Publications by authors named "Hongpan Rong"

The electrocatalytic reduction of nitrate (NO ) to ammonia (NH) holds substantial promise, as it transforms NO from polluted water into valuable NH. However, the reaction is limited by sluggish kinetics and low NH selectivity. Cu-based catalysts with unique electronic structures demonstrate rapid NO to NO rate-determining step (RDS) and fast electrocatalytic nitrate reduction reaction (eNORR) kinetics among non-noble metal catalysts.

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Developing efficient and earth-abundant catalysts for CO fixation to high value-added chemicals is meaningful but challenging. Styrene carbonate has great market value, but the cycloaddition of CO to styrene oxide is difficult due to the high steric hindrance and weak electron-withdrawing ability of the phenyl group. To utilize clean energy (such as optical energy) directly and effectively for CO value-added process, we introduce earth-abundant Ti single-atom into the mesoporous nitrogen, oxygen-doped carbon nanosheets (Ti-CNO) by a two-step method.

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Developing efficient and stable oxygen reduction reaction (ORR) catalysts to replace the precious Pt/C is very important for the industrial application of proton-exchange membrane fuel cells. Herein, using bismuth-based metal-organic frameworks as the substrate to disperse copper ions, we prepared a catalyst containing both Cu single atoms and Cu nanoparticles (CuCu/BiCN) by a pyrolysis method. In 0.

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Gadolinium chelates for tumor magnetic resonance imaging (MRI) face challenges such as inadequate sensitivity, lack of selectivity, and risk of Gd leakage. This study presents a single-atom Gd nano-contrast agent (Gd-SA) that enhances tumor MRI. Isolated Gd atoms coordinated by six N atoms and two O atoms are atomically dispersed on a hollow carbon nanosphere, allowing the maximum utilization of Gd atoms with reduced risk of toxic Gd ion leakage.

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Surface and strain engineering are two effective strategies to improve performance; however, synergetic controls of surface and strain effects remains a grand challenge. Herein, we report a highly efficient and stable electrocatalyst with defect-rich Pt atomic layers coating an ordered PtSn intermetallic core. Pt atomic layers enable the generation of 4.

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Dual-atom catalysts (DACs) are an important branch of single-atom catalysts (SACs), in which the former can effectively break the dilemma faced by the traditional SACs. The synergetic effects between bimetallic atoms provide many active sites, promising to improve catalytic performance and even catalyze more complex reactions. This paper reviews the recent research progresses of two kinds of DACs, including homonuclear and heteronuclear DACs, and their applications in oxygen reduction, carbon dioxide reduction, hydrogen evolution, oxygen evolution, Zn-air batteries, tandem catalytic reactions, and so on.

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Doping-related point defect engineering in low-dimensional semiconductor nanostructures is important to regulate their optical and electronic properties. The substitutional or interstitial location of heterovalent dopants is critical and has not been controlled effectively yet. Herein, we carefully control the kinetics of reverse cation exchange between CuS 2D nanosheets and ligand-coordinated Cd cations to control the Cu doping sites in CdS nanosheets (NSs).

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Single-atom catalysts (SACs) featuring the complete atomic utilization of metal, high-efficient catalytic activity, superior selectivity, and excellent stability have been emerged as a frontier in the catalytic field. Recently, increasing interests have been drawn to apply SACs in biomedical fields for enzyme-mimic catalysis and disease therapy. To fulfill the demand of precision and personalized medicine, precisely engineering the structure and active site toward atomic levels is a trend for nanomedicines, promoting the evolution of metal-based biomedical nanomaterials, particularly biocatalytic nanomaterials, from nanoparticles to clusters and now to SACs.

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We successfully fabricate a novel concave nanostructure that is composed of atomically dispersed Ru atoms in PtSn nanoconcaves (Ru-PtSn NCs), which shows enhanced performance in methanol electroxidation compared to commercial Pt/C. This could be ascribed to the stable intermetallic structure and active surface structure, as well as the synergy among Pt, Sn and Ru.

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Supported atomic clusters with uniform metal sites and definite low-nuclearity are intermediate states between single-atom catalysts (SACs) and nanoparticles in size. Benefiting from the presence of metal-metal bonds, supported atomic clusters can trigger synergistic effects among every metal atom, which contributes to achieving unique catalytic properties different from SACs and nanoparticles. However, the scalable and precise synthesis and atomic-level insights into the structure-properties relationship of supported atomic clusters is a great challenge.

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Here, the photocatalytic CO reduction reaction (CO RR) with the selectivity of carbon products up to 100% is realized by completely suppressing the H evolution reaction under visible light (λ > 420 nm) irradiation. To target this, plasmonic Au/CdSe dumbbell nanorods enhance light harvesting and produce a plasmon-enhanced charge-rich environment; peripheral Cu O provides rich active sites for CO reduction and suppresses the hydrogen generation to improve the selectivity of carbon products. The middle CdSe serves as a bridge to transfer the photocharges.

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The facet effect has been well demonstrated for nanocrystal catalysis, however it is rarely revealed in metal organic frameworks (MOFs). Herein, we present a facile way to construct 2D zeolitic imidazolate framework-67 (ZIF-67) with dominant exposure of the (002) facets. We discovered that the ZIF-67 (002) facet exhibited the highest catalytic activity for oxygen evolution reaction (OER) among the (002), (011), and (111) facets.

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Dilute alloy nanostructures have been demonstrated to possess distinct catalytic properties. Noble-metal-induced reduction is one effective synthesis strategy to construct dilute alloys and modify the catalytic performance of the host metal. Herein, we report the synthesis of ultrafine PtRu dilute alloy nanodendrites (PtRu NDs, molar ratio Ru/Pt is 1:199) by the reduction of Ru ions induced by Pt metal.

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The electrocatalytic reduction reaction of CO (CORR) is a promising strategy to promote the global carbon balance and combat global climate change. Herein, exclusive Bi-N sites on porous carbon networks can be achieved through thermal decomposition of a bismuth-based metal-organic framework (Bi-MOF) and dicyandiamide (DCD) for CORR. Interestingly, in situ environmental transmission electron microscopy (ETEM) analysis not only directly shows the reduction from Bi-MOF into Bi nanoparticles (NPs) but also exhibits subsequent atomization of Bi NPs assisted by the NH released from the decomposition of DCD.

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We experimentally determined the dispersion of the complex third-order nonlinear optical susceptibility χ of Au nanorods over a wide bandwidth (370 - 800 nm). Compared to bulk Au, these nanorods exhibit greatly enhanced nonlinearities that can be manipulated by geometrical parameters. Accurately measuring the χ values of nanostructured metals is challenging because χ is strongly influenced by the local field effects.

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Hollow-structured semiconductor nanocrystals (NCs) have aroused tremendous research interest because of their compelling structure-related properties that can facilitate the development of many important applications including solar water splitting. However, the creation of multicomponent semiconductor NCs (such as I-III-VI and I-II-IV-VI semiconductors) possessing a hollow architecture still remains a great challenge because of the difficulty in balancing the reactivities of multiple precursors. In this study, we report an effective strategy to prepare hollow CuInS nanododecahedrons featuring high uniformity in morphology and composition, based on the Kirkendall effect driven by the cation exchange between Cu and In using CuS nanododecahedrons as templates.

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The insertion of cation impurities into quantum dots (QDs) as a dopant has been proved to be an efficient way to tailor their optical, electronic, and magnetic properties; however, the low quantum yield (QY) and poor photostability strongly limit their further applications. We report a strategy to coat a thin oxide shell around the heterovalent doped QDs to enhance their QYs and photostabilities simultaneously. In the case of Ag-doped CdS QDs, the controlled cation exchange reaction between Cd and ternary AgSbS nanoparticles not only realizes the Ag doping in CdS QDs but also generates a thin SbO shell around the surface of the QDs.

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Promoting surface strains in heterogeneous catalysts and heteroatomic interactions in alloying offer an effective strategy for the development of electrocatalysts with greatly enhanced activity. In this work, we design platinum-silver nanotubes (PtAg NTs) with tunable surface compositions by a controlled galvanic replacement reaction of well-defined Ag nanowires (NWs). The optimized and porous PtAg NTs (PtAg-4 NTs), with the Pt5Ag3 surface composition and (111) facet-dominant surface features, exhibit an extraordinary oxygen reduction reaction (ORR) activity that reaches a specific activity of 1.

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Differently from the normal three single precursor method to produce colloidal ternary quantum dots (QDs), herein ternary Ag SbS quantum dots (QDs) with efficient near-infrared (NIR) luminescence have been prepared by a new facile in situ conversion of Ag nanocrystals (NCs) with a binary Sb/S organic precursor Sb(C H COOS) under low temperature. The unprecedented construction evolution from Ag NCs to Ag SbS /Ag hetero-structure and final monodisperse Ag SbS QDs has been demonstrated. These novel Ag SbS QDs exhibit efficient NIR emission at ≈1263 nm and possess high colloidal stability.

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Thiol- and solvent-coordinated cation exchange kinetics have been applied to engineer the composition and crystallinity of novel nanocrystals. The detailed thermodynamics and kinetics of the reactions were explored by NMR spectroscopy, time-dependent photoluminescence (PL) characterizations and theoretical simulations. The fine structure of the colloidal semiconductor nanocrystals (CSNCs) was investigated by X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS).

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Au@SnS and Au@SnS core-shell hybrid nanocrystals (HNCs) were respectively accessed via an aqueous cation exchange-mediated growth strategy by using different phosphine ligands. The choice of proper ligands during synthesis is imperative to optimize the photoelectrochemical performance of these previously hardly accessible HNCs that manifest compelling plasmon-exciton interactions.

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Focusing on ternary I-III-VI colloidal nanocrystals (NCs) synthesized with precise control of the composition (from doping to ternary composition) and NIR fluorescence performance, monodisperse binary In -doped Ag S NCs and ternary AgInS NCs have been achieved successfully by facile low-temperature in situ conversion of colloidal Ag S nanoparticles. In ions were inserted into the crystal lattice of Ag S NCs at a relatively low temperature as dopant and ternary AgInS NCs were obtained at a higher temperature following a phase transition. These doped Ag S and AgInS NCs based on different indium precursor concentrations were explored with respect to the position and intensity of the near-infrared photoluminescent emission at different doping levels and crystal phase evolution.

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We successfully obtained truncated octahedron PtAl alloy nanocrystals (∼10 nm) via a facile one-pot strategy. The PtAl nanocrystals exhibited enhanced activity in formic acid electrooxidation compared to commercial Pt/C, which could be ascribed to the large density of defects on the surface as well as the synergy between Pt and Al.

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The active species in supported metal catalysts are elusive to identify, and large quantities of inert species can cause significant waste. Herein, using a stoichiometrically precise synthetic method, we prepare atomically dispersed palladium-cerium oxide (Pd /CeO ) and hexapalladium cluster-cerium oxide (Pd /CeO ), as confirmed by spherical-aberration-corrected transmission electron microscopy and X-ray absorption fine structure spectroscopy. For aerobic alcohol oxidation, Pd /CeO shows extremely high catalytic activity with a TOF of 6739 h and satisfactory selectivity (almost 100 % for benzaldehyde), while Pd /CeO is inactive, indicating that the true active species are single Pd atoms.

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High-efficient charge and energy transfer between nanocrystals (NCs) in a bottom-up assembly are hard to achieve, resulting in an obstacle in application. Instead of the ligands exchange strategies, the advantage of a continuous laser is taken with optimal wavelength and power to irradiate the film-scale NCs superlattices at solid-liquid interfaces. Owing to the Au-based NCs' surface plasmon resonance (SPR) effect, the gentle laser irradiation leads the Au NCs or Au@CdS core/shell NCs to attach each other with controlled pattern at the interfaces between solid NCs phase and liquid ethanol/ethylene glycol.

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