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Engineering atom-scale sites are crucial to the mitigation of polysulfide shuttle, promotion of sulfur redox, and regulation of lithium deposition in lithium–sulfur batteries. Herein, a homonuclear copper dual-atom catalyst with a proximal distance of 3.5 Å is developed for lithium–sulfur batteries, wherein two adjacent copper atoms are linked by a pair of symmetrical chlorine bridge bonds. Benefiting from the proximal copper atoms and their unique coordination, the copper dual-atom catalyst with the increased active interface concentration synchronously guide the evolutions of sulfur and lithium species. Such a delicate design breaks through the activity limitation of mononuclear metal center and represents a catalyst concept for lithium–sulfur battery realm. Therefore, a remarkable areal capacity of 7.8 mA h cm−2 is achieved under the scenario of sulfur content of 60 wt.%, mass loading of 7.7 mg cm−2 and electrolyte dosage of 4.8 μL mg−1. Here, the authors report a homonuclear cooper dual-atom electrocatalyst with high activity designed for synchronously boosting the sulfur and lithium evolutions. [ABSTRACT FROM AUTHOR]

Designing high-performance electrocatalysts toward hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is essential to reduce the activation barrier and optimize free adsorption energy of reactive intermediates. Herein, we report that incorporating high-valence Cr into NiSe2 (CrxNi1−xSe2) kinetically and thermodynamically expedites elementary steps of both HER and OER. The as-prepared Cr0.05Ni0.95Se2 catalyst displays excellent HER and OER activities, with low overpotentials of 89 and 272 mV at the current density of 10 mA·cm−2 (j10), respectively, and remains stable during operation for 30 h. A low cell voltage of only 1.59 V is required to drive j10 in alkaline media. In situ Raman spectroscopy reveals that Cr incorporation facilitates the formation of NiOOH active species during the OER process. Meanwhile, theoretical explorations demonstrate that high-valence Cr incorporation efficiently accelerates water dissociation kinetics and improves H* adsorption during HER process, lowering the activation barrier of OER and optimizing the adsorption energy of oxygen-based intermediate, thus kinetically and thermodynamically enhancing the intrinsic performance of NiSe2 for over water splitting. This strategy provides a new horizon to design transition metal based electrocatalysts in the clean energy field. [ABSTRACT FROM AUTHOR]

Highlights: A unique atomic dispersed hetero-pair was successfully synthesized, consisting of Mo-Fe di-atoms anchored on N-doped carbon carrier. This strategy breaks the linear scaling relationships of electrocatalytic CO2 reduction by simultaneously regulating the *COOH adsorption energy and *CO desorption energy. The as-prepared MoFe–N–C exhibits excellent performance for CO2RR to CO with a high turnover frequency (TOF) of 3336.21 h−1, CO Faradaic efficiency (FECO) of 95.96% at − 0.60 V (versus RHE) and outstanding stability. Electrochemical carbon dioxide reduction reaction (CO2RR) involves a variety of intermediates with highly correlated reaction and ad-desorption energies, hindering optimization of the catalytic activity. For example, increasing the binding of the *COOH to the active site will generally increase the *CO desorption energy. Breaking this relationship may be expected to dramatically improve the intrinsic activity of CO2RR, but remains an unsolved challenge. Herein, we addressed this conundrum by constructing a unique atomic dispersed hetero-pair consisting of Mo-Fe di-atoms anchored on N-doped carbon carrier. This system shows an unprecedented CO2RR intrinsic activity with TOF of 3336 h−1, high selectivity toward CO production, Faradaic efficiency of 95.96% at − 0.60 V and excellent stability. Theoretical calculations show that the Mo-Fe diatomic sites increased the *COOH intermediate adsorption energy by bridging adsorption of *COOH intermediates. At the same time, d-d orbital coupling in the Mo-Fe di-atom results in electron delocalization and facilitates desorption of *CO intermediates. Thus, the undesirable correlation between these steps is broken. This work provides a promising approach, specifically the use of di-atoms, for breaking unfavorable relationships based on understanding of the catalytic mechanisms at the atomic scale. [ABSTRACT FROM AUTHOR]

Grain boundary engineering is a versatile tool for strengthening materials by tuning the composition and bonding structure at the interface of neighboring crystallites, and this method holds special significance for materials composed of small nanograins where the ultimate strength is dominated by grain boundary instead of dislocation motion. Here, we report a large strengthening of a nanocolumnar copper film that comprises columnar nanograins embedded in a bamboo-like boron framework synthesized by magnetron sputtering co-deposition, reaching the high nanoindentation hardness of 10.8 GPa among copper alloys. The boron framework surrounding copper nanograins stabilizes and strengthens the nanocolumnar copper film under indentation, benefiting from the high strength of the amorphous boron framework and the constrained deformation of copper nanocolumns confined by the boron grain boundary. These findings open a new avenue for strengthening metals via construction of dual-phase nanocomposites comprising metal nanograins embedded in a strong and confining light-element grain boundary framework. Achieving strength and toughness synergy via microstructure design is challenging in materials science. Here, the authors construct a bamboo-like dual-phase copper-boron structure that has unique mechanical response resulting in simultaneous increase in hardness, strength, and ductility. [ABSTRACT FROM AUTHOR]

Carbon monoxide electroreduction (COER) has been a key part of tandem electrolysis of carbon dioxide (CO2), in which searching for high catalytic performance COER electrocatalysts remains a great challenge. Herein, by means of density functional theory (DFT) computations, we explored the potential of a series of transition metal atoms anchored on N-doped γ-graphyne (TM@N-GY, TM from Ti to Au) as the COER electrocatalysts. We found that the final product selectivity of these single-atom catalysts depended on the position of the metal atom in the periodic table, with metals in the front and middle of each periodic period exhibiting high selectivity for CH4, while metals in the back producing CH3OH. Machine learning (ML) found that metal atomic number was intrinsic to the difference in COER performance of these single-atom catalysts (SACs). The free energy changes showed that Mn@N-GY and Ni@N-GY exhibited outstanding COER catalytic performance for producing CH4 and CH3OH, respectively. Our results provide theoretical and experimental guidance for designing efficient COER catalysts to generate C1 products. [ABSTRACT FROM AUTHOR]

Modulation of the surface electron distribution is a challenging problem that determines the adsorption ability of catalytic process. Here, we address this challenge by bridging the inner and outer layers of the core—shell structure through the bridge Br atom. Carbon shell wrapped copper bromide nanorods (CuBr@C) are constructed for the first time by chemical vapour deposition with hexabromobenzene (HBB). HBB pyrolysis provides both bridge Br atom and C shells. The C shell protects the stability of the internal halide structure, while the bridge Br atom triggers the rearrangement of the surface electrons and exhibits excellent electrocatalytic activity. Impressively, the hydrogen evolution reaction (HER) activity of CuBr@C is significantly better than that of commercial N-doped carbon nanotubes, surpassing commercial Pt/C at over 200 mA·cm−2. Density functional theory (DFT) calculations reveal that bridge Br atoms inspire aggregation of delocalized electrons on C-shell surfaces, leading to optimization of hydrogen adsorption energy. [ABSTRACT FROM AUTHOR]

It is challenging for precise governing of electronic configuration of the individually-atomic catalysts toward optimal electrocatalysis, as d-band configuration of a metal center determines the adsorption behavior of reactive species to the center in oxygen reduction reaction (ORR). The addition of Cu atom modifies the d-band center position of Fe central atom, thus strengthening the d—π* orbital interactions. Herein, FeCu-NC catalyst in the nitrogen-doped carbon (NC) support containing individual dual-metal CuN4/FeN4 sites was prepared by the surface confinement strategy of zeolitic imidazolate framework (ZIF), treated as a model catalyst. Experimentally and theoretically co-verified dual-metal CuN4/FeN4 sites highly dispersed in the NC support, enable transferring more electrons from FeN4 sites to *OH intermediates, thereby accelerating the desorption process of *OH species. Superior to those commercial Pt/C, Our FeCu-NC catalyst exhibited extraordinary ORR activity (with a E1/2 as high as 0.87 V) and cycling stability in 0.1 M KOH electrolyte, and thereof demonstrated excellent discharge performance in zinc-air batteries. Our construction of dual-atom catalysts (DACs) provides a strategy for atom-by-atom designing high-efficiency catalysts via orbital regulation. [ABSTRACT FROM AUTHOR]

Highlights: All the synthesis routes and surfaced-modified strategy of MXene-derived quantum dots (MQDs), the synthesis of MQDs-based nanocomposites, and advanced characterization techniques of MQDs are fully covered. Catalytic application is classified and discussed by judging the roles of MQDs. Current challenge and prospect are proposed for promoting the development and catalytic application of MQDs.It is well known that two-dimensional (2D) MXene-derived quantum dots (MQDs) inherit the excellent physicochemical properties of the parental MXenes, as a Chinese proverb says, “Indigo blue is extracted from the indigo plant, but is bluer than the plant it comes from.” Therefore, 0D QDs harvest larger surface-to-volume ratio, outstanding optical properties, and vigorous quantum confinement effect. Currently, MQDs trigger enormous research enthusiasm as an emerging star of functional materials applied to physics, chemistry, biology, energy conversion, and storage. Since the surface properties of small-sized MQDs include the type of surface functional groups, the functionalized surface directly determines their performance. As the Nobel Laureate Wolfgang Pauli says, “God made the bulk, but the surface was invented by the devil,” and it is just on the basis of the abundant surface functional groups, there is lots of space to be thereof excavated from MQDs. We are witnessing such excellence and even more promising to be expected. Nowadays, MQDs have been widely applied to catalysis, whereas the related reviews are rarely reported. Herein, we provide a state-of-the-art overview of MQDs in catalysis over the past five years, ranging from the origin and development of MQDs, synthetic routes of MQDs, and functionalized MQDs to advanced characterization techniques. To explore the diversity of catalytic application and perspectives of MQDs, our review will stimulate more efforts toward the synthesis of optimal MQDs and thereof designing high-performance MQDs-based catalysts. [ABSTRACT FROM AUTHOR]

The oriented two-dimensional porous nitrogen-doped carbon embedded with CoS2 and MoS2 nanosheets is a highly efficient bifunctional electrocatalyst. The hierarchical structure ensures fast mass transfer capacity in improving the electrocatalytic activity. And the greatly increased specific surface area is beneficial to expose more electrocatalytically active atoms. For oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) tests in 1 mol/L KOH solution, only 194 and 140 mV overpotential are required to achieve a current density of 10 mA/cm2, respectively. Our research provides an effective strategy for synergizing the individual components in nanostructures for a wide range of electrocatalytic reactions. [ABSTRACT FROM AUTHOR]

Various and critical electrocatalytic processes are involved during the redox reactions in the Li-S batteries, which extremely depend on the surface structure and chemical state. Recently, single-atom concept unlocks a route to maximize the use of surface-active atoms, however, further increasing the density of active site is still strictly limited by the inherent structure that single-atoms are only highly-dispersed on substrate. Herein, we provide a viewpoint that an elaborate facet design with single-crystalline structure engineering can harvest high-density surface active sites, which can significantly boost the electrocatalyst performance for excellent Li-S batteries. Specifically, the single-crystal CoSe2 (scCS) exhibits three-types of terminated (011) facet, efficiently obtaining the surface with a high-rich Co3+—Se bond termination, in contrast with lots of surface grain boundaries and dangling bonds in polycrystalline CoSe2. Surprisingly, the surface active sites concentration can reach more than 69%. As anticipated, it can provide high-density and high-efficient active sites, enormously suppressing the shuttle effect and improving the reaction kinetics via accelerating the conversion and deposition of polysulfides and Li2S. This surface lattice strategy with element terminated mode is a promising approach for designing electrocatalyst effect-based energy system, not merely for Li-S batteries. [ABSTRACT FROM AUTHOR]

Specifically, data for sample D3 in Figure 1 in this Article is the same as data in Figure 2 in[1]; data in Figure 2a in this Article appears identical to data in Figure 4a in[1] with the exception that data in this Article contains additional C-C peaks that seem to have been removed in[1]; data in Figure 7a in this Article appears to be identical to data in Figure 4b in[1] with the exception of being shifted by approximately 6eV. The Editors were not able to obtain current contact details for Youhong Sun, Ming Qian, Baochang Liu, Ke Gao, Yinlong Ma, Mao Wen & Weitao Zheng. The Editors no longer have confidence in the data reported in this Article. [Extracted from the article]

Editor's Note: this Article has been retracted; the Retraction Note is available at https://www.nature.com/articles/10.1038/s41598-022-25431-8 [ABSTRACT FROM AUTHOR]