Transfer Channels Research Articles

High-Performance H2 Photosynthesis from Pure Water over Ru-S Charge Transfer Channels.

As a versatile energy carrier, H2 is considered as one of the most promising sources of clean energy to tackle the current energy crisis and environmental concerns, which can be produced from photocatalytic water splitting. However, solar-driven photocatalytic H2 production from pure water in the absence of sacrificial reagents remains a great challenge. Herein, we demonstrate that the incorporation of Ru single atoms (SAs) into ZnIn2S4 (Ru-ZIS) can enhance the light absorption, reduce the energy barriers for water dissociation, and construct a channel (Ru-S) for separating photogenerated electron-hole pairs, as a result of a significantly enhanced photocatalytic water splitting process. Impressively, the productivity of H2 reaches 735.2 μmol g-1 h-1 under visible light irradiation in the absence of sacrificial agents. The apparent quantum efficiency (AQE) for H2 evolution reaches 7.5% at 420 nm, with a solar-to-hydrogen (STH) efficiency of 0.58%, which is much higher than the value of natural synthetic plants (∼0.10%). Moreover, Ru-ZIS exhibits steady productivity of H2 even after exposure to ambient conditions for 330 days. This work provides a unique strategy for constructing charge transfer channels to promote the separation of photogenerated electron-hole pairs, which may motivate the fundamental researches on catalyst design for photocatalysis and beyond.

Construction of CeO2/Co/CNT electrocatalyst with adsorption-catalytic synergistic effect for the suppression of the shuttle effect in lithium sulfur batteries

Lithium‑sulfur batteries are recognized as a strong candidate for the next generation of high capacity density batteries. However, the shuttle effect of soluble polysulfide intermediates during the charging and discharging process of lithium‑sulfur batteries leads to a rapid decrease in their electrochemical performance, thus limiting their practical applicability. In this study, the rare earth element cerium (Ce) was introduced into a bimetallic electrocatalyst to modify the separator in order to inhibit the shuttle effect for soluble polysulfide intermediates in lithium‑sulfur batteries. The CeO2/Co bimetallic electrocatalyst composite with in situ-grown carbon nanotubes (CeO2/Co/CNT) was obtained by a simple single-step high-temperature carbonization process. The strong polarity of CeO2 in CeO2/Co/CNT could trap soluble polysulfide intermediates onto the composite surface, synergizing with Co to further enhance the catalytic efficiency of soluble polysulfide intermediates into insoluble Li2S. Simultaneously, CNTs in CeO2/Co/CNT provided fast Li+ and electron transfer channels for the efficient catalytic conversion of soluble polysulfide intermediate. The initial discharge specific capacity of lithium‑sulfur batteries assembly by using CeO2/Co/CNT modified separator presented an initial discharge specific capacity of 1377.05 mAh g−1 at 0.1 C, and 676.8 mAh g−1 after 200 cycles at 1 C, demonstrating a significant performance improvement compared to blank control battery.

Thermal Enhanced Energy Transfer and High Thermal Sensitivity of Sb3+ Doped Cs2KYbCl6 Rare Earth Double Perovskites

AbstractRare‐earth based double perovskites (DPs) have attracted much attention due to stable, efficient, and unique luminescence, and wide applications in many optoelectronic fields. However, their weak near‐infrared (NIR) emission and poor anti‐thermal quenching severely limit the further applications. Herein, Sb3+‐doped Cs2KYbCl6 DP with cyan self‐trapped exciton (STE) and NIR emission is prepared by a solvothermal method, and the separate photoluminescence quantum yields from STE and NIR emission reached ≈26.1% and 43.8%, respectively. More importantly, Sb3+ not only contributes to the absorption and energy transfer but also helps to establish an effective thermally enhanced energy transfer channel through self‐trapping state, resulting in the NIR emission with superior anti‐thermal quenching resistance. The thermal sensitivity of luminescence intensity ratio (LIR) of I1010 nm/I505 nm (I is the intensity of PL) and time‐resolved temperature sensor reach 21.4 and 13.6% K−1, respectively, which are ahead of most temperature sensing materials. Furthermore, it is found that the material exhibited advanced multifunctional applications in LED lighting, flexible luminescent thin film, and NIR imaging. This work provides in‐depth understanding on photophysical mechanisms of rare‐earth luminescent materials and references for designing high‐performance materials.

In situ coordinated ultrathin MOF-polymer electrolyte membrane with vertically aligned transfer channels for solid lithium metal batteries

Metal organic framework (MOF)-polymer composite solid electrolyte membrane with novel microstructure is expected to show attractive prospect for solid state lithium metal batteries. But the reported MOF were usually regarded as an entirety in composite solid electrolyte resulting in tradeoff between ionic conductivity and lithium dendrite inhibition ability. Herein, MOF-polymer composite membrane with vertically aligned channels and ultrathin MOF layer is proposed to decrease lithium ion transportation resistance obtained by simple phase inversion and in situ coordinated growth methods. The vertically aligned highways can decrease tortuous pathways and intensify ion conduction. The embedded ultrathin MOF layer on membrane surface leads to homogeneous plating/stripping of lithium. This novel structured MOF-polymer composite solid electrolyte exhibits improved ionic conductivity of 0.55 mS cm−1 at 22 ° C and lithium ion transference number of 0.87. Furthermore, the Li/Li symmetrical cell shows stable lithium plating/stripping performance for 1100 h at 0.1 mA cm−2 and 0.1 mA h cm−2. LiFePO4/MOF-polymer/Li coin battery demonstrates good rate capability and cycling performance with capacity retention of 82 % after 100 cycles at 0.2C and the pouch cell can light up the “DLUT” blue light lamp under folding and cutting states. This work encourages a new avenue to develop composite solid electrolytes with ion transportation highways and uniform distribution plane for solid lithium metal batteries.

Charge engineering in black phosphorene with tunable electronic structures as efficient oxygen evolution electrocatalyst

The unique electronic structure of layered black phosphorus (BP) makes it an ideal candidate material for electrocatalytic oxygen evolution reaction (OER). Charge doping effectively improves the environmental stability and catalytic activity of BP by providing electron transfer channels and reducing charge transfer barrier. Therefore, based on the first principles calculation, this paper theoretically discusses how the intrinsic charge doping without introducing impurities changes the electronic structure and improves the catalytic activity of BP. It is found that charge engineering can effectively regulate and change the electronic structure and work function by stimulating the hybridization between different P-p orbitals, while maintaining the direct bandgap semiconductor characteristics of monolayer BP system. More importantly, in the catalytic process of OER, electrons and hole doping as free charges provide different donor and acceptor energy levels for the system depending on the doping concentration, and affect the adsorption capacity of monolayer BP to different reaction intermediates. At a certain doping concentration, the carrier mobility increases significantly, and the optimal Gibbs free energy and overpotential can be achieved in monolayer BP. These results provide new opportunities and possibilities for designing charge-engineered BP catalysts with adjustable electronic structure and excellent OER activity.

Iron Sulfide Microspheres Supported on Cellulose-Carbon Nanotube Conductive Flexible Film as an Electrode Material for Aqueous-Based Symmetric Supercapacitors with High Voltage.

Nanostructured iron disulfide (FeS2) was uniformly deposited on regenerated cellulose (RC) and oxidized carbon nanotube (CNT)-based composite films using a simple chemical bath deposition method to form RC/CNT/FeS2 composite films. The RC/CNT composite film served as an ideal substrate for the homogeneous deposition of FeS2 microspheres due to its unique porous architecture, large specific surface area, and high conductivity. Polypyrrole (PPy), a conductive polymer, was coated on the RC/CNT/FeS2 composite to improve its conductivity and cycling stability. Due to the synergistic effect of FeS2 with high redox activity and PPy with high stability and conductivity, the RC/CNT/FeS2/PPy composite electrode exhibited excellent electrochemical performance. The RC/CNT/0.3FeS2/PPy-60 composite electrode tested with Na2SO4 aqueous electrolyte could achieve an excellent areal capacitance of 6543.8 mF cm-2 at a current density of 1 mA cm-2. The electrode retained 91.1% of its original capacitance after 10,000 charge/discharge cycles. Scanning electron microscopy (SEM) images showed that the ion transfer channels with a pore diameter of 5-30 μm were formed in the RC/CNT/0.3FeS2/PPy-60 film after a 10,000 cycle test. A symmetrical supercapacitor device composed of two identical pieces of RC/CNT/0.3FeS2/PPy-60 composite electrodes provided a high areal capacitance of 1280 mF cm-2, a maximum energy density of 329 μWh cm-2, a maximum power density of 24.9 mW cm-2, and 86.2% of capacitance retention after 10,000 cycles at 40 mA cm-2 when tested at a wide voltage window of 1.4 V. These results demonstrate the greatest potential of RC/CNT/FeS2/PPy composite electrodes for the fabrication of high-performance symmetric supercapacitors with high operating voltages.

Multiple resonance delayed fluorescence emitter with C3 symmetry for high-performance solution-processed OLEDs

Solution-processed organic materials that exhibit both high emission efficiency and narrowband emission characteristics are rare, and the performance of corresponding solution-processed organic light-emitting diodes (sOLEDs) remains inadequate for practical applications. This study proposes a proof-of-concept design aimed at enhancing both solution processing capability and emission efficiency in multiple-resonance induced thermally activated delayed fluorescence (MR-TADF) materials through the integration of multiple emitting units. A unique emitter named TriBNCz is synthesized and characterized, incorporating three MR-building blocks onto a single phenyl ring, resulting in sky-blue emission with a peak at 490 nm and a small full width at half maximum (FWHM) of 25 nm. Significant improvements in solution processing attributes, including solubility and film-forming properties, are achieved. Moreover, except for the MR effect of the excited states, long-range charge transfer properties of excited states are also obtained. The multiple charge transfer channels contribute to higher rate of reverse intersystem crossing (kRISC). The optimized sOLED device exhibits a maximum external quantum efficiency (EQEmax) of 17.8 %. Furthermore, by employing 5TCzBN as a sensitizer, the sensitized sOLED achieves an EQEmax of 28.8 % and a high-level EQE of 26.1 % at 1000 cd m−2, with an FWHM of 30 nm and Commission Internationale de I’Éclairage (CIE) coordinates of (0.103, 0.497), representing one of the best results among narrowband emission sOLEDs. This research opens a new avenue to develop high-performance solution-processed organic materials and sOLED devices.

The slopes of sub-barrier heavy-ion fusion excitation functions shed light on the dynamics of quantum tunnelling

Quantum tunnelling plays a crucial role in heavy-ion fusion reactions at sub-barrier energies, especially in the context of nuclear physics and astrophysics. The nuclear structure of the colliding nuclei and nucleon transfer processes represent intrinsic degrees of freedom. They are coupled to the relative ion motion and, in general, increase the probability of tunnelling. The influence of couplings to nucleon transfer channels relatively to inelastic excitations, on heavy-ion fusion cross sections, is one of the still open problems in this field. We present a new analysis of several systems, based on the combined observation of the energy-weighted excitation functions Eσ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$E\\sigma $$\\end{document} in relation to their first energy derivatives d(Eσ)/dE\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$d(E\\sigma )/dE$$\\end{document}. The relation between d(Eσ)/dE\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$d(E\\sigma )/dE$$\\end{document} and Eσ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$E\\sigma $$\\end{document} removes the basic differences due to the varying Coulomb barrier when comparing different systems. We show that, depending on the nuclear structure and/or the presence of strong transfer channels, this representation reveals characteristic features below the barrier. The possible presence of cross section oscillations makes this analysis less clear for light- or medium-light systems.

Circumventing bottlenecks in H2O2 photosynthesis over carbon nitride with iodine redox chemistry and electric field effects

Artificial photosynthesis using carbon nitride (g-C3N4) holds a great promise for sustainable and cost-effective H2O2 production, but the high carrier recombination rate impedes its efficiency. To tackle this challenge, we propose an innovative method involving multispecies iodine mediators (I−/I3−) intercalation through a pre-photo-oxidation process using potassium iodide (suspected deteriorated “KI”) within the g-C3N4 framework. Moreover, we introduce an external electric field by incorporating cationic methyl viologen ions to establish an auxiliary electron transfer channel. Such a unique design drastically improves the separation of photo-generated carriers, achieving an impressive H2O2 production rate of 46.40 mmol g−1 h−1 under visible light irradiation, surpassing the most visible-light H2O2-producing systems. Combining various advanced characterization techniques elucidates the inner photocatalytic mechanism, and the application potential of this photocatalytic system is validated with various simulation scenarios. This work presents a significative strategy for preparing and applying highly efficient g-C3N4-based catalysts in photochemical H2O2 production.

In situ semi-etching of bimetallic LDH nanosheet arrays into FeNi-LDH/MOF to boost oxygen evolution reaction

The inherent sluggish kinetics of water oxidation is the core issue for electrochemical hydrogen production from water splitting. Metal organic frameworks (MOFs) with tunable porous structures, abundant coordination metal centers and large specific surface area are expected as efficient electrocatalysts. In this paper, FeNi-LDH/MOF composite nanostructures were successfully constructed on carbon cloth (CC) through partially converting iron-nickel layered double hydroxide (FeNi-LDH) into FeNi-MOF (NiFe(CN)5NO) by an in-situ semi-etching method. The MOF nanocrystals in this material are in-situ decorated on the surface of FeNi-LDH nanosheets, providing abundant open active sites and mass transfer channels for electrocatalysis. Thanks to the synergistic effect of the LDH and MOF, as well as the exceptional hierarchical architecture, the FeNi-LDH/MOF/CC as a self-supported electrode exhibits distinguished electrocatalytic OER performance, with a low overpotential of 263 mV@100 mA cm−2 and a small Tafel slope of 50.2 mV dec-1 in 1.0 M KOH. In addition, the catalyst exhibits good durability with almost constant current density during 24 h OER test. This work provides an effective way to design high-performance MOFs-based composite electrocatalytic materials.

Biomimetic designing MOFs nanosheet based membranes with self-recovery two-dimensional selective channels for specific molecules long-lasting precise separation

Two-dimensional (2D) materials-based membranes with artificial transfer channels have shown significant potential for selective separation. However, the challenges such as uncontrollable interlayer spacing and undesirable molecular sieving capabilities of 2D channels have impeded their further application in separation. Inspired by biological selectivity transport channels with proper steric and affinity sites, herein we have designed biomimetic 2D selective transport channels based on a ZIF-L nanosheet membrane. In this design, the UiO-66-NH2 nanoparticles tune the appropriate interlayer confinement and compensate for laminate framework defects of 2D selectivity transport channels, the artificial imprinting recognition sites establishes the essential chemical environment for specific separation. As a result, the obtained MOFs nanosheet based membranes with imprinted recognition sites (MN-IMs) exhibited enhanced permeation flux (J = 1.0847 × 10−3 and 1.0423 × 10−3 mg min−1 cm−2) and permselectivity (α = 3.77 and 4.10), outperforming state-of-the-art similar technologies. Besides, the composite MOFs demonstrated good photoinduced self-recovery ability, which also enables MN-IMs to have long-lasting selective separation performance (the separation efficiency is 90.76 %) in the continuous separation process. This study introduces a novel design strategy for developing sophisticated 2D materials-based membranes and offers new insights into the precise separation of specific molecules.

Mesopore-rich La-based metal organic framework derivatives for phosphorus removal from mariculture tailwater

Deep dephosphorization of mariculture tailwater, a typical high-salinity and weakly alkaline wastewater, is difficult but essential for meeting ever-stricter stringent emission standards. Herein, we developed an alkaline-conversion method to prepare lanthanum-based metal organic framework (La–MOF) derivatives for efficient phosphate removal from mariculture tailwater. During the templated alkaline-conversion process, the strong-alkaline regent gradually broke the coordination bonds of La–MOF while maintained its macrostructure, and the La nodes liberated from the framework were then crystallized into La(OH)3. The universality of this conversion method was verified on other La–MOF precursors with different benzoic multicarboxylate ligands. Importantly, numerous mesopores were formed in the derivative interior, increasing the number of exposed active La sites and accessible transfer channels. Therefore, the derivative exhibited superior phosphate-adsorption performance with a high adsorption capacity (Langmuir Q0: 155.7 mg P/g) and a rapid adsorption rate. The obtained La–MOF derivative with stable structure had broad neutral–alkaline pH range adaptability, which was demonstrated satisfactory dephosphorization selectivity and high cyclic performance under different seawater conditions (coexisting anions, cations, H3BO3 and natural organic matter). Finally, the obtained mesopore-rich La–MOF derivative exhibited an excellent deep dephosphorization capacity for actual mariculture tailwaters collected from seven mariculture ponds. The reactive phosphate level was quickly reduced to an ultra-low effluent concentration (<0.05 mg P/L), demonstrating the promising application potential of the La–MOF derivative.

NiCoMn-LDH with core-shell heterostructures based on CoS nanotube arrays containing multiple ion diffusion channels for boosted supercapacitor applications

Nanostructure engineering and composition rationalization are crucial for materials to become candidates for high-performance supercapacitor. Herein, a novel core-shell heterostructured electrode, combining CoS hollow nanorods with NiCoMn-layered double hydroxides (LDH) ternary metal nanosheets, were prepared on carbon cloth by reasonably controlled vulcanization and electrodeposition. By optimizing electrodeposition conditions, the material's structure and properties can be fine-tuned. The enhanced capacitance of the optimized carbon cloth (CC)@CoS/NiCoMn-LDH-300 electrode (4256.0 F g−1) lies in the open space provided by CoS and the establishment of a new charge transfer channel across the interfaces of CC@CoS/NiCoMn-LDH-300 nanosheets. This is further demonstrated by Density functional theory (DFT) simulations based on OH− adsorption energy, which produces faster redox charge kinetics and significantly enhances the electrode's energy storage capacity. The hybrid supercapacitor, integrating the optimized CC@CoS/NiCoMn-LDH-300 electrode with active carbon, demonstrates the highest energy density of 86 Wh kg−1 (under the power density of 850 W kg−1) and the long cycle stability of 89.7%. This study aims to go beyond simple binary LDH by constructing a ternary LDH with a hierarchical core-shell heterostructure to provide an effective and feasible new concept for high-performance supercapacitor electrode materials via rational structure design.

Engineering the luminescence and photothermal properties of metal complex Ruphen functionalized with silver nanoparticles for infrared human detection

A luminescence quenching enhanced infrared (IR) detector has been developed to achieve highly sensitive recognition of human body by adding metallic luminescence quenchers. Spherical Ag NPs were mixed with Ru(phen)32+ complex to obtain temperature-sensitive Ag/Ruphen/PVDF films. The relationships among luminescence output, temperature rise and silver addition were investigated and a satisfactory combination of enhanced luminescence factor and temperature change was found with an addition of 5 mol% of 71 nm Ag NPs. It is found that the metal-enhanced luminescence output is insignificant compared to its thermal ingredient since silver provides additional possible electron transfer channels, promoting non-radiative transitions and weakening luminescence. Besides, the Ag NPs induced additional temperature rise bringing further reduction of luminescence. The photothermal effect of Ag NPs can attain a higher temperature change under a certain IR radiation without an observed degradation of luminescence output. A coupled optical-thermal model was established to explain the schematic of the constructed infrared thermal detector. The non-invasive detections of moving and stationary human by the detector were successfully demonstrated. The work tends to provide an engineered optical-thermal model in luminophores and construct highly sensitive luminescence-based infrared thermal detectors.

Rational construction of defective Z-Scheme tandem heterojunction interfacial charge transfer channels for efficient uranium collection and resistance to biological contamination

Designing an efficient reduction of soluble U(VI) to insoluble U(IV) is a challenge, and efficient electron-hole transfer efficiency is the key to the conversion of U(VI) to U(IV). Herein, defective transition metal sulfide (Ov-ZAF) Z-Scheme tandem heterojunctions with spatial separation were synthesized using an in situ self-assembly method. Ov-ZAF has excellent electron-hole separation, stabilized reactive active sites, and excellent visible light absorption. Ov-ZAF is able to realize the photocatalytic U(VI) reduction reaction (URR) and water oxidation reaction (WOR) synergistically. The results showed that Ov-ZAF was able to reduce 498.3 mg/g of U(VI) in 100 ppm uranium solution for 200 min, with a reduction efficiency of 99.8 %. Ov-ZAF showed excellent reduction ability in a variety of uranium-containing waste solutions as well as in real seawater. In addition, Ov-ZAF is capable of generating reactive oxygen radials (ROS) and has excellent antimicrobial activity against Escherichia coli, Staphylococcus aureus and Pseudoalteromonas xiamen. Oxygen vacancies and tandem components can tune both occupied and unoccupied orbitals near the Fermi level of Ov-ZAF. This work provides a possibility of efficient uranium reduction engineering through tunable compositions and electronic structures.

Dendrite-free, long cycle life Zn–MnO2 battery based on a polyanionic hydrogel electrolyte by constructing transfer channels and regulating solvation structure

Aqueous zinc ion batteries (AZIBs) are highly regarded as new generation of energy storage devices because of low cost and environmental friendliness. Particularly, flexible AZIBs with hydrogel electrolytes are suitable candidates for wearable electronics. However, continuous water-induced side reactions, uncontrolled dendrites and trade-off of electrochemical performances with mechanical strength are still obstacles for high-performance AZIBs. To address these issues, we designed a polyanionic hydrogel electrolyte (PAPHE) with sulfonate monomers and polyethylene glycol diacrylate (PEGDA) as crosslinker. Due to the electrostatic interactions between Zn2+ and sulfonate ions, Zn2+ can migrate along polyanionic chains. Meanwhile, electronegative oxygen atoms in PEGDA also interact with Zn2+ and weaken electrostatic interactions. The transfer channels are formed with “wall” of polyanion chains and PEGDA. Moreover, both sulfonate ions and ether bonds on the “wall” can regulate the solvation structure to reduce the activity of water, inhibiting side reactions, corrosion or by-products. Therefore, the PAPHE shows satisfying conductivity of 16.38 mS cm−1, stable Zn plating/stripping over 1600 h, flexibility and high compressive resistance (0.501 MPa at strain of 50 %). The Zn||PAPHE||MnO2 cells deliver good specific capacity of 274.5 mAh g−1 and can cycle over 1800 times. The pouch-cell can also work stably under various deformations.

A Ni-doped coral-like three-dimensional Mo2C nanorod for sensitive electrochemical monitoring of environmentally polluting nitrobenzene

This paper reports the synthesis of a Ni-doped coral-like three-dimensional Mo2C nanorod via the pyrolysis of polypyrrole (PPy)-loaded NiMoO4·xH2O nanorods for nitrobenzene (NB) detection. The incorporation of Ni species into Mo2C enhances dual-atom synergistic catalysis, while the inclusion of PPy as a preferred carbon source improves the composite's active area. The coral-like three-dimensional rod structure not only provides various types of sites for adsorbing reactants but also offers more channels for ion migration and electron transfer, promoting charge transfer and further enhancing its electrical conductivity. The resulting composite demonstrates a wide linear detection range (2.11–1053.61 μM), high sensitivity, low limit of detection (0.64 μM, S/N = 3), and excellent stability and anti-interference performance in NB detection. This novel composite preparation approach offers promising prospects for practical NB detection applications.

Simultaneously enhancing toluene adsorption and regeneration process by hierarchical pore in activated coke: a combined experimental and adsorption kinetic modeling study.

Activated coke is a type of commonly used adsorbent for benzene series VOCs such as toluene, but traditional microporous activated coke usually faces the challenge of poor regeneration performance. Herein, based on self-made activated cokes with typical pore configuration, we found that adsorption and regeneration of toluene can be simultaneously enhanced by constructing hierarchical pore in activated coke. Correlations of pore configuration with toluene adsorption capacity and regeneration efficiency reveal that micropore contributes for strong toluene adsorption; meso-macropore provides mass transfer channel for toluene desorption and regeneration process. Hierarchical porous activated coke prepared from Zhundong subbituminous coal not only achieves the highest toluene adsorption capacity of 340.92mg·g-1, but also can retain more than 90% of initial adsorption capacity after five adsorption-regeneration cycles. By contrast, micropore-dominant activated cokes can only retain 70% of initial adsorption capacity. Adsorption kinetic modelling on adsorption breakthrough curves shows that hierarchical porous activated coke prepared from Zhundong subbituminous coal exhibits high adsorption and diffusion rate constants of 14.39 and 33.45min-1, respectively, much higher than those of micropore-dominant activated cokes. Due to the accelerated surface adsorption and diffusion processes induced by meso-macropore, toluene adsorption and regeneration behavior can be simultaneously improved. Results from this work validated the role of pore hierarchy in toluene adsorption-regeneration process, providing guidance for designing high-performance activated coke with synergistically improved toluene adsorption capacity and regeneration performance.

Enhanced Femtosecond Nonlinear Optical Susceptibility and Terahertz Conductivity in MoSe2‐Noble Metal Nanocomposites

AbstractCreating heterojunctions or composites by incorporating noble metals offers a remarkable means to modulate the electronic charge transfer and the nonlinear optical (NLO) properties in 2D transition metal dichalcogenides (TMDCs). The response of such 2D‐TMDC‐noble metal composites to femtosecond (fs) infrared (IR) and terahertz (THz) radiation, however, remains vastly unexplored. While the linear optical characteristics of a prototypical 2D‐TMDC, namely, MoSe2 nanosheets incorporated with noble metal (such as Au, Pt, and Ag) nanoparticles in the UV–Vis and the THz spectral range, the NLO characteristics are measured using a 70‐fs pulse at 800 nm excitation is investigated. The results demonstrate a clear reduction of band gap with the incorporation of noble metals in MoSe2, indicating an effective charge transfer mechanism at play. Notably, the MoSe2‐noble metal nanocomposites depicted a significant enhancement in the THz conductivities. In addition, a dramatic 4‐fold enhancement in the third‐order nonlinear coefficient and ≈2‐fold enhancement in the third‐order NLO susceptibility is achieved in MoSe2‐Ag nanocomposite. These results univocally suggest that the noble metal‐based composites with suitable charge transfer channels promote enhanced carrier mobilities and tunable electron transfer dynamics, making these hybrid materials promising candidates for optoelectronic applications both at IR and THz frequencies.

NiFeCo alloy nanoparticles composited with phosphorus-doped vacancies-abundant carbon substrates as electrocatalyst for oxygen evolution reaction

Transition metal alloy nanoparticles are cost-effective electrocatalysts for oxygen evolution reactions. Preparing alloy catalysts with flexible controllability, high activity, and long-term stability is a challenge. By adjusting the proportion of metal atoms and engineering vacancies through their composite with a carbon substrate, we can enhance electron transfer and modulate the adsorption capacity of reaction intermediates. Herein, we synthesized a hybrid catalyst using Prussian blue analogs (PBAs) as the precursor, doped with Fe and Ni atoms, and subjected them to a defective engineering and phosphatization process. As an efficient alkaline OER electrocatalyst, the formation of the alloy increases the number of active sites, while the defect-rich phosphorus-doped carbon substrate improves internal electron transfer and mass transfer channels. The synthesized NiFeCoPC-1.5 electrocatalyst exhibits excellent catalytic activity with an overpotential of 211 mV at 10 mA cm−2 and a Tafel slope of 59 mV dec−1, and demonstrates good stability up to 1000 CV cycles. This work will expand the application of alloy nanoparticles in oxygen evolution electrodes.