Doping Engineering Research Articles

Ru doping and interface engineering synergistically boost the electrocatalytic performance of a WP/WP2 nanosheet array for an efficient hydrogen evolution reaction.

The surface electronic structure and morphology of catalysts have a crucial impact on the electrocatalytic hydrogen evolution reaction performance. This work reports on the fabrication of a Ru-doped WP/WP2 heterojunction nanosheet array electrode via a one-step phosphating treatment of a Ru-doped WO3 precursor. Benefitting from the large electrochemical active surface of nanosheet arrays, rich WP/WP2 heterojunction interface, and trace Ru atom doping, the catalyst has a fairly low overpotential of 58.0 mV at 10 mA cm-2 and a Tafel slope of 50.71 mV dec-1 in acid solution toward the electrocatalytic HER. Further, theoretical calculations unveil that Ru atom doping and interface effect synergistically optimized the electronic structure of the catalyst and hence weakened the adsorption capacity of the catalyst surface toward hydrogen (H), which lowered the Gibbs free energy (ΔGH*) and consequently effectively improved the HER performance. This work may open new avenues for developing advanced nanoarray electrodes with efficient electrochemical energy conversion.

Optimizing the thermoelectric performance of n-type PbSe through dynamic doping driven by entropy engineering

This work utilized a collaborative optimization approach combining dynamic doping and entropy engineering to enhance the band degeneracy, enabling Pb0.875Sn0.125Se0.5Te0.25S0.25-2at%Cu to achieve excellent thermoelectric performance.

Synergistic optimization of the thermoelectric performance of BiSbSe3 using doping and multi-scale defect engineering

This work reveals the synergistic effect of codoping and multi-scale defect engineering on enhancing the thermoelectric properties of BiSbSe3 materials.

Enhancing CO2 electroreduction performance through transition metal atom doping and strain engineering in γ-GeSe: a first-principles study.

The development of electrocatalysts that exhibit stability, high activity, and selectivity for CO2 reduction reactions (CO2RR) remains a significant challenge. Single-atom catalysts (SACs) hold promise in addressing this challenge due to their high atomic utilization efficiency. In this study, we explore the potential of monolayer γ-GeSe doped with transition metals, referred to as TM@γ-GeSe, for facilitating electrocatalytic CO2RR. Among the 26 TM@γ-GeSe SACs systematically designed, we have identified four stable transition metal catalysts (TM = Rh, Pd, Pt, and Au). Mechanistic investigations into the CO2RR pathways reveal exceptional electrocatalytic activity for Rh@γ-GeSe and Pd@γ-GeSe, with limiting potentials of -0.26 and -0.35 V, respectively. Particularly, Pd@γ-GeSe exhibits outstanding product selectivity toward formic acid. The introduction of strain engineering induces modifications in the catalytic activity and selectivity of Rh@γ-GeSe. Notably, a 1% tensile strain promotes formic acid as the preferred product, thereby improving the specific product selectivity of Rh@γ-GeSe. Conversely, compressive strain reduces CO2RR activity while enhancing the hydrogen evolution reaction, leading to a decrease in CO2RR selectivity. Furthermore, we use the work function as a descriptor to elucidate the underlying mechanism of strain tunability. We hope that our theoretical study will offer valuable insights for the design of catalysts based on γ-GeSe for electrocatalytic CO2RR.

Ce-doping induces rapid electron transfer in a bimetallic phosphide heterostructure to achieve efficient hydrogen production.

Using electrochemical water splitting to generate hydrogen is considered a desirable approach, which is greatly impeded by the sluggish dissociation of H2O and adsorption and desorption of H*. Effective hydrogen production can be achieved by speeding up the chemical process with a suitable electrocatalyst. In this work, we designed and synthesized a rare earth element cerium (Ce) regulated iron-nickel bimetallic phosphide Ce-NiFeP@NF (here NiFeP represents Fe2P/NiP2) nanoarray with nanoflowers. For the hydrogen evolution reaction (HER), Ce-NiFeP@NF only needs an overpotential of 106 mV to provide a current density of 10 mA cm-2, compared to NiFeP@NF (175 mV@10 mA cm-2). This self-supported electrocatalyst Ce-NiFeP@NF with a composite morphology exhibits excellent performance in the HER. Specifically, the introduction of Ce promotes the electron transfer process at the Fe2P/NiP2 heterojunction interface and the Ce-NiFeP@NF nanocomposite structure with nanoflowers has a larger electrochemically active specific surface area, which is more conducive to improving the intrinsic catalytic activity. Also, a dual-electrode alkaline electrolytic cell (Ce-NiFeP@NF functions as both the anode and the cathode) operates with a cell voltage of only 1.56 V to achieve a current density of 10 mA cm-2. The synergistic effect of rare earth element doping and heterojunction engineering can improve the morphology of intrinsic catalysts to achieve more efficient electrochemical water splitting for hydrogen production.

Near-infrared two-photon excited photoluminescence from Yb3+-doped CsPbClxBr3-x perovskite nanocrystals embedded into amphiphilic silica microspheres.

Nonlinear absorption of metal-halide perovskite nanocrystals (NCs) makes them an ideal candidate for applications which require multiphoton-excited photoluminescence. By doping perovskite NCs with lanthanides, their emission can be extended into the near-infrared (NIR) spectral region. We demonstrate how the combination of Yb3+ doping and bandgap engineering of cesium lead halide perovskite NCs performed by anion exchange (from Cl- to Br-) leads to efficient and tunable emitters that operate under two-photon excitation in the NIR spectral region. By optimizing the anion composition, Yb3+-doped CsPbClxBr3-x NCs exhibited high values of two-photon absorption cross-section reaching 2.3 × 105 GM, and displayed dual-band emission located both in the visible (407-493 nm) and NIR (985 nm). With a view of practical applications of bio-visualisation in the NIR spectral range, these NCs were embedded into silica microspheres which were further wrapped with amphiphilic polymer shells to ensure their water-compatibility. The resulting microspheres with embedded NCs could be easily dispersed in both toluene and water, while still exhibiting a dual-band emission in visible and NIR under both one- and two-photon excitation conditions.

Towards metal selenides: a promising anode for sodium-ion batteries.

Metal selenides have garnered significant attention as promising anode materials for sodium-ion batteries, thanks to their high theoretical capacity, excellent conductivity, and natural abundance. However, their potential is hampered by disappointing capacity retention and unsatisfactory lifespan, primarily attributed to volume expansion and unwanted structural collapse resulting from the insertion and extraction of relatively large Na+ ions during the charge and discharge processes. This feature article provides a brief overview of our endeavors to address the challenges associated with metal selenide-based anode materials, aiming to achieve high-performance electrode materials for sodium-ion batteries. Our strategy encompasses nanostructure design, materials composite engineering, heteroatoms doping, and topography and interface engineering. Additionally, future research directions are also outlined.

Halogen doping of p-type inorganic hole transport layer: electronic nature-based dopant engineering for modulating hole selectivity in inverted planar perovskite solar cells

The role of metal cation and halide anion dopants in regulating the properties of NiOx hole transport layer (HTL) was explored. This study confirms that halide dopants also increase the Ni3+ defect density and work function of p-type inorganic HTL.

Great Wall structure inspired 2D@2D hetero-layered W-doped MoS2 towards enhanced hydrogen evolution reaction

Doping engineering of 2D layered molybdenum disulfide (MoS2) demonstrates attractive catalytic activity for hydrogen evolution reaction (HER), yet it remains challenged by unclear mechanisms. Herein, inspired by the Great Wall...

2D petal-like PdAg nanosheets promote efficient electrocatalytic oxidation of ethanol and methanol.

The development of efficient alcohol electrooxidation catalysts is of vital importance for the commercialization of direct liquid fuel cells. As emerging advanced catalysts, two-dimensional (2D) noble metal nanomaterials have attracted much research attention due to their intrinsic structural advantages. Herein, we report the synthesis of petal-like PdAg nanosheets (NSs) with an ultrathin 2D structure and jagged edges via a facile wet-chemical approach, combining doping engineering and morphology tuning. Notably, the highly active sites and Pd-Ag composition endowed PdAg NSs with improved toxicity tolerance and substantially improved the durability toward the ethanol/methanol oxidation reaction (EOR/MOR). Moreover, the electronic effect and synergistic effect significantly enhanced the EOR and MOR activities in comparison with Pd NSs and commercial Pd/C. This work provides efficient catalysts for fuel electrooxidations and deep insight into the rational design and fabrication of novel 2D nanoarchitecture.

Nitrogen doped 1 T/2H mixed phase MoS2/CuS heterostructure nanosheets for enhanced peroxidase activity

Heteroatom doping and phase engineering are effective ways to promote the catalytic activity of nanoenzymes. Nitrogen-doped 1 T/2H mixed phase MoS2/CuS heterostructure nanosheets N-1 T/2H-MoS2/CuS are prepared by a simple hydrothermal approach using polyoxometalate (POM)-based metal–organic frameworks (MOFs) (NENU-5) as a precursor and urea as nitrogen doping reagent. The XPS spectroscopy (XPS) and Raman spectrum of N-1 T/2H-MoS2/CuS prove the successful N-doping. NENU-5 was used as the template to prepare 1 T/2H-MoS2/CuS with high content of 1 T phase by optimizing the reaction time. The use of urea as nitrogen dopant added to 1 T/2H-MoS2/CuS, resulted in N-1 T/2H-MoS2/CuS with an increase in the content of the 1 T phase from 80 % to 84 % and higher number of defects. N-1 T/2H-MoS2/CuS shows higher peroxidase activity than 1 T/2H-MoS2/CuS and a catalytic efficiency (Kcat/Km) for H2O2 twice as high as that of 1 T/2H-MoS2/CuS. The enhanced catalytic activity has probably been attributed to several reasons: (i) the insertion of urea during the hydrothermal process in the S-Mo-S layer of MoS2, causing an increase in the interlayer spacing and in 1 T phase content, (ii) the replacement of S atoms in MoS2 by N atoms from the urea decomposition, resulting in more defects and more active sites. As far as we know, N-1 T/2H-MoS2/CuS nanosheets have the lowest detection limit (0.16 µm) for the colorimetric detection of hydroquinone among molybdenum disulfide-based catalysts. This study affords a new approach for the fabrication of high-performance nanoenzyme catalysts.

Enriched Se vacancies engineering of RuSe2 induced by low-valence Cu doping for promoting hydrogen evolution and coupling power generation

Heteroatom doping and vacancy engineering play vital roles in designing a high-activity electrocatalyst. Herein, we proposed a novel enriched Se vacancies engineering of the promising ruthenium chalcogenide of RuSe2 induced by low-valence Cu doping for promoting hydrogen evolution reaction (HER) electrocatalysis in alkaline media. The Cu-doped RuSe2 with enriched Se vacancies supported on graphitized carbon (Cu-RuSe2@C) was synthesized by a simple one-step selenization of bimetallic MOF precursor of Ru/Cu-BTC (1,3,5-benzenetricarboxylic acid) polyhedra. Compared to the Cu(Ⅱ)-dominant doped RuSe2 (CuⅡ/Ⅰ-RuSe2@C) with deficient Se vacancies, the proposed Cu(Ⅰ)-dominant doped RuSe2 (CuⅠ/Ⅱ-RuSe2@C) with enriched Se vacancies exhibited significantly improved electrocatalytic activity, which was potentially derived from the created electron-deficient Ruδ+ and Seν− sites induced by low-valence Cu doping. Specifically, CuⅠ/Ⅱ-RuSe2@C needed only 40 mV overpotential to drive a HER current density of 10 mA cm−2, comparable to commercial Pt/C (38 mV) and much lower than those of CuⅡ/Ⅰ-RuSe2@C (93 mV) and RuSe2@C (362 mV). Furthermore, an alkaline Zn-H2O fuel cell with a CuⅠ/Ⅱ-RuSe2@C cathode was integrated to demonstrate its potential applications, which delivered a maximum power density of 15.1 mW cm−2 and specific capacitance of 660 mAh g−1 with good stability. Two series-connected alkaline Zn-H2O cells acted as a chemical energy converter for simultaneous electricity generation and hydrogen coproduction by driving the coupled water splitting.

One-step Mo-doped praseodymium oxide construction of oxygen vacancies for efficient photothermal co-catalytic Suzuki coupling reaction

The photothermal synergistic catalytic Suzuki coupling reaction is a sustainable approach to generate biphenyl compounds using clean and renewable solar energy. The one-step Mo doping engineering resulted in more oxygen vacancies and surface free electrons on the PrxOy surface of hollow porous nanotube morphology. Subsequently, energy-efficient and environmentally friendly catalysts (PdO/PrxOy−Moz) with higher catalytic activity were successfully prepared by deposition precipitation method. The concave and convex surfaces of the carriers could better capture visible light. Mo doping greatly extends the visible absorption range of PrxOy. More OVs defects in the PrxOy−Moz carrier inhibit the complexation of photogenerated electron-hole pairs and induce the transfer of free and photogenerated electrons to Pd. The electron-rich Pd accelerated the oxidative addition step of aryl halides to aryl phenylboronic acids, which greatly improved the catalytic performance of PdO/PrxOy−Moz in the photothermal co-catalytic Suzuki coupling reaction.

Control of the magnetic anisotropy and Curie temperature of monolayer 1T-CrTe2 for room temperature application

Magnetic units with large magnetic anisotropy energy (MAE) and high Curie temperature (Tc) are crucial for spintronic and quantum computing devices, which are a persisting demand for miniaturization of magnetic units. Using first-principles calculations and Monte Carlo simulation, it is found that monolayer 1T-CrTe2 exhibits strong perpendicular magnetic anisotropy with a MAE of approximately 5.29 meV and high Tc of ∼136 K. Interestingly, we find that the MAE and Tc of monolayer 1T-CrTe2 are tunable through electron/hole doping, strain, and heterostructure engineering. The magnetic easy-axis can be adjusted from out of plane to in plane, which is mainly attributed to the coupling between Te atomic orbitals (px, py). Second-order perturbation theory reveals that the spin–orbit coupling interaction between the occupied px and unoccupied py orbitals in opposite spin channel near Fermi level gives rise to negative contribution of MAE. Moreover, Tc can be enhanced to ∼230 K through super–superexchange mechanism of heterostructure due to the electron hopping between t2g/eg orbitals of Cr4+ ions and e1/a1 orbitals of Fe2+ ions. Importantly, we find that Tc can be boosted above room temperature by applying moderate strain (6%), ascribing to significant enhancement of MAE and exchange coupling constant. The present work indicates that monolayer 1T-CrTe2-based two-dimensional materials are very promising for room temperature application in magnetic storage and information processing.

Atomic ruthenium doping in collaboration with oxygen vacancy engineering boosts the hydrogen evolution reaction by optimizing H absorption

Development of cost effective and performance efficient catalyst for hydrogen evolution reaction (HER) holds great importance to advance a green future. In this work, atomic Ru doped NiMoO4 nanorod arrays with rich oxygen vacancy were tailor-synthesized on nickel foam. Both theoretical calculations and experiments elucidated the synergistic effects of Ru doping and oxygen vacancy engineering for the facilitating of H adsorption and water activation energy barrier reduction for water dissociation, which significantly enhanced the hydrogen evolution kinetics and thereby accelerated the water splitting process. The sample obtained exhibits a remarkably low overpotential of 49 mV at 10 mA cm−2 and a super robust stability, which is comparable to the performance of commercially available Pt/C and among one of the most efficient catalysts towards water splitting. Moreover, an integrated green energy-to-hydrogen device using sunlight, wind and thermal as the power sources was successfully built to prove the promising potential of the developed catalyst for the practical applications. This work provides a feasible strategy to prepare low-cost metal oxide electrocatalysts by noble element doping and oxygen vacancy engineering for efficient hydrogen evolution reaction.

Visible to NIR-II Photoluminescence of Atomically Precise Gold Nanoclusters.

Atomically precise gold nanoclusters (NCs) have emerged as a new class of precision materials and attracted wide interest in recent years. One of the unique properties of such nanoclusters pertains to their photoluminescence (PL), for it can widely span visible to near-infrared-I and -II wavelengths (NIR-I/II), and even beyond 1700 nm by manipulating the size, structure, and composition. The current research efforts focus on the structure-PL correlation and the development of strategies for raising the PL quantum yields, which is nontrivial when moving from the visible to the near-infrared wavelengths, especially in the NIR-II regions. This review summarizes the recent progress in the field, including i) the types of PL observed in gold NCs such as fluorescence, phosphorescence, and thermally activated delayed fluorescence, as well as dual emission; ii) some effective strategies that are devised to improve the PL quantum yield (QY) of gold NCs, such as heterometal doping, surface rigidification, and core phonon engineering, with double-digit QYs for the NIR PL on the horizons; and iii) the applications of luminescent gold NCs in bioimaging, photosensitization, and optoelectronics. Finally, the remaining challenges and opportunities for future research are highlighted.

Metal-injection and interface density engineering induced nickel diselenide with rapid kinetics for high-energy sodium storage

The key to the innovation of sodium-ion batteries (SIBs) is to find efficient sodium-storage electrode. Here, metal Mo doping of NiSe2 is proposed by modified electrospinning strategy followed by in situ conversion process. The Mo-NiSe2 anchoring on hollow carbon nanofibers (HCNFs) would make full use of the multi-channel HCNFs in the inner layer and the active sites of Mo-NiSe2 in the outer layer, which plays an important role in buffering the volume stress of Na+ (de)insertion and reducing the adsorption energy barrier of Na+. Innovatively, it is proposed to jointly regulate the SIBs performance of NiSe2 by both metal atom doping and interface effects, thereby adjusting the sodium ion adsorption barrier of NiSe2. The Mo-NiSe2@HCNFs exhibits remarkable performance in SIBs, demonstrating a high specific capacity of 396 mAh/g after 100 cycles at 1 A/g. Moreover, it maintains outstanding cycling stability, retaining 77.6 % of its capacity (211 mAh/g) even after 1000 cycles at 10 A/g. This comprehensive electrochemical performances are due to the structural stability and outstanding electronic conductance of the Mo-NiSe2@HCNFs, as evidenced by the diffusion analysis and ex situ charge–discharge process characterization. Furthermore, coupled with the Na3V2(PO4)2O2F cathodes, the full cell also achieves a high energy density of 123 Wh kg−1. The theoretical calculation of the hypervalent Mo doing further proves the benefit of its Na+ adsorption and denser conduction band distribution. This study provides a reference for the construction of transition metal selenide via doping and interface engineering in sodium storage.

Unveiling The Role of Cu+ Doping in Rb2AgBr3 Scintillators toward Enhanced Photoluminescence Quantum Efficiency and Light Yield

AbstractDoping in luminescent metal halides has become an effective strategy for tailoring the optoelectronic properties. Herein, Cu+ is introduced into Rb2AgBr3 to design the synthesis of Rb2AgBr3:xCu+, which possess cold‐white light emission at room‐temperature without changing the spectral profiles; however, the Cu+ incorporation significantly enhances the photoluminescence quantum efficiency to 98.8% in Rb2AgBr3:0.05Cu+. Additionally, a high scintillation light yield of up to 79 250 photons MeV−1 and a low detection limit of 714.83 nGy s−1 have been achieved via this Cu+ doping engineering. X‐ray imaging with a spatial resolution of up to 5.8 lp mm−1 is further realized using a large scintillator film prepared by mixing polydimethylsiloxane with Cu+ doped Rb2AgBr3 scintillators. This study provides a Cu+ doping design principle for improving both the photoluminescence and scintillation performances of metal halides.

Manipulating Electron Redistribution in Ni2 P for Enhanced Alkaline Seawater Electrolysis.

Developing bifunctional electrocatalyst for seawater splitting remains a persistent challenge. Herein, an approach is proposed through density functional theory (DFT) preanalysis to manipulate electron redistribution in Ni2 P addressed by cation doping and vacancy engineering. The needle-like Fe-doped Ni2 P with P vacancy (Fe-Ni2 Pv) is successfully synthesized on nickel foam, exhibiting a superior bifunctional hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) catalytic activity for seawater electrolysis in alkaline condition. As a result, bifunctional Fe-Ni2 Pv achieves the industrially required current densities of 1.0 and 3.0 A cm-2 at low voltages of 1.68 and 1.73V, respectively, for seawater splitting at 60 °C in 6.0m KOH circumstances. The theoretical calculation and the experimental results collectively reveal the reasons for the enhancement of catalyst activity. Specifically, Fe doping and P vacancies can accelerate the reconstruction of OER active species and optimize the hydrogen adsorption free energy (ΔGH* ) for HER. In addition, the active sites of Fe-Ni2 Pv are identified, where P vacancies greatly improve the electrical conductivity and Ni sites are the dominant OER active centers, meanwhile Fe atoms as active centers for the HER. The study provides a deep insight into the exploration for the enhancement of activity of nickel-based phosphide catalysts and the identification of their real active centers.

Regulating d-orbital electronic configuration of Ni-based chalcogenides to enhance the oxygen electrode reactions in Li-O2 batteries

Transition metal chalcogenides based electrocatalysts with regulable d-orbital electronic configuration by various chalcogen anions can exhibit excellent oxygen electrode reaction kinetics in Li-O2 batteries (LOBs). In this work, an electron rearrangement strategy to improve the catalytic activity of hexagonal NiS microsheets for LOBs has been developed via introducing Se anion as a substitution of S. With the as-prepared NiS0.67Se0.33 as cathode catalyst, LOB could achieve evidently lower overpotentials, larger discharge capacity, and ultralong cycling life than that using NiS. With the help of physicochemical techniques and theoretical calculations, the performance enhancement of NiS0.67Se0.33 could be elucidated with its suitable d-orbital electronic configuration. Specifically, Se anion substitution can modulate metal–chalcogen interactions with increased charge density and positively shifted d-band center of Ni metal cation, thereby promoting the d-p orbitals hybridization with increased binding strength to LiO2 intermediates and promoting oxygen reduction/evolution reaction kinetics. Moreover, small amount of Ni dissolution from NiS0.67Se0.33 to the electrolyte because of the rearranged electronic configuration also contributes to the enhanced oxygen electrochemistry and improved LOB performance by serving as a redox mediate catalyst. This work provides a facile anion doping engineering to facilitate the oxygen electrode reactions in LOBs by modulating d-orbital electronic configuration.