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Facile synthesis of FeNi alloy-supported N -doped Mo 2 C hollow nanospheres for enhanced oxygen evolution reaction. [Display omitted] • Facile synthesis of FeNi alloy-supported N -doped Mo 2 C hollow nanospheres. • FeNi/Mo 2 C/NC supports strongly accelerated electron transfer, thereby improving the OER kinetics. • FeNi/Mo 2 C/NC hybrids will hold promise in development of electrode materials. The rapid depletion of fossil fuels results in significant environmental pollution. Consequently, researching environmentally friendly and cost-effective electrocatalysts with exceptional oxygen evolution reaction (OER) capabilities holds immense importance in enhancing the efficient utilization of resources. In this paper, a straightforward and cost-effective method was employed to produce Fe-Ni alloy-supported N -doped carbon hollow nanospheres (FeNi/Mo 2 C/NC) using self-assembled molybdenum dopamine spheres (Mo-PDA-HS) as a substrate. The inclusion of iron and nickel addressed the issue of aggregation and collapse in Mo-PDA-HS nanostructures at high temperatures, while adjusting the electronic structure of the composites to achieve efficient OER activity. The composite displayed a low overpotential (η10 mA = 304 mV) and a minimal Tafel slope (41.8 mV/dec-1). This study introduces a simple strategy for constructing structurally robust and non-aggregating Mo 2 C nanostructures, along with a direct method for designing cost-effective and high-performance catalysts for OER. [ABSTRACT FROM AUTHOR]

In this paper, Fe-N 3 S 1 and FeS sub-nano cluster are innovatively connected to S, N co-doped carbon matrix (SNC) by controlled calcination process. The local electron configuration of Fe center is modulated by this unique structure. Based on this design, Fe-N 3 S 1 and FeS sub-nano cluster shown excellent synergistic effects in oxygen reduction reaction. The optimized ORR activity was obtained. [Display omitted] Single atomic Fe-N 4 catalyst exhibits a great prospect for oxygen reduction reaction (ORR) and adjusting the intrinsic coordination structure and the carbon matrix structure effectively improves the catalytic activity. However, controlling the active site coordination structure and its surrounding environment at atomic level remains a challenge. In this paper, Fe-N 3 S 1 and FeS sub-nano cluster were innovatively concatenated on S, N co-doped carbon matrix (SNC), denoted as FeS/FeSA@SNC catalysts, for modulating ORR catalysis performance. Both experimental measurements and theoretical calculations have confirmed that the local electron configuration of Fe center is modulated by this unique structure combination leading to optimized ORR kinetics. Based on this design, the synthesized FeS/FeSA@SNC delivers ORR activity with a half-wave potential of 0.9 V (vs. RHE), excelling that of commercial Pt/C (0.87 V) and the Zn-air battery (ZAB) with this cathode catalyst delivers a peak power density of 126 mW cm−2. This work presents a novel strategy for manipulating the single-atom active sites through control the local coordination structure and provides a reference for the development of novel efficient ORR electrocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] Solar energy conversion into hydrogen (H 2) energy has attracted much attention. However, the low light utilization rate and fast carrier recombination of photocatalysts extremely limit the practical application of photocatalytic H 2 production. In this paper, MoSe 2 -NiSe with abundant active sites and interfacial electronic structures as dual co-catalysts were assembled on g-C 3 N 4 nanosheets (NSs) vis a solvothermal reaction process. MoSe 2 -NiSe/g-C 3 N 4 NSs composite exhibited improved light absorption and photoelectrochemical properties. The photocatalytic H 2 production rate of MoSe 2 -NiSe/g-C 3 N 4 composite achieved 2379.04 μmol·h−1·g−1, which is 99.25, 1.44, and 3.67 times those of pure g-C 3 N 4 nanosheets (23.97 μmol·h−1·g−1), MoSe 2 /C 3 N 4 (1654.57 μmol·h−1·g−1), and NiSe/C 3 N 4 (649.08 μmol·h−1·g−1), respectively. The apparent quantum efficiency (AQE) value of MoSe 2 -NiSe/g-C 3 N 4 achieved 4.07 % under light at λ = 370 nm. The corresponding characterization and experiments proved that 2D ultrathin g-C 3 N 4 NSs with a large surface area and short charge-transfer distance could facilitate light scattering and the transport of photoexcited electrons. MoSe 2 -NiSe, as a dual co-catalyst, showed strong electronic synergistic interaction between the interfaces, thus improving the conductivity and promoting the electron transfer process. [ABSTRACT FROM AUTHOR]

[Display omitted] • The porous few-layer bimetallic co-doped g-C 3 N 4 is prepared via a facile bottom-up method. • The bimetallic synergetic regulating effect on the electronic structure can be produced in Co/Ni-g-C 3 N 4. • The superior performance results from the improved charge separation efficiency and visible light harvestability. • This work provides meritorious guidance for new bimetallic co-doped g-C 3 N 4 photocatalysts. The low specific surface area and low charge transfer efficiency of conventional graphite carbon nitride (g-C 3 N 4) are the main obstacles to its application in photocatalytic CO 2 reduction. In this paper, graphite carbon nitride was protonated by phosphoric acid (H 3 PO 4), and a new few-layer porous carbon nitride was prepared by intercalation polymerization with doping bimetal in the cavity of g-C 3 N 4. Under visible light irradiation, the CO formation rate of Co/Ni co-doped g-C 3 N 4 can reach 13.55 μmol g−1 h−1, which was 3.9 times higher than that of g-C 3 N 4 (3.49 μmol g−1 h−1). The density functional theory (DFT) calculations showed that the addition of Co and Ni in the cavity of g-C 3 N 4 can induce bimetallic synergistic regulation of the electronic structure, thus improving the separation efficiency of charges and visible light capture ability of g-C 3 N 4. Our work has great reference value for designing and synthesizing novel bimetallic co-doped g-C 3 N 4 photocatalytic materials. [ABSTRACT FROM AUTHOR]

[Display omitted] As a promising dopant, electron deficient B atom not only tunes the electronic structure of electrocatalysts for improving their intrinsic catalytic activities, but also combines with hydroxy radical as strong adsorption sites for accelerating the water dissociation during the hydrogen evolution reaction (HER). In this paper, we report an electrocatalyst based on boron-modified Ru anchored on carbon nanotubes (B-Ru@CNT) that shows impressive HER activity in acidic and alkaline media. The boron-rich closo -[B 12 H 12 ]2- borane was selected as a moderately strong reductant for the in situ reduction of a Ru salt, which yielded B-doped Ru nanoparticles. The experimental and theoretical results indicate that the incorporation of B not only weakens the Ru-H bond and downshifts the d-bond centre of Ru from the Fermi level by reducing the electron density at Ru but also accelerates the water dissociation reaction by providing B sites, which strongly adsorb OH* intermediates, and nearby Ru sites, which act as sites for the adsorption of the H* intermediate, thus boosting the HER performance and enhancing the HER kinetics. As a result of the tuning of the electronic structure via B doping, B-Ru@CNT showed excellent HER performance, yielding overpotentials of 17 and 62 mV at a current density of 10 mA cm−2 in alkaline and acidic solutions, respectively. These results indicate that our synthetic method is a promising route to B-doped metallic Ru with enhanced pH-independent HER performance. [ABSTRACT FROM AUTHOR]

[Display omitted] Defect engineering is an important strategy to regulate electronic structure of electrocatalysts for electrochemical N 2 fixation, aiming at improving the electron state density and enhancing the adsorption and activation of inert N 2. In this paper, a high-temperature strategy to anneal the natural molybdenite under Ar atmosphere was developed, and the as-obtained molybdenite with S vacancies boosted a high activity for N 2 reduction reaction. In 0.1 M HCl, the catalyst annealed at 800 °C exhibits a high Faradic efficiency of 17.9% and a NH 3 yield of 23.38 μg h−1 mg-1 cat. at −0.35 V versus reversible hydrogen electrode, two times higher than that of the pristine molybdenite. The facile one-step annealing method introduces the defects (e.g., S vacancies) in the surface of the natural molybdenite particles to prepare catalysts for generating ammonia by reducing nitrogen at room temperature under ordinary pressure, promoting the development of low-carbon economic prospect. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) graphitic carbon nitride (g-C 3 N 4) nanoplates (CNNP) have become a hot research topic in photocatalysis due to their small thickness and large specific surface area that favors charge transport and catalytic surface reactions. However, the wide application of 2D g-C 3 N 4 nanoplates prepared by ordinary methods suffers from increased band gaps with a poor solar harvesting capability caused by the strong quantum confinement effect and reduced conjugation distance. In this paper, a facile approach of exfoliation and the following fast thermal treatment of the bulk g-C 3 N 4 is proposed to obtain a porous few-layered g-C 3 N 4 with nitrogen defects. Due to the preferable crystal, textural, optical and electronic structures, the as-obtained porous CNNP demonstrated a significantly improved photocatalytic activity towards water splitting than the bulk g-C 3 N 4 and even the 3 nm-thick CNNP obtained by sugar-assisted exfoliation of the bulk g-C 3 N 4. The difference in the enhancement factors between the H 2 O splitting and organic decomposition has revealed the effect of N defects. This study offers insightful outlooks on the scalable fabrication of a porous few-layered structure with a promoted photocatalytic performance. [ABSTRACT FROM AUTHOR]

In this paper, the carbon-doped boron nitride nanoplate (C-BNNP) was prepared by pyrolyzing the precursor under N 2 and served as an excellent adsorbent for removal of Rhodamine B (RhB). The structure and composition of C-BNNP were characterized and its adsorption behavior for RhB was investigated. Compared with boron nitride nanoplate (BNNP) which was synthesized under NH 3 , C-BNNP displayed an enhancement of the adsorption capacity for RhB (833 mg/g). The adsorption activity was comprehensibly studied by kinetics, isotherm and thermodynamics. The adsorption kinetics followed pseudo-second-order model. The equilibrium adsorption data agreed well with the Langmuir isotherm. And the thermodynamics indicated that the adsorption process was a spontaneous, exothermic and physisorption process. In addition, the density functional theory was proposed that doping carbon in the BNNP decreased the chemical hardness of the adsorbent and enhanced the adsorption capacity of C-BNNP for RhB. [ABSTRACT FROM AUTHOR]

Abstract: The passage of swift heavy ions through dielectric layers (SiO2 or SiON) on silicon, creates ion tracks in them. After the etching and filling of these ion tracks with a suitable material, a novel electronic structure acronymed TEMPOS – ‘Tunable Electronic Materials with Pores in Oxide on Silicon’ has been realized. Several electronic devices, both, active and passive, have been fabricated and systematically studied in the last few years. Sensors have also been successfully made and characterized using the TEMPOS structure as it offers a high surface to volume ratio resulting in fast response time and high sensitivity of the sensor. In continuation with these studies, in the present paper, ferrofluids have been inserted in the ion tracks to study their behaviour in confined geometry and for subsequently obtaining magnetic sensors. A comparative study has been done between the aqueous and non-aqueous ferrofluids. Insertion of the ferrofluids in the ion tracks exhibits a change in the I–V behaviour in the presence of a magnetic field which can be exploited for obtaining the above said sensor. [ABSTRACT FROM AUTHOR]