Publications by authors named "Yunqing Kang"

High-entropy alloys (HEAs) have recently emerged as promising electrocatalysts for complex reactions owing to their tunable electronic structures and diverse, unique binding sites. However, their vast compositional space, in terms of both elemental variety and atomic ratios, presents a major challenge to the rational design of high-performance catalysts, as experimental efforts are often hindered by ambiguous element selection and inefficient trial-and-error methods. In this work, a bottom-up research strategy using machine learning-assisted first-principles calculations was applied to accelerate the design of quinary HEAs toward efficient multielectron transfer reactions.

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The selective detection of chlorinated aromatic hydrocarbons (CAHs) in environmental samples is challenging due to matrix interference effects. We report a surface-enhanced Raman spectroscopy (SERS) sensor that combines mesoporous Au films with UiO-66-I metal-organic framework (MOF) coatings to achieve the selective detection of CAHs. We show that mesoporous Au films can be considered hyperuniform two-dimensional (2D) materials where long-range correlations and local disorder assist in electromagnetic hotspot formation for SERS.

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Platinum (Pt)-based nanozymes display exceptional stability and catalytic activity in the activation of HO, making them ideal peroxidase (POD)-like substitutes for immunoassay applications. However, specific catalytic progress is hindered by the excessive orbital overlaps between Pt and oxygen-based intermediates. Herein, a highly efficient mesoporous medium-entropy alloy (m-MEA) nanozyme is reported to selectively enhance POD activity through synergy interaction of multiple elements.

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Designing 2D mesoporous metal-organic framework (MOF) nanosheets to overcome the limitations of bulk MOF counterparts, with a focus on enabling smooth mass transport, presents an attractive yet challenging endeavor. Here, a novel bottom-up interface-directed co-assembly method is presented for the synthesis of ultrathin 2D mesoporous UiO-66(Ce) nanosheets. The method utilizes an interface-directed co-assembly of amphiphilic perfluorooctanoic acid-induced lipid bilayers and spherical micelles from PS-b-PEO block copolymers to form unique 2D sandwich-like assemblies that guide the creation of 2D mesoporous UiO-66(Ce).

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Effective osteogenesis for bone regeneration is still considerably challenging for a porous β-tricalcium phosphate (β-TCP) scaffold to achieve. To overcome this challenge, hollow manganese dioxide (H-MnO) nanoparticles with an urchin-like shell structure were prepared and added in the porous β-TCP scaffold. A template-casting method was used to prepare the porous H-MnO/β-TCP scaffolds.

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Work function (WF) influences electron transport and intermediates adsorption, enabling charge balance and catalytic optimization for the hydrogen evolution reaction (HER). However, the understanding of the role of mesopores and the relationship between composition and WF in pristine Pt-based alloys remains lacking. Herein, various mesoporous binary Pt-M alloy films (m-Pt-M, M = Pd, Rh, and Ru) with uniform pores and elemental distributions are synthesized, providing an experimental platform to investigate this relationship.

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Trimetallic systems have garnered considerable attention in (electro)catalysis due to the synergistic effects resulting from the combination of three different metals. However, achieving precise control over the positioning of various metals and understanding the relationship between structure and performance remains challenging. This study introduces an approach for synthesizing Pd@Pt@Au mesoporous nanoparticles (MNPs) with distinct core-shell Pd@Pt structures, featuring well-dispersed isolated Au islands on the outer shell, improving the plasmonic effect.

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Electrochemical adsorption offers a promising approach for the separation of monovalent cations, which is an important but challenging subject in separation science. However, progress in this area has been hampered by the lack of suitable materials with effective ion selectivity. In this work, we present the synthesis of covalent organic frameworks (COFs) functionalized with a series of crown ethers (NCx-TAB-COFs, x donate 12, 15, 18, indicating the size of crown ether) for the efficient and highly selective electrochemical capture of monovalent cations.

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Electrochemical conversion has been regarded as an ideal technology for achieving clean and sustainable energy, showing significant promise in addressing the increasingly serious energy crisis and environmental pollution. Ru-containing electrocatalysts (RUCE) outperform other precious metals due to elevated intrinsic activity and superior cost-effectiveness, developing into a promising candidate for electrochemical conversion reactions. A significant challenge in the field of catalyst discovery lies in its heavy reliance on empirical methods, rather than approaches that are rooted in rational design principles.

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High-entropy alloys (HEAs) are promising materials for electrochemical energy applications due to their excellent catalytic performance and durability. However, the controlled synthesis of HEAs with a well-defined structure and a uniform composition distribution remains a challenge. Herein, a soft template-assisted electrodeposition technique is used to fabricate a mesoporous HEA (m-HEA) film with a uniform composition distribution of Pt, Pd, Rh, Ru, and Cu, providing a suitable platform for investigating structure-performance relationships.

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Perovskite oxides are considered highly promising candidates for oxygen evolution reaction (OER) catalysts due to their low cost and adaptable electronic structure. However, modulating the electronic structure of catalysts without altering their nanomorphology is crucial for understanding the structure-property relationship. In this study, a simple plasma bombardment strategy is developed to optimize the catalytic activity of perovskite oxides.

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Developing a reliable method for constructing mesoporous metal-organic frameworks (MOFs) with single-crystalline forms remains a challenging task despite numerous efforts. This study presents a solvent-mediated assembly method for fabricating zeolitic imidazolate framework (ZIF) single-crystal nanoparticles with a well-defined micro-mesoporous structure using polystyrene--poly(ethylene oxide) diblock copolymer micelles as a soft-template. The precise control of particle sizes, ranging from 85 to 1200 nm, is achieved by regulating nucleation and crystal growth rates while maintaining consistent pore diameters in mesoporous nanoparticles and a rhombohedral dodecahedron morphology.

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Atomically dispersed Pt-group metals are promising as nanocatalysts because of their unique geometric structures and ultrahigh atomic utilization. However, loading isolated Pt-group metals in single-atom alloys (SAAs) with distinctive bimetallic sites is challenging. In this study, we present amorphous mesoporous Ni boride (Ni-B) as an ideal substrate to uniformly disperse Pt atoms with tunable loadings (1.

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Article Synopsis
  • * This study introduces a new sensing platform that uses macroporous-mesoporous silver substrates with self-assembled polymeric micelles for simultaneous separation and analysis of multiple MP types through surface-enhanced Raman spectroscopy (SERS).
  • * A neural network algorithm, SpecATNet, is developed to analyze SERS data, effectively identifying six common types of MPs while handling complex mixtures and interferences, paving the way for field monitoring of microplastics.
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Ultrathin MXene-based films exhibit superior conductivity and high capacitance, showing promise as electrodes for flexible supercapacitors. This work describes a simple method to enhance the performance of MXene-based supercapacitors by expanding and stabilizing the interlayer space between MXene flakes while controlling the functional groups to improve the conductivity. TiCT MXene flakes are treated with bacterial cellulose (BC) and NaOH to form a composite MXene/BC (A-M/BC) electrode with a microporous interlayer and high surface area (62.

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Ammonia borane (AB) with 19.6 wt % H content is widely considered a safe and efficient medium for H storage and release. Co-based nanocatalysts present strong contenders for replacing precious metal-based catalysts in AB hydrolysis due to their high activity and cost-effectiveness.

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The production of vanillin from biomass offers a sustainable route for synthesizing daily-use chemicals. However, achieving sunlight-driven vanillin synthesis through HO activation in an aqueous environment poses challenges due to the high barrier of HO dissociation. In this study, we have successfully developed an efficient approach for gram-scale vanillin synthesis in an aqueous reaction, employing Mn-defected γ-MnO as a photocatalyst at room temperature.

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Rapid and efficient vascularization is still considerably challenging for a porous β-tricalcium phosphate (β-TCP) scaffold to achieve. To overcome this challenge, branched channels were created in the porous β-TCP scaffold by using 3D printing and a template-casting method to facilitate the instant flow of blood supply. Human bone mesenchymal stem cells (hBMSCs) and human umbilical vein endothelial cells (HUVECs) were seeded in the channeled porous scaffolds and characterized through a double-stranded DNA (dsDNA) assay, alkaline phosphatase (ALP) assay, and cell migration.

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The intrinsic roadblocks for designing promising Pt-based oxygen reduction reaction (ORR) catalysts emanate from the strong scaling relationship and activity-stability-cost trade-offs. Here, a carbon-supported Pt nanoparticle and a Mn single atom (Pt-Mn/C) as constructed Pt-Mn pairs are demonstrated to be an efficient catalyst to circumvent the above seesaws with only ∼4 wt % Pt loadings. Experimental and theoretical investigations suggest that Mn functions not only as the "assist" for Pt sites to cooperatively facilitate the dissociation of O due to the strong electronic polarization, affording the dissociative pathway with reduced HO production, but also as an electronic structure "modulator" to downshift the -band center of Pt sites, alleviating the overbinding of oxygen-containing intermediates.

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Developing innovative catalysts for efficiently activating O into singlet oxygen (O) is a cutting-edge field with the potential to revolutionize green chemical synthesis. Despite its potential, practical implementation remains a significant challenge. In this study, we design a series of nitrogen (N)-doped manganese oxides (N-MnO, where represents the molar amount of the N precursor used) nanocatalysts using compartmentalized-microemulsion crystallization followed by post-calcination.

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Efficient and durable electrocatalysts fabricated by using nanosized nonprecious-metal-based materials have attracted considerable attention for use in the oxygen evolution reaction (OER). Understanding performance disparities and structure-property relationships of various nonprecious-metal-based nanostructures is crucial for optimizing their applications. Herein, CoP nanoparticles encompassed within a CoFeP shell (named CoP/CoFeP) are fabricated.

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Composite polymer electrolytes (CPEs) with high ionic conductivity and favorable electrolyte/electrode interfacial compatibility are promising alternatives to liquid electrolytes. However, severe parasitic reactions in the Li/electrolyte interface and the air-unstable inorganic fillers have hindered their industrial applications. Herein, surface-edge opposite charged Laponite (LAP) multilayer particles with high air stability were grafted with imidazole ionic liquid (IL-TFSI) to enhance the thermal, mechanical, and electrochemical performances of polyethylene oxide (PEO)-based CPEs.

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Multimetallic alloys (MMAs) with various compositions enrich the materials library with increasing diversity and have received much attention in catalysis applications. However, precisely shaping MMAs in mesoporous nanostructures and mapping the distributions of multiple elements remain big challenge due to the different reduction kinetics of various metal precursors and the complexity of crystal growth. Here we design a one-pot wet-chemical reduction approach to synthesize core-shell motif PtPdRhRuCu mesoporous nanospheres (PtPdRhRuCu MMNs) using a diblock copolymer as the soft template.

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Controlling the synthesis of metal nanostructures is one approach for catalyst engineering and performance optimization in electrocatalysis. As an emerging class of unconventional electrocatalysts, two-dimensional (2D) metallene electrocatalysts with ultrathin sheet-like morphology have gained ever-growing attention and exhibited superior performance in electrocatalysis owing to their distinctive properties originating from structural anisotropy, rich surface chemistry, and efficient mass diffusion capability. Many significant advances in synthetic methods and electrocatalytic applications for 2D metallenes have been obtained in recent years.

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