptor, effectively regulating the 2D planar structure formed by π-conjugated [C4N3H6] groups. The resulting organic-inorganic hybrid crystal C4N3H6SO3NH2 exhibits a strong SHG response (2.5 × KDP), large optical anisotropy (0.233@546nm), and blue-violet and green fluorescence near 360 and 520nm, respectively. This work expands the methodology for creating new NLO crystals through organic-inorganic hybridization, while also showcasing the potential of C4N3H6SO3NH2 as a multifunctional optical material.

C(NH2)3]6Mo7O24: A Guanidinium Molybdate as a UV Nonlinear Optical Crystal with Large Birefringence.

The key to searching novel nonlinear optical (NLO) crystals was effectively combining the NLO-active units to obtain a noncentrosymmetric structure. Nevertheless, the present predicament lies in the growing challenge of discovering novel crystals within conventional inorganic frameworks that surpass the properties of the current NLO materials. In view of this, researchers expanded their research focus to the organic-inorganic hybridization system; it is foreseeable to concentrate the advantages from several kinds of NLO-active units to acquire novel NLO crystals with superior properties. We herein report an organic-inorganic hybrid molybdate crystal, namely, [C(NH2)3]6Mo7O24 (GMO). It was successfully obtained via combining inorganic NLO-active MoO6 octahedra and organic π-conjugated [C(NH2)3]+ groups. GMO demonstrates a moderate second-harmonic-generation response, specifically measuring about 1.3 times the value of KDP. Additionally, it exhibits a significant birefringence value of 0.203 at the wavelength of 550 nm and possesses a wide band gap of 3.31 eV. Theoretical calculations suggest that the optical properties of the GMO are primarily influenced by the synergy effect of [C(NH2)3]+ groups between MoO6 octahedra.

Organic-inorganic hybridization strategy for promoting BiOBr CO2 photoreduction via enhanced CO2 adsorption and photogenerated carrier migration

The low electron-hole separation efficiency and poor CO2 adsorption of BiOBr limit its photoreduction CO2 performance. In this work, BiOBr was hybridized with Ni-MOF, it shows that the Eads of BiOBr decreases from −0.36 eV to −1.73 eV, and the Gibbs free energy of CO2 adsorption decreases from 0.12 eV to −1.25 eV. In addition, the PL and TPR results reveal that the hybridization strategy accelerates the electron-hole separation rates. The CO evolution of BiOBr/Ni-MOF is 121.8 μmol g−1 h−1 when the amount of Ni-MOF is 15%, which is 5 and 7.2 times higher than BiOBr and Ni-MOF, respectively. Briefly, the CO2 adsorption and photogenerated carrier separation of inorganic materials can be improved by organic–inorganic hybridization strategy, which inspires a new direction for the design of high-performance catalysts.

Zn-Shik-PEG nanoparticles alleviate inflammation and multi-organ damage in sepsis

Sepsis is defined as a life-threatening organ dysfunction caused by excessive formation of reactive oxygen species (ROS) and dysregulated inflammatory response. Previous studies have reported that shikonin (Shik) possess prominent anti-inflammatory and antioxidant effects and holds promise as a potential therapeutic drug for sepsis. However, the poor water solubility and the relatively high toxicity of shikonin hamper its clinical application. To address this challenge, we constructed Zn2+-shikonin nanoparticles, hereafter Zn-Shik-PEG NPs, based on an organic-inorganic hybridization strategy of metal-polyphenol coordination to improve the aqueous solubility and biosafety of shikonin. Mechanistic studies suggest that Zn-Shik-PEG NPs could effectively clear intracellular ROS via regulating the Nrf2/HO-1 pathway, meanwhile Zn-Shik-PEG NPs could inhibit NLRP3 inflammasome-mediated activation of inflammation and apoptosis by regulating the AMPK/SIRT1 pathway. As a result, the Zn-Shik-PEG NPs demonstrated excellent therapeutic efficacies in lipopolysaccharide (LPS) as well as cecal ligation puncture (CLP) induced sepsis model. These findings suggest that Zn-Shik-PEG NPs may have therapeutic potential for the treatment of other ROS-associated and inflammatory diseases.

Organic Excitonic State Management by Surface Metallic Coupling of Inorganic Lanthanide Nanocrystals

AbstractThe ability to harness charges and spins for control of organic excitonic states is critical in developing high‐performance organic luminophores and optoelectronic devices. Here we report a facile strategy to efficiently manipulate the electronic energy states of various organic phosphors by coupling them with inorganic lanthanide nanocrystals. We show that the metallic atoms exposed on the nanocrystal surface can introduce strong coupling effects to 9‐(4‐ethoxy‐6‐phenyl‐1,3,5‐triazin‐2‐yl)‐9H‐carbazole (OCzT) and some organic chromophores with carbazole functional groups when the organics are approaching the nanocrystals. This unconventional organic–inorganic hybridization enables a nearly 100 % conversion of the singlet excitation to fast charge transfer luminescence that does not exist in pristine organics, which broadens the utility of organic phosphors in hybrid systems.

Organic Excitonic State Management by Surface Metallic Coupling of Inorganic Lanthanide Nanocrystals.

The ability to harness charges and spins for control of organic excitonic states is critical in developing high-performance organic luminophores and optoelectronic devices. Here we report a facile strategy to efficiently manipulate the electronic energy states of various organic phosphors by coupling them with inorganic lanthanide nanocrystals. We show that the metallic atoms exposed on the nanocrystal surface can introduce strong coupling effects to 9-(4-ethoxy-6-phenyl-1,3,5-triazin-2-yl)-9H-carbazole (OCzT) and some organic chromophores with carbazole functional groups when the organics are approaching the nanocrystals. This unconventional organic-inorganic hybridization enables a nearly 100 % conversion of the singlet excitation to fast charge transfer luminescence that does not exist in pristine organics, which broadens the utility of organic phosphors in hybrid systems.

Investigating the adhesion and rheological properties of metal organic framework incorporated polyester fiber/zeolite imidazolium salt framework‐67‐modified asphalt composite

AbstractUtilizing efficient and cost‐effective modifiers is essential for the development of high‐performance asphalt materials. In this study, a polydopamine (PDA) chelated cobalt ion (Co2+)‐assisted in situ growth strategy was employed to anchor nanoporous zeolite imidazolium salt framework‐67 (ZIF‐67) on polyester (PET) fiber substrates for the preparation of styrene‐butadiene‐styrene block copolymer‐modified asphalt (SBS‐MA). Experimental results indicated that optimal fiber incorporation of 1.5% led to the best interfacial interaction at the modified asphalt fracture section. ZIF‐67 nanoporous structure acted as an organic–inorganic hybridization interfacial layer to enhance the fiber–asphalt interfacial interaction. The adhesion work of the modified fiber with SBS‐MA increased by 42.12%. Furthermore, the adhesion work, peeling work, and compatibility ratio of modified asphalt with aggregates were also improved. Similarly, the complex modulus of the 1.5% ZIF‐67–PDA–PET/SBS‐MA at 46°C was increased by 131.30% in comparison with that of the pristine SBS‐MA. More importantly, the synergistic effect of the highly thermally stable PET fibers and ZIF‐67 nanocrystals improved the thermal decomposition of SBS‐MA. These results suggest that ZIF‐67–PDA–PET fiber holds great promise for application in designing novel materials for the construction industry.

In Situ Formation of Coordinated Polymer via Organic–Inorganic Hybridization Engineering Boosting High‐Efficiency Potassium Storage

AbstractOrganic redox‐active molecules with merits of structure diversity and tunable properties are emerging as promising cathodes for the practical usage of potassium‐ion batteries (PIBs). However, the inferior cycle stability and sluggish charge‐carrier mobility are two main drawbacks hindering the practical application of organic cathode materials. Herein, highly conductive inorganic CuS is combined with small molecule‐based redox species (perylene‐3,4,9,10‐tetracarboxylic dianhydride, PTCDA) to form a novel organic–inorganic hybrid cathode (PTCDA/CuS) for PIBs, which could undergo electrochemical‐induced in situ self‐transformation of a sulfur‐linked and Cu2+‐coordinated PTCDA polymer (labeled as Cu@PTCDA‐SP). Benefiting from improved redox sites from activated carbonyl groups, high stability afforded by the sulfur‐bridging, isotropic amorphous nature, and 3D cross‐linked nanosheet morphologies, the resulting Cu@PTCDA‐SP cathode exhibits a high‐rate capacity involving trielectron enolization (vs 2‐electron transformation in PTCDA monomers) and long‐term cycle life (over 2800 cycles at 5 A g−1). This organic–inorganic hybridized cathode is very promising for PIBs. Additionally, the self‐transformation strategy provides new insight into the discovery of more electrochemically induced interaction between organic–inorganic hybrids toward high‐performance secondary batteries.

Effect of organosilicone on the reaction process of functionalized geopolymers

We have recently synthesized a novel alkylated-geopolymer (AGP) with superior water and corrosion resistance based on organic-inorganic hybridization technique, which is desirable for various applications in building engineering. In this work, the impact of sodium methyl siliconate (SMS), which serves as a vital organic component, on the reaction process of metakaolin-based geopolymers was investigated. The research focused on the underlying mechanisms by evaluating the variation of properties including the apparent viscosity, reaction heat, mechanical strength, chemical composition, and microstructure. The results reveal that initial AGP pastes cured for 1 d exhibit higher strength and reactivity compared to the OGP paste. Organosilicon monomers demonstrate greater competitiveness than [Al(OH)4] monomers in forming initial alkylated sodium aluminosilicate hydrate (A-NASH) gels, thereby enhancing the early-age reaction of the AGP paste. In contrast, the strength and polymerization degree of final AGP pastes cured for over 7 d are relatively lower, indicating educed susceptibility of A-NASH gels to rearrangement and reorganization, which correlates with the number of the binding site of the [H3C–Si(OH)3] unit. These findings provide valuable insights for synthesizing organic-inorganic hybrids and offer guidance for the practical application of AGP materials in engineering contexts.

Poly(dimethyl-diphenyl-imide)siloxane/phenolic-based double network hybrid resin coatings for ablation thermal protection

Organic-inorganic hybridization is an important way to improve ablation resistance of phenolic resin coatings (PR). However, long molecular chain silicone by copolymerization is less compatible with PR and hybrid resin will form sea-island phase, which is not favorable for further improvement of ablation resistance. Therefore, how to achieve a combination of long chain and compatibility is a major challenge. In this work, the poly(dimethyl-diphenyl-imide)siloxane (PMPI) containing imide and phenyl was synthesized by anionic ring-opening polymerization and copolymerization. Then, it was hybridized with PR to obtain PMPI/PR-based double network hybrid resin coatings with nano co-continuous phase. The oxyacetylene ablation test suggests that the resin coatings with medium phenyl content has the lowest linear ablation rate (0.055 mm/s), which is 74 % lower compared to PR (0.21 mm/s). In addition, the mechanism by which PMPI enhances ablation resistance is discussed. This work provides a promising approach to develop higher performance ablative-resistant resin coatings.

Aqueous green synthesis of organic/inorganic nanohybrids with an unprecedented synergistic mechanism for enhanced near-infrared photothermal performance.

Silver sulfide (Ag2S) nanoparticles (NPs) represent one of the most popular inorganic reagents for near-infrared (NIR) photothermal therapy (PTT). However, the extensive biomedical applications of Ag2S NPs are greatly compromised by the hydrophobicity of the NPs prepared in organic solvents, their low photothermal conversion efficiency, certain surface modification-induced damage to their intrinsic properties and short circulation time. To develop a facile yet efficient green approach to overcome these shortcomings for improved properties and performance of Ag2S NPs, we report herein the construction of Ag2S@polydopamine (PDA) nanohybrids via a "one-pot" organic-inorganic hybridization strategy, which produces uniform Ag2S@PDA nanohybrids with well-modulated sizes in the range of 100-300 nm via the self-polymerization of dopamine (DA) and subsequent synergistic assembly of PDA with Ag2S NPs in a three-phase mixed medium containing water, ethanol and trimethylbenzene (TMB). Integration of dual photothermal moieties, i.e., Ag2S and PDA at a molecular level, endows Ag2S@PDA nanohybrids with synergistically enhanced NIR photothermal properties that are much better than those of either PDA or Ag2S NPs due to calculated combination indexes (CIs) of 0.3-0.7 between Ag2S NPs and PDA based on a modified Chou-Talalay method. Therefore, this study not only developed a facile "one-pot" green approach toward producing uniform Ag2S@PDA nanohybrids with well-modulated dimensions, but also revealed an unprecedented synergistic mechanism for organic/inorganic nanohybrids that is based on dual photothermal moieties providing enhanced near-infrared photothermal performance.

Energy-saving-lamp-driven photodegradation of pyroquilon and admire in the presence of cucurbituril-block composite of g-C3N4/Ag3PO4@Q[7

A novel supramolecular photocatalyst with the macrocyclic compound of cucurbit [7]uril (Q [7]) block, g-C3N4/Ag3PO4@Q [7] composite, is successfully prepared by ternary organic-inorganic hybridization. The material is applied for the photo-driven degradation of the pesticides pyroquilon and admire in the irradiation of visible light. The results revealed a high degradation efficiency is achieved in 300 min exposure, and the decomposition of 93.9% for pyroquilon and 96.8% for admire is produced with the reaction rates of 9.3 × 10−3 min−1 and 1.2 × 10−2 min−1, respectively. The comprehensive understandings are realized with the proposed degradation pathway and the built photoelectron transfer mechanism. The photocatalyst exhibits a high stability and reusability, the degradation efficiencies are afforded as 74% for pyroquilon and 86% for admire in five catalytic cycles. Comparing with the reported photocatalysts, the developed material offered performance advantages of low energy consumption and fast reaction rates in the degradation of pyroquilon and admire pesticides.

Improving coating and prepressing performance of soy protein-based adhesive by constructing a dual-bionic topological structure

Developing efficient and sustainable green adhesives to replace aldehyde-based adhesives has become an important strategy to address fossil resources depletion, environmental pollution, and clean production. Soy protein is a raw material-rich, renewable biomass material that can be used to prepare environmental-friendly adhesives. However, the weak interfacial adhesion of soy protein-based (SP) adhesives leads to poor coating and prepressing properties, thus limiting the large-scale application of the SP adhesives. In this study, a bionic "bond-stitch" molecular topology was designed and constructed in SP matrix to prepare a strong multifunctional adhesive. Inspiring by the strong adhesion of mussel, urushiol (U) with natural catechol structure and acrylamide were polymerized in situ into poly(urushiol-co-acrylamide) (PUAM) as stitching polymer, which was entangled with the SP network to form a bond-stitch molecular topology. The hydroxyapatite was used to construct an organic-inorganic hybridization in the SP matrix mimicking the tough cohesion of oysters. The resultant dual-bionic SP adhesive exhibited excellent coating performance, prepressing intensity (0.45 MPa), flame retardancy (the limiting oxygen index was 39.4%), mildew resistance (10 d), low volatile organic compounds release, and good antibacterial activity (the antibacterial rates against Escherichia coli, Staphylococcus aureus, and Candida albicans were 89.55%, 78.59%, and 99.91%, respectively.). The wet shear strength of the prepared SP adhesive was increased from 0.35 MPa to 1.17 MPa. This study provides a new strategy for the design and preparation of high-performance, sustainable, low-carbon footprint bio-adhesives and composites.

Methylene blue intercalated vanadium oxide with synergistic energy storage mechanism for highly efficient aqueous zinc ion batteries

With the rise of aqueous multivalent rechargeable batteries, inorganic-organic hybrid cathodes have attracted more and more attention due to the complement of each other's advantages. Herein, a strategy of designing hybrid cathode is adopted for high efficient aqueous zinc-ion batteries (AZIBs). Methylene blue (MB) intercalated vanadium oxide (HVO-MB) was synthesized through sol–gel and ion exchange method. Compared with other organic–inorganic intercalation cathode, not only can the MB intercalation enlarge the HVO interlayer spacing to improve ion mobility, but also provide coordination reactions with the Zn2+ to enhance the intrinsic electrochemical reaction kinetics of the hybrid electrode. As a key component for the cathode of AZIBs, HVO-MB contributes a specific capacity of 418 mA h g−1 at 0.1 A g−1, high rate capability (243 mA h g−1 at 5 A g−1) and extraordinary stability (88% of capacity retention after 2 000 cycles at a high current density of 5 A g−1) in 3 M Zn(CF3SO3)2 aqueous electrolyte. The electrochemical kinetics reveals HVO-MB characterized with large pseudocapacitance charge storage behavior due to the fast ion migration provided by the coordination reaction and expanded interlayer distance. Furthermore, a mixed energy storage mechanism involving Zn2+ insertion and coordination reaction is confirmed by various ex-situ characterization. Thus, this work opens up a new path for constructing the high performance cathode of AZIBs through organic-inorganic hybridization.

(Invited) Vapor-Phase Infiltration for Microelectronics Applications

Vapor-phase infiltration (VPI) is an emerging organic-inorganic materials hybridization technique derived from atomic layer deposition (ALD) wherein gaseous organometallic precursors and co-reactants diffuse into starting organic templates in a sequential and cyclic manner and become hybridized with the organic matrix. The resulting hybrids feature uniquely enhanced materials properties, including but not limited to mechanical, chemical, dielectric, optical, and electrical properties, which are controllable by the type and amount of infiltrated inorganic species. When combined with polymer templates with either dimensional confinement (e.g., lithographically defined polymer patterns) or intrinsic spatial chemical contrast (e.g., self-assembled block copolymer (BCP) thin films), the technique also yields a site-specific infiltration, analogous to area-selective ALD, creating a spatially localized hybridization. Furthermore, the organic matrix of such infiltrated hybrids can be selectively removed by plasma ashing and thermal annealing to generate inorganic nanostructures that inherit the morphology of starting polymer templates, providing an alternative inorganic nanopatterning methodology. In this talk, I will showcase how these features of VPI can be utilized for the applications in microelectronics, including: (a) arbitrary patterning ultrahigh aspect-ratio metal oxide nanostructures; (b) generation of metal-oxide-based nanowire and nanomesh structures for conductometric sensing; and (c) VPI-derived metal-oxide-infiltrated hybrid photoresists for extreme ultraviolet (EUV) lithography.

Nondestructive x-ray reflectivity analysis of Al distributions of ultraviolet-cured spin-coated resist films hybridized with trimethylaluminum

Ultraviolet (UV)-cured spin-coated resist films of 100 nm and thinner thicknesses made with bisphenol A-based dimethacrylate monomers on silicon substrates were hybridized by multiple-pulsed vapor infiltration of sequential trimethylaluminum (TMA) doses and a final H2O dose. Nondestructive x-ray reflectivity measurements without film shrinkage enabled characterization of the internal layer structures of the UV-cured films unmodified before hybridization and hybridized by TMA infiltration and chemical fixing. It was possible to determine the thickness, density, and interface roughness of each layer in the unmodified and hybridized UV-cured films. The TMA infiltration and chemical fixing resulted in the formation of the highest-density Al-rich layer near the film surface. The presence of the highest-density layer arising from the most abundant component, Al, was confirmed through energy-dispersive x-ray spectroscopy and time-of-flight secondary ion mass spectrometry. The increase in the cycle number of TMA dose from 100 to 150 and 200 cycles had little effect on organic–inorganic hybridization of the 100 nm-thick UV-cured films. The thickness of the outermost Al-rich layer near the film surface was approximately 30 nm, which was unchanged when the film thicknesses of 100, 75, and 50 nm were changed. The outermost skin layer suppressed the infiltration of TMA into the UV-cured films. The infiltration of TMA into the UV-cured films progressed as the film thicknesses decreased.

Photoelectrochemical reduction of nitrate to ammonia over CuPc/CeO2 heterostructure: Understanding the synergistic effect between oxygen vacancies and Ce sites

• CuPc/CeO 2 with rich OVs has been successfully fabricated for PEC NO 3 – reduction. • CuPc/CeO 2 exhibited the NH 3 production rate up to 1.16 μmol h -1 m −2 . • Thermodynamic and kinetic factors of PEC NRR have been synergistically optimized. • The isotope NMR result further confirmed the accuracy of NO 3 – → NH 3 conversion. Photoelectrochemical nitrate (NO 3 – ) reduction reaction (PEC NRR) is a promising technology to solve both environmental pollution and traditional energy crisis. However, the fabrication of efficient catalyst with controllable active sites for high selectivity is still challenging. In this work, copper phthalocyanine (C 32 H 16 CuN 8 )/cerium dioxide (CuPc/CeO 2 ) heterostructure has been designed as a model to understand the role of Ce 3+ /Ce 4+ pairs on the formation of oxygen vacancies (OVs), which helps for identifying the key factors to adjust the chemical adsorption and activation of NO 3 – in PEC NRR system. Furthermore, the unique organic–inorganic hybrid matrix significantly strengthens the relationship of solar harvest–carriers’ separation–NO 3 – reduction. CuPc/CeO 2 heterostructure exhibits a high NH 3 yield of 1.16 μmol h −1 cm −2 and Faradic efficiency of 33% (-0.6 V vs.), and the desirable PEC NRR could be well retained for 5 cycles. Therefore, the construction of CuPc/CeO 2 successfully optimizes the thermodynamic and kinetic factors in PEC NRR system, providing a new insight for organic–inorganic hybridization and NH 3 green production.

Impacts of Metal-Support Interaction on Hydrogen Evolution Reaction of Cobalt-Nitride-Carbide Catalyst.

Cobalt-nitride-carbide (Co-N-C) catalysts are promising cost-efficient transition metal catalysts for electrocatalytic hydrogen evolution, but few works investigate the metal–support interaction (MSI) effect on hydrogen evolution reaction (HER) performance. Herein, efficient Co-N-CX catalysts with controllable MSI between encapsulated Co nanoparticles and nitrogen-doped graphitic carbon nanosheets were synthesized via a facile organic–inorganic hybridization method. Results demonstrate that the Co-N-C0.025M catalyst with the coexistence of single-atom Co sites and Co nanoparticles prepared by 0.025 M cobalt nitrate shows excellent HER performance, achieving a low overpotential of 145 mV to reach 10 mA cm−2 in 0.5 M sulfuric acid, which is mainly because the optimal MSI, which leads to a moderate hydrogen adsorption energy and improved electroactive sites, not only facilitates the charge transfer to improve the HER kinetics, but also improves the durability of the catalyst by Co-N bond anchoring and encapsulation of active Co species. This work provides guidance to further reveal the influence of MSI on their catalytic activity.