Tunable Electronic Structure Research Articles

Tuning of the Bimetallic CoNi Electronic Structure for Inducing Catalytic Activity and Selectivity for Styrene Hydrogenation

Tuning of the Bimetallic CoNi Electronic Structure for Inducing Catalytic Activity and Selectivity for Styrene Hydrogenation

Chemically functionalized diamanes - A new class of hybrid 2D materials: DFT insight into crystal, mechanical, and electronic properties

This work describes crystal and electronic structures of a new class of 2D hybrid organic-inorganic compounds based on AB-stacked diamane. Seven members thereof are considered: methyl-, pyrrolyl-, 1,2,4-triazolyl-, phenyl-, pyridinyl-, and pyrimidinyl-substituted (two isomers) diamane. DFT calculations show that an electronic structure of diamane can be modulated by organic functional groups. The chemically functionalized diamanes are semiconductors with HSE06 electronic bandgaps falling in the range [2.09–4.91] eV. Other means of diamane electronic structure tuning include variation of coverage of a diamane surface by substituents, mixing of substituents and changing their mutual orientation. Based on the obtained results we conclude that the functionalized diamanes may serve as photovoltaic materials operable in Vis and near UV spectral regions. Owing to a similarity of the aromatics-substituted diamanes to low-dimensional hybrid metal halide perovskites with aromatic organic cations the former could be photoluminescent. An enhanced resistance of the investigated materials to water is expected.

Coordination Compound Derived Co9S8 Supported on Nitrogen and Sulfur Co‐Doped Porous Carbon for Oxygen Reduction Reaction

AbstractCobalt sulfide, a class of metal chalcogenide with tunable electronic structure and component distribution, has attracted considerable interest in renewable energy conversion and utilization. In this work, we report a facile, efficient and scalable method to synthesize Co9S8 supported on nitrogen and sulfur co doped porous carbon (Co9S8/N,S‐PC) hybrid from the annealing treatment of a coordination compound assembled by 2‐mercaptobenzimidazole, 4,4‐bipyridine and cobalt salt. The heteroatom of organic ligand could efficiently tune the electronic properties of Co9S8 nanoparticles and well‐designed carbon. Meanwhile the interaction of organic ligands provides a platform for the high dispersion of Co9S8. Owing to the synergetic effect, the Co9S8/N,S‐PC catalyst shows an admirable oxygen reduction reaction (ORR) activity with the E1/2 of 0.804 V vs. RHE, together with good durability, and tolerance to methanol poisoning in alkaline media.

Merocyanines: Electronic Structure and Spectroscopy in Solutions, Solid State, and Gas Phase.

Merocyanines, owing to their readily tunable electronic structure, are arguably the most versatile functional dyes, with ample opportunities for tailored design via variations of both the donor/acceptor (D/A) end groups and π-conjugated polymethine chain. A plethora of spectral properties, such as strong solvatochromism, high polarizability and hyperpolarizabilities, and sensitizing capacity, motivates extensive studies for their applications in light-converting materials for optoelectronics, nonlinear optics, optical storage, fluorescent probes, etc. Evidently, an understanding of the intrinsic structure-property relationships is a prerequisite for the successful design of functional dyes. For merocyanines, these regularities have been explored for over 70 years, but only in the past three decades have these studies expanded beyond the theory of their color and solvatochromism toward their electronic structure in the ground and excited states. This Review outlines the fundamental principles, essential for comprehension of the variable nature of merocyanines, with the main emphasis on understanding the impact of internal (chemical structure) and external (intermolecular interactions) factors on the electronic symmetry of the D-π-A chromophore. The research on the structure and properties of merocyanines in different media is reviewed in the context of interplay of the three virtual states: nonpolar polyene, ideal polymethine, and zwitterionic polyene.

Turning Microenvironments of Porous Co─N─C Catalysts Enable Efficient Fenton-Like Reaction.

Metal nitrogen carbon (MNC)-based Fenton reactions leveraged with robust peroxymonosulfate (PMS) interaction effectively guarantee the elimination of refractory contaminants, yet the precise design of local microenvironment of MNC to couple with the multiple PMS activation pose major challenges. Herein, a porous Co single-atom catalyst (SAC) with nitrogen defects (Nv) (MCo/NC-6) is fabricated to initiate PMS oxidation reaction. The weaker but richer coordination between Co and N in the precursor facilitates the formation of Nv and porous structure during pyrolysis, achieving simultaneously electronic structure and spatial distribution tuning. Compared with the Co SAC (ZCo/NC-6), the optimized MCo/NC-6 significantly increase the bisphenol A (BPA) reactivity (k = 0.63 min-1), PMS utilization (78%), and singlet oxygen (1O2) yield (100%) by 15.3, 2.4, and 2.6 times, respectively. Experimental analyses and theoretical calculations reveal that the Co─N─C coordination regulated by both micro space and neighboring Nv is endowed high-mobility electrons, thus synergistically facilitating rapid generation and efficient utilization of 1O2. This work promises new opportunities for the design of local microenvironments-regulated SACs, and charts new trajectories in complex Fenton-like systems.

Advancements and Applications of Single-Atom Nanozymes in Sensing Analysis

Single-atom nanozymes, with their atomically dispersed metal active sites, distinctive atom utilization rate, and tunable electronic structure, demonstrate great promise in the field of sensing analysis. This paper reviews the latest research progress on single-atom nanozymes in sensing applications. We classify single-atom nanozymes based on both their structural characteristics, such as carbon-based carriers, frameworks and their derivatives, metal oxides, metal sulfides, and organic polymer carriers, and their unique catalytic properties, including peroxidase, oxidase, catalase, superoxide dismutase, and multi-enzyme mimetic activities. Furthermore, we discuss the application of single-atom nanozymes in the sensitive detection of biological small molecules, antioxidants, ions, enzyme activities and their inhibitors, as well as cells and viruses. Finally, we highlight the opportunities and challenges for advancing the practical application and further research of single-atom nanozymes in the field of sensing analysis.

Boosting exciton dissociation in conjugated microporous polymers via molecular isomerization for photocatalytic degradation of antibiotics

Photocatalytic degradation of antibiotics from wastewater by polymeric photocatalysts is a powerful strategy to alleviate ecological damage and environmental pollution. Conjugated microporous polymers (CMPs) are promising in photocatalysis due to their tunable electronic structure and excellent light absorption. Nonetheless, CMPs still suffer from low exciton separation efficiency. Here, we propose a molecular isomerism strategy to promote exciton dissociation in CMPs by modulating the position of the carbonyl moiety. As a result, the introduction of carbonyl moiety with different substitution positions into the backbone of CMPs could minimize the exciton binding energy (Eb) and thus promote charge separation. PyCMPs-3 with phenanthrenequinone moiety as the acceptor featured a lower Eb of 37.19 meV, which are much smaller than that of carbonyl-free PyCMPs-1 (80.49 meV) and PyCMPs-2 (59.21 meV) with anthraquinone as the acceptor. Among them, PyCMPs-3 performed the best in photocatalytic degradation of ofloxacin (99 %) at a concentration of 144 ppm, which was significantly higher than that of its analogues PyCMPs-1 (26 %) and PyCMPs-2 (57 %) within 100 min under visible light exposure. In short, this work delivered a novel molecular isomerism strategy to minimize Eb by regulating the position of the carbonyl moiety for enhancing the photocatalytic degradation efficiency, promoting the development of CMPs for practical environmental remediation applications.

Advancements in Rechargeable Zn-Air Batteries with Transition-Metal Dichalcogenides as Bifunctional Electrocatalyst.

This review covers recent progress on transition metal dichalcogenides (TMDs) as bifunctional electrocatalysts for Zinc-air batteries (ZABs), emphasizing their suitable surface area, electrocatalytic active sites, stability in acidic/basic environments, and tunable electronic properties. It discusses strategies like defect engineering, doping, interface, and structural modifications of TMDs nanostructures for enhancing the performances of ZABs. Zinc-air batteries are promising energy storage devices owing to their high energy density, low cost, and environmental friendliness. However, the development of durable and efficient bifunctional electrocatalysts is a major concern for Zn-air batteries. In this review, we summarize the recent progress on transition metal dichalcogenides (TMDs) as bifunctional electrocatalysts for Zn-air batteries. We discuss the advantages of TMDs, such as high activity, good stability, and tunable electronic structure, as well as the challenges, such as low conductivity, poor durability, and limited active sites. We also highlight the strategies for fine-tuning the properties of TMDs, such as defect engineering, doping, hybridization, and structural engineering, to enhance their catalytic performance and stability. We provide a comprehensive and in-depth analysis of the applications of TMDs in Zn-air batteries, demonstrating their potential as low-cost, abundant, and environmentally friendly alternatives to noble metal catalysts. We also suggest future directions like exploring new TMDs materials and compositions, developing novel synthesis and modification techniques, investigating the interfacial interactions and charge transfer processes, and integrating TMDs with other functional materials. This review aims to illuminate the path forward for the development of efficient and durable Zn-air batteries, aligning with the broader objectives of sustainable energy solutions.

Graphene‐Transition Metal Electrocatalysts for Sustainable Water Electrolysis

AbstractTransition metal compounds (TMCs) are potentially fruitful substitutes for noble metals for electrocatalytic splitting of water due to their intrinsic electrocatalytic activity, modifiable morphology, tunable electronic structure and their earth‐abundance. The combination of TMCs with graphene improves the dispersion of loaded catalysts, providing more catalytic active sites, enhancing the conductivity of hybrids, affording accelerated charge‐transfer kinetics, and minimizing catalyst bleaching, aggregation, and sintering under harsh reaction conditions. Additionally, graphene incorporation into TMCs modulates the electronic structure of active centers because of the synergistic interaction between them, thereby improving their catalytic performance. This review paper focuses on the recent progress made in designing different graphene‐transition metal‐based materials that can be used in the hydrogen evolution reaction (HER), the oxygen evolution reaction (OER), and overall water splitting (OWS). In‐situ characterization methodologies and DFT calculations that facilitate catalyst development are discussed elaborately. Finally, the advancements made in the development of graphene‐supported transition metal compounds for use in a functional water electrolyzer have been explored. In conclusion, a few specific recommendations have been made about the current challenges related to the widespread production of effective HER/OER electrocatalysts for water electrolysis.

Rational Design of ZnO/Sc2CF2 Heterostructure with Tunable Electronic Structure for Water Splitting: A First-Principles Study

Heterostructures are highly promising photocatalyst candidates for water splitting due to their advanced properties than those of pristine components. The ZnO/Sc2CF2 heterostructure was designed in this work, and its electronic structure was investigated to explore its potential for water splitting. The assessments of binding energy, phonon spectrum, ab initio molecular dynamics, and elastic constants provide strong evidence for its stability. The ZnO/Sc2CF2 heterostructure has an indirect band gap of 1.93 eV with a type-Ⅰ band alignment. The electronic structure can be modified with strain, leading to a transition in band alignment from type-Ⅰ to type-Ⅱ. The heterostructure is suitable for water splitting since its VBM and CBM stride over the redox potential. The energy barrier and built-in electric field, resulting from the charge transfer, facilitate the spatial separation of photogenerated carriers, enhancing their utilization efficiency for redox processes. The photogenerated carriers in the heterostructures with lattice compression greater than 6% follow the direct-Z transfer mechanism. The ZnO/Sc2CF2 heterostructure is confirmed with high photocatalytic activity by a Gibbs free energy change of HER, which is 0.89 eV and decreases to −0.52 eV under an 8% compressive strain. The heterostructure exhibits a remarkable enhancement in both absorption range and intensity, which can be further improved with strains. All these findings suggest that the ZnO/Sc2CF2 heterostructure is an appreciated catalyst for efficient photocatalytic water splitting.

Atomic-scale strain engineering of atomically resolved Pt clusters transcending natural enzymes

Strain engineering plays an important role in tuning electronic structure and improving catalytic capability of biocatalyst, but it is still challenging to modify the atomic-scale strain for specific enzyme-like reactions. Here, we systematically design Pt single atom (Pt1), several Pt atoms (Ptn) and atomically-resolved Pt clusters (Ptc) on PdAu biocatalysts to investigate the correlation between atomic strain and enzyme-like catalytic activity by experimental technology and in-depth Density Functional Theory calculations. It is found that Ptc on PdAu (Ptc-PA) with reasonable atomic strain upshifts the d-band center and exposes high potential surface, indicating the sufficient active sites to achieve superior biocatalytic performances. Besides, the Pd shell and Au core serve as storage layers providing abundant energetic charge carriers. The Ptc-PA exhibits a prominent peroxidase (POD)-like activity with the catalytic efficiency (Kcat/Km) of 1.50 × 109 mM−1 min−1, about four orders of magnitude higher than natural horseradish peroxidase (HRP), while catalase (CAT)-like and superoxide dismutase (SOD)-like activities of Ptc-PA are also comparable to those of natural enzymes. Biological experiments demonstrate that the detection limit of the Ptc-PA-based catalytic detection system exceeds that of visual inspection by 132-fold in clinical cancer diagnosis. Besides, Ptc-PA can reduce multi-organ acute inflammatory damage and mitigate oxidative stress disorder.

Construction of a novel Mott-Schottky heterostructure gas sensor g-C3N4/SnO2 with layered nanorods array for high-sensitivity acetone detection

Developing exhaled acetone sensors with high performance can be effectively applied to the medical diagnosis and the health monitoring. Herein, a two-dimensional (2D) layered graphitic carbon nitride (g-C3N4) with tunable electronic structure, abundant edge sites, and high stability is proposed, and it is further coupled with stannic oxide (SnO2) by one-step hydrothermal approach to construct a Mott-Schottky heterostructure with layered nanorods array. The exceptional response of the as-fabricated g-C3N4/SnO2 gas sensor to 50 ppm acetone at 100 °C is four times higher than that of the pristine SnO2 sensor. Additionally, the g-C3N4/SnO2 sensor’s remarkable selectivity, long-term stability against acetone gas, and detection limit of 250 ppb are exhibited. The unique hierarchical design and the Mott-Schottky heterostructure creation which validated by electrochemical study, may be in charge of the enhanced acetone sensing capabilities of g-C3N4/SnO2 gas sensor. This work will provide a concise and effective avenue to construct hierarchical composite with Mott-Schottky heterostructure for high-performance acetone gas sensor.

Arrayed metal phosphide heterostructure by Fe doping for robust overall water splitting

Transition metal phosphides (TMPs) show promise in water electrolysis due to their electronic structures, which activate hydrogen/oxygen reaction intermediates. However, TMPs face limitations in catalytic efficiency due to insufficient active sites, poor conductivity, and multiple intermediate steps in water electrolysis. Here, we synthesize a highly efficient bifunctional self-supported electrocatalyst, which consists of an N-doped carbon shell anchored on Fe-doped CoP/Co2P arrays on nickel foam (NC@Fe-CoxP/NF) using hydrothermal and phosphorization techniques. Experimental and theoretical results indicate that the modified morphology, with increased active site density and a tunable electronic structure induced by Fe doping in the CoP/Co2P heterostructure, leads to superior water electrolysis performance. The resulting NC@Fe0.1-CoP/Co2P/NF catalyst exhibits overpotentials of 122 mV for the hydrogen evolution reaction (HER) and 270 mV for the oxygen evolution reaction (OER) at 100 mA cm−2. Furthermore, using NC@Fe0.1-CoP/Co2P/NF as both the cathode and anode in an alkaline electrolyzer enables the cell system to achieve 100 mA cm−2 at a voltage of 1.70 V, while maintaining long-term catalytic durability. This work may pave the way for designing self-supported, highly efficient electrocatalysts for practical water electrolysis applications.

Unraveling Lewis acid-base sites in defected MOFs for catalyzing dicyclopentadiene hydrogenation via a DFT study and descriptor exploration

The 12-connected UiO-66 MOFs with great defect regulation ability have attracted significant attention due to the easily tunable electronic structure and surface electrostatic potential distribution of metal nodes. In this density functional theory (DFT) study, we systematically explored the effect of bi-active site types as the frustrated Lewis pair (FLP) and classical Lewis pair (LP) as well as metal elements of secondary building units (SBUs) on the catalytic hydrogenation of dicyclopentadiene (DCPD) to tetrahydrodicyclopentadiene (THDCPD). These design strategies effectively modulate the frontier molecular orbital energy level that determines the binding strength between MOFs and adsorbed species *Hδ+-Hδ- and charges transfer before and after H2 chemisorption. We also found that the heterolytic H2 adsorption energy and charges transfer linearly correlate with the energy barrier. In order to unravel the clear-cut designing strategies and further simplify computational complexity, we firstly proposed the ADCH charges difference between the Lewis acid and the Lewis base centers (ΔQM-O) as an intrinsic descriptor for catalytic activity of DCPD into THDCPD, which can effectively describe the reactivity and electrostatic effects of oppositely charged bi-active sites in the system. Furthermore, the defective UiO-66(Ce) MOF with moderate ΔQM-O effectively balance the contradiction between the barriers of two primitive reaction: the heterolytically H2 dissociation to *Hδ+-*Hδ- and the desorption of the active hydrogen species to hydrogenate 8,9-dihydrodicyclopentadiene (8,9-DHDCPD), resulting in the optimal catalytic performance. This work provides a deep understanding of the catalytic mechanism of MOFs with multiple active sites and might open up avenues for the rational design of novel hydrogenation catalysts.

Symbolic transform optimized convolutional neural network model for high-performance prediction and analysis of MXenes hydrogen evolution reaction catalysts

Two-dimensional MXenes materials are expected to be cost-effective and efficient catalysts for hydrogen evolution reaction (HER) due to their tunable surface electronic structure. To optimize its catalytic activity, this study proposes a data-driven framework (CROSST) to generate descriptors through feature engineering and integrate them into a convolutional neural network to predict the HER performance of transition-metal (TM) anchored bis-transition-metal carbon-nitride (TM-M′2M′′CNO2) catalysts. The STCNN model achieves a coefficient of determination of more than 0.93, showing the ability to predict the Gibbs free energy of hydrogen adsorption (ΔGH) with high accuracy. We explored the microscopic mechanisms of HER activity through density functional theory and machine learning analysis. It was found that TM anchoring altered the charge distribution of the MXenes material, elevated the atomic orbital occupancy of neighboring O sites, and weakened the O adsorption of H, thus affecting the HER activity. These results provide a theoretical basis for the design of high-performance MXenes HER catalysts and contribute new research perspectives.

Advancing Electrically Conductive Metal-Organic Frameworks for Photocatalytic Energy Conversion.

ConspectusPhotocatalytic energy conversion is a pivotal process for harnessing solar energy to produce chemicals and presents a sustainable alternative to fossil fuels. Key strategies to enhance photocatalytic efficiency include facilitating mass transport and reactant adsorption, improving light absorption, and promoting electron and hole separation to suppress electron-hole recombination. This Account delves into the potential advantages of electrically conductive metal-organic frameworks (EC-MOFs) in photocatalytic energy conversion and examines how manipulating electronic structures and controlling morphology and defects affect their unique properties, potentially impacting photocatalytic efficiency and selectivity. Moreover, with a proof-of-concept study of photocatalytic hydrogen peroxide production by manipulating the EC-MOF's electronic structure, we highlight the potential of the strategies outlined in this Account.EC-MOFs not only possess porosity and surface areas like conventional MOFs, but exhibit electronic conductivity through d-p conjugation between ligands and metal nodes, enabling effective charge transport. Their narrow band gaps also allow for visible light absorption, making them promising candidates for efficient photocatalysts. In EC-MOFs, the modular design of metal nodes and ligands allows fine-tuning of both the electronic structure and physical properties, including controlling the particle morphology, which is essential for optimizing band positions and improving charge transport to achieve efficient and selective photocatalytic energy conversion.Despite their potential as photocatalysts, modulating the electronic structure or controlling the morphology of EC-MOFs is nontrivial, as their fast growth kinetics make them prone to defect formation, impacting mass and charge transport. To fully leverage the photocatalytic potential of EC-MOFs, we discuss our group's efforts to manipulate their electronic structures and develop effective synthetic strategies for morphology control and defect healing. For tuning electronic structures, diversifying the combinations of metals and linkers available for EC-MOF synthesis has been explored. Next, we suggest that synthesizing ligand-based solid solutions will enable continuous tuning of the band positions, demonstrating the potential to distinguish between photocatalytic reactions with similar redox potentials. Lastly, we present incorporating a donor-acceptor system in an EC-MOF to spatially separate photogenerated carriers, which could suppress electron-hole recombination. As a synthetic strategy for morphology control, we demonstrated that electrosynthesis can modify particle morphology, enhancing electrochemical surface area, which will be beneficial for reactant adsorption. Finally, we suggest a defect healing strategy that will enhance charge transport by reducing charge traps on defects, potentially improving the photocatalytic efficiency.Our vision in this Account is to introduce EC-MOFs as an efficient platform for photocatalytic energy conversion. Although EC-MOFs are a new class of semiconductor materials and have not been extensively studied for photocatalytic energy conversion, their inherent light absorption and electron transport properties indicate significant photocatalytic potential. We envision that employing modular molecular design to control electronic structures and applying effective synthetic strategies to customize morphology and defect repair can promote charge separation, electron transfer to potential reactants, and mass transport to realize high selectivity and efficiency in EC-MOF-based photocatalysts. This effort not only lays the foundation for the rational design and synthesis of EC-MOFs, but has the potential to advance their use in photocatalytic energy conversion.

Mechanochemical synthesis of nitrogen-modified microscale zero-valent iron for efficient Cr(VI) removal: The role of lattice strain

Lattice engineering of Fe0 based on heteroatom doping holds great promise in water purification owing to their tunable geometric and electronic structure. However, there is limited understanding of how nitrogen atom in Fe0 lattice structure affects its local microenvironment and corresponding reactivity toward target contaminants. Herein, microscale zero-valent iron with interstitial N doping (N-mZVI) was successfully prepared by a facile mechanochemical method for heavy metal pollution control. N-mZVI exhibited excellent reactivity for Cr(VI) elimination, and both removal efficiency and conversion rate could reach 100 %, which was 8.06 and 2.73 times higher than that of pristine ball milled mZVI, respectively. Besides, the rate constant of various heavy metals sequestration (Cr(VI), Ni(II), Pb(II), Cu(II), and Cd(II)) over N-mZVI was 61.3 ∼ 115.6-fold faster than that of pristine ball milled mZVI. N-mZVI was also demonstrated to be pH-universal, long-term stability, and environmental applicability. Experimental results and theoretical calculations indicated that tensile strain induced by interstitial N doping expanded Fe0 lattice and weakened the lattice Fe-Fe interaction, thus significantly accelerating electron transport dynamics in Fe0 core. Meanwhile, iron nitride species on the surface of N-mZVI promoted electron transfer from iron shell layer to heavy metals. This work comprehensively investigates the structure–property relationships of lattice engineering-based N-mZVI, and provides a new insight into rational design of modified mZVI with high reactivity.

G-C3N4-Based Photocatalytic Materials for Converting CO2 Into Energy: A Review.

Environmental pollution management and renewable energy development are humanity's biggest issues in the 21st century. The rise in atmospheric CO2, which has surpassed 400 parts per million, has stimulated research on CO2 reduction and conversion methods. Presently, photocatalytic conversion of CO2 to valuable hydrocarbons enables the transformation of solar energy into chemical energy and offers a novel avenue for energy conversion while regulating the greenhouse effect. This is an ideal strategy for simultaneously addressing environmental issues and the energy crisis. Photocatalysts are essential to photocatalytic processes. Photocatalyst is the core of photocatalytic technology, and graphite carbon nitride (g-C3N4) has attracted much attention because of its nonmetallic characteristics, and it has the characteristics of low cost, tunable electronic structure, easy manufacture and strong reducibility. However, its activity is not only affected by external reaction conditions, but also by the band gap structure, physical and chemical stability, surface morphology and specific surface area of the photocatalyst it. In this paper, the application progress of g-C3N4-based photocatalytic materials in CO2 reduction is reviewed, and the modification strategies of g-C3N4-based catalysts to obtain better catalytic efficiency and selectivity in CO2 photocatalytic reduction are summarized, and the future development of this material is prospected.

Enriching the active sites of nanosheets assembled as flower-like MoS2 microstructure by controllable morphology for electrochemical hydrogen evolution reaction

With their tunable electronic structure, transition metal dichalcogenides offer a high surface area and enhanced active sites, making them a promising electrocatalyst for hydrogen production techniques. However, restacking of 2D layers and particle aggregation during material preparation negate its advantages. Herein, we developed a flower-like morphology with numerous molybdenum disulfide (1T/2H MoS2) nanosheet petals. The final formation and arrangements of MoS2 were validated through three distinct approaches: air (AD-M), vacuum (VD-M), and freeze-drying (FD-M). Interestingly, the drying phenomenon effectively alters the stacking and aggregation between the flower petals in the MoS2 and the electrocatalytic activity. Among the different drying processes, the FD-M exhibits minimal stacking and agglomeration between the nanoflowers. The FD-M exhibits remarkable catalytic activity in 1 M KOH for HER, reaching 10 mA cm−2 at a low overpotential (η10) of 198 mV and a small Tafel slope of 58.5 mV dec−1, which is lower than the AD-M (228 mV) and VD-M (215 mV). The FD process modulates the electronic structure of MoS2 by lowering stacking between layers, which effectively increases the ECSA and boosts the HER performance.

Mechanism study of trimetallic single-cluster catalysts loaded on graphdiyne for highly efficient oxygen-reduction reactions

Single-cluster catalysts (SCCs) have become a research hotspot due to their abundant active sites and tunable interatomic electronic structure, demonstrating excellent catalytic properties. However, the diversity of metal species in SCCs leads to unclear intrinsic activity toward metals and interaction between different metal species. In this manuscript, the impact of a series of precious metal-based (Ru, Rh, Pd, Ag, Os, Ir, Pt, and Au) trimetallic SCCs loaded on graphdiyne (UxVyWz@GDY) on the performance of the oxygen reduction reaction (ORR) is investigated using first-principles. The results show that the 18 holes of graphdiyne (GDY) efficiently achieve uniform doping of trimetallic clusters. In the UxVyWz@GDY structure, Pt3@GDY, Pt2Pd@GDY, and AuPdPt@GDY displayed high thermodynamic limit potentials near the top of the volcano plot at 0.79 eV, 0.80 eV, and 0.82 eV, respectively. These catalysts also show low overpotentials of 0.44 V, 0.43 V and 0.50 V, respectively. Deeper scrutiny of the interaction mechanism between *OH and the catalytic sites on Pt3@GDY, Pt2Pd@GDY, and AuPdPt@GDY unveils the pivotal role of electron transfer and intermetallic interactions in modulating the d-band center. Notably, the observed left shift of the d-band center in these catalysts, leading to the generation of more electron-deficient centers, effectively mitigates the issue of over-absorption between *OH and metal active sites, thereby significantly enhancing *OH desorption. This work provides inspiration for the efficient design of trimetallic SCCs.