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Manipulating the crystallographic orientation of zinc deposition is recognized as an effective approach to address zinc dendrites and side reactions for aqueous zinc-ion batteries (ZIBs). We introduce 2-methylimidazole (Mlz) additive in zinc sulfate (ZSO) electrolyte to achieve vertical electrodeposition with preferential orientation of the (100) and (110) crystal planes. Significantly, the zinc anode exhibited long lifespan with 1500 h endurance at 1 mA cm -2 and an excellent 400 h capability at a depth of discharge (DOD) of 34% in Zn||Zn battery configurations, while in Zn||MnO 2 battery assemblies, a capacity retention of 68.8% over 800 cycles is attained. Theoretical calculation reveals that the strong interactions between Mlz and (002) plane impeding its growth, while Zn atoms exhibit lower migration energy barrier and superior mobility on (100) and (110) crystal planes guaranteed the heightened mobility of zinc atoms on the (100) and (110) crystal planes, thus ensuring their superior ZIB performance than that with only ZSO electrolyte, which offers a route for designing next-generation high energy density ZIB devices.

As a versatile energy carrier, H 2 is considered as one of the most promising sources of clean energy to tackle the current energy crisis and environmental concerns, which can be produced from photocatalytic water splitting. However, solar-driven photocatalytic H 2 production from pure water in the absence of sacrificial reagents remains a great challenge. Herein, we demonstrate that the incorporation of Ru single atoms (SAs) into ZnIn 2 S 4 (Ru-ZIS) can enhance the light absorption, reduce the energy barriers for water dissociation, and construct a channel (Ru-S) for separating photogenerated electron-hole pairs, as a result of a significantly enhanced photocatalytic water splitting process. Impressively, the productivity of H 2 reaches 735.2 μmol g -1 h -1 under visible light irradiation in the absence of sacrificial agents. The apparent quantum efficiency (AQE) for H 2 evolution reaches 7.5% at 420 nm, with a solar-to-hydrogen (STH) efficiency of 0.58%, which is much higher than the value of natural synthetic plants (∼0.10%). Moreover, Ru-ZIS exhibits steady productivity of H 2 even after exposure to ambient conditions for 330 days. This work provides a unique strategy for constructing charge transfer channels to promote the separation of photogenerated electron-hole pairs, which may motivate the fundamental researches on catalyst design for photocatalysis and beyond., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Co-published by University of Science and Technology of China and American Chemical Society.)

Liquid-solid contact electrification (CE) is essential to diverse applications. Exploiting its full implementation requires an in-depth understanding and fine-grained control of charge carriers (electrons and/or ions) during CE. Here, we decouple the electrons and ions during liquid-solid CE by designing binary superhydrophobic surfaces that eliminate liquid and ion residues on the surfaces and simultaneously enable us to regulate surface properties, namely work function, to control electron transfers. We find the existence of a linear relationship between the work function of superhydrophobic surfaces and the as-generated charges in liquids, implying that liquid-solid CE arises from electron transfer due to the work function difference between two contacting surfaces. We also rule out the possibility of ion transfer during CE occurring on superhydrophobic surfaces by proving the absence of ions on superhydrophobic surfaces after contact with ion-enriched acidic, alkaline, and salt liquids. Our findings stand in contrast to existing liquid-solid CE studies, and the new insights learned offer the potential to explore more applications., (© 2024. The Author(s).)

Electrochemical ethanol oxidation is crucial to directly convert a biorenewable liquid fuel with high energy density into electrical energy, but it remains an inefficient reaction even with the best catalysts. To boost ethanol oxidation, developing multimetallic nanoalloy has emerged as one of the most effective strategies, yet faces a challenge in the rational engineering of multimetallic active-site ensembles at atomic-level. Herein, starting from typical PtCu nanocrystals, an atomic Sn diffusion strategy is developed to construct well-defined Pt 47 Sn 12 Cu 41 octopod nanoframes, which is enclosed by high-index facets of n (111)-(111), such as {331} and {221}. Pt 47 Sn 12 Cu 41 achieves a high mass activity of 3.10 A mg -1 Pt and promotes the C-C bond breaking and oxidation of poisonous CO intermediate, representing a state-of-the-art electrocatalyst toward ethanol oxidation in acidic electrolyte. Density functional theory （DFT） calculations have confirmed that the introduction of Sn improves the electroactivity by uplifting the d-band center through the s-p-d coupling. Meanwhile, the strong binding of ethanol and the reduced energy barrier of CO oxidation guarantee a highly efficient ethanol oxidation process with improved Faradic efficiency of C1 products. This work offers a promising strategy for constructing novel multimetallic nanoalloys tailored by atomic metal sites as the efficient electrocatalysts., (© 2024 Wiley‐VCH GmbH.)

The manipulation of excitation modes and resultant emission colors in luminescent materials holds pivotal importance for encrypting information in anti-counterfeiting applications. Despite considerable achievements in multimodal and multicolor luminescent materials, existing options generally suffer from static monocolor emission under fixed external stimulation, rendering them vulnerability to replication. Achieving dynamic multimodal luminescence within a single material presents a promising yet challenging solution. Here, we report the development of a phosphor exhibiting dynamic multicolor photoluminescence (PL) and photo-thermo-mechanically responsive multimodal emissions through the incorporation of trace Mn 2+ ions into a self-activated CaGa 4 O 7 host. The resulting phosphor offers adjustable emission-color changing rates, controllable via re-excitation intervals and photoexcitation powers. Additionally, it demonstrates temperature-induced color reversal and anti-thermal-quenched emission, alongside reproducible elastic mechanoluminescence (ML) characterized by high mechanical durability. Theoretical calculations elucidate electron transfer pathways dominated by intrinsic interstitial defects and vacancies for dynamic multicolor emission. Mn 2+ dopants serve a dual role in stabilizing nearby defects and introducing additional defect levels, enabling flexible multi-responsive luminescence. This developed phosphor facilitates evolutionary color/pattern displays in both temporal and spatial dimensions using readily available tools, offering significant promise for dynamic anticounterfeiting displays and multimode sensing applications., (© 2024. The Author(s).)

The development of efficient and stable catalysts for hydrogen production from electrolytic water in a wide pH range is of great significance in alleviating the energy crisis. Herein, Pt nanoparticles (NPs) anchored on the vacancy of high entropy rare earth oxides (HEREOs) were prepared for the first time for highly efficient hydrogen production by water electrolysis. The prepared Pt-(LaCeSmYErGdYb)O showed excellent electrochemical performances, which require only 12, 57, and 77 mV to achieve a current density of 100 mA cm -2 in 0.5 M H 2 SO 4 , 1.0 M KOH, and 1.0 M PBS environments, respectively. In addition, Pt-(LaCeSmYErGdYb)O has successfully worked at 400 mA cm -2 @ 60 °C for 100 h in 0.5 M H 2 SO 4 , presenting the high mass activity of 37.7 A mg -1 Pt and turnover frequency (TOF) value of 38.2 s -1 @ 12 mV, which is far superior to the recently reported hydrogen evolution reaction (HER) catalysts. Density functional theory (DFT) calculations have revealed that the interactions between Pt and HEREO have optimized the electronic structures for electron transfer and the binding strength of intermediates. This further leads to optimized proton binding and water dissociation, supporting the highly efficient and robust HER performances in different environments. This work provides a new idea for the design of efficient RE-based electrocatalysts.

Electrocatalytic nitrate reduction reaction (NO 3 RR) toward ammonia synthesis is recognized as a sustainable strategy to balance the global nitrogen cycle. However, it still remains a great challenge to achieve highly efficient ammonia production due to the complex proton-coupled electron transfer process in NO 3 RR. Here, the controlled synthesis of RuMo alloy nanoflowers (NFs) with unconventional face-centered cubic (fcc) phase and hexagonal close-packed/fcc heterophase for highly efficient NO 3 RR is reported. Significantly, fcc RuMo NFs demonstrate high Faradaic efficiency of 95.2% and a large yield rate of 32.7 mg h -1 mg cat -1 toward ammonia production at 0 and -0.1 V (vs reversible hydrogen electrode), respectively. In situ characterizations and theoretical calculations have unraveled that fcc RuMo NFs possess the highest d-band center with superior electroactivity, which originates from the strong Ru─Mo interactions and the high intrinsic activity of the unconventional fcc phase. The optimal electronic structures of fcc RuMo NFs supply strong adsorption of key intermediates with suppression of the competitive hydrogen evolution, which further determines the remarkable NO 3 RR performance. The successful demonstration of high-performance zinc-nitrate batteries with fcc RuMo NFs suggests their substantial application potential in electrochemical energy supply systems., (© 2024 Wiley‐VCH GmbH.)

Despite of urgent needs for highly stable and efficient electrochemical water-splitting devices, it remains extremely challenging to acquire highly stable oxygen evolution reaction (OER) electrocatalysts under harsh industrial conditions. Here, a successful in situ synthesis of FeCoNiMnCr high-entropy alloy (HEA) and high-entropy oxide (HEO) heterocatalysts via a Cr-induced spontaneous reconstruction strategy is reported, and it is demonstrated that they deliver excellent ultrastable OER electrocatalytic performance with a low overpotential of 320 mV at 500 mA cm -2 and a negligible activity loss after maintaining at 100 mA cm -2 for 240 h. Remarkably, the heterocatalyst holds outstanding long-term stability under harsh industrial condition of 6 m KOH and 85 °C at a current density of as high as 500 mA cm -2 over 500 h. Density functional theory calculations reveal that the formation of the HEA-HEO heterostructure can provide electroactive sites possessing robust valence states to guarantee long-term stable OER process, leading to the enhancement of electroactivity. The findings of such highly stable OER heterocatalysts under industrial conditions offer a new perspective for designing and constructing efficient high-entropy electrocatalysts for practical industrial water splitting., (© 2024 Wiley‐VCH GmbH.)

Electrocatalytic carbon dioxide reduction reaction (CO 2 RR) toward value-added chemicals/fuels has offered a sustainable strategy to achieve a carbon-neutral energy cycle. However, it remains a great challenge to controllably and precisely regulate the coordination environment of active sites in catalysts for efficient generation of targeted products, especially the multicarbon (C 2+ ) products. Herein we report the coordination environment engineering of metal centers in coordination polymers for efficient electroreduction of CO 2 to C 2+ products under neutral conditions. Significantly, the Cu coordination polymer with Cu-N 2 S 2 coordination configuration (Cu-N-S) demonstrates superior Faradaic efficiencies of 61.2% and 82.2% for ethylene and C 2+ products, respectively, compared to the selective formic acid generation on an analogous polymer with the Cu-I 2 S 2 coordination mode (Cu-I-S). In situ studies reveal the balanced formation of atop and bridge *CO intermediates on Cu-N-S, promoting C-C coupling for C 2+ production. Theoretical calculations suggest that coordination environment engineering can induce electronic modulations in Cu active sites, where the d-band center of Cu is upshifted in Cu-N-S with stronger selectivity to the C 2+ products. Consequently, Cu-N-S displays a stronger reaction trend toward the generation of C 2+ products, while Cu-I-S favors the formation of formic acid due to the suppression of C-C couplings for C 2+ pathways with large energy barriers.

Bimetallic PtRu are promising electrocatalysts for hydrogen oxidation reaction in anion exchange membrane fuel cell, where the activity and stability are still unsatisfying. Here, PtRu nanowires were implanted with a series of oxophilic metal atoms (named as i-M-PR), significantly enhancing alkaline hydrogen oxidation reaction (HOR) activity and stability. With the dual doping of In and Zn atoms, the i-ZnIn-PR/C shows mass activity of 10.2 A mg Pt+Ru -1 at 50 mV, largely surpassing that of commercial Pt/C (0.27 A mg Pt -1 ) and PtRu/C (1.24 A mg Pt+Ru -1 ). More importantly, the peak power density and specific power density are as high as 1.84 W cm -2 and 18.4 W mg Pt+Ru -1 with a low loading (0.1 mg cm -2 ) anion exchange membrane fuel cell. Advanced experimental characterizations and theoretical calculations collectively suggest that dual doping with In and Zn atoms optimizes the binding strengths of intermediates and promotes CO oxidation, enhancing the HOR performances. This work deepens the understanding of developing novel alloy catalysts, which will attract immediate interest in materials, chemistry, energy and beyond., (© 2024. The Author(s).)

Zinc-nitrate batteries can integrate energy supply, ammonia electrosynthesis, and sewage disposal into one electrochemical device. However, current zinc-nitrate batteries still severely suffer from the limited energy density and poor rechargeability. Here, we report the synthesis of tetraphenylporphyrin (tpp)-modified heterophase (amorphous/crystalline) rhodium-copper alloy metallenes (RhCu M-tpp). Using RhCu M-tpp as a bifunctional catalyst for nitrate reduction reaction (NO 3 RR) and ethanol oxidation reaction in neutral solution, a highly rechargeable and low-overpotential zinc-nitrate/ethanol battery is successfully constructed, which exhibits outstanding energy density of 117364.6 Wh kg -1 cat , superior rate capability, excellent cycling stability of ~400 cycles, and potential ammonium acetate production. Ex/in situ experimental studies and theoretical calculations reveal that there is a molecule-metal relay catalysis in NO 3 RR over RhCu M-tpp that significantly facilitates the ammonia selectivity and reaction kinetics via a low energy barrier pathway. This work provides an effective design strategy of multifunctional metal-based catalysts toward the high-performance zinc-based hybrid energy systems., Competing Interests: Competing interests statement:The authors declare no competing interest.

Developing highly efficient and stable hydrogen production catalysts for electrochemical water splitting (EWS) at industrial current densities remains a great challenge. Herein, we proposed a heterostructure-induced-strategy to optimize the metal-support interaction (MSI) and the EWS activity of Ru-Ni 3 N/NiO. Density functional theory (DFT) calculations firstly predicted that the Ni 3 N/NiO-heterostructures can improve the structural stability, electronic distributions, and orbital coupling of Ru-Ni 3 N/NiO compared to Ru-Ni 3 N and Ru-NiO, which accordingly decreases energy barriers and increases the electroactivity for EWS. As a proof-of-concept, the Ru-Ni 3 N/NiO catalyst with a 2D Ni 3 N/NiO-heterostructures nanosheet array, uniformly dispersed Ru nanoparticles, and strong MSI, was successfully constructed in the experiment, which exhibited excellent HER and OER activity with overpotentials of 190 mV and 385 mV at 1000 mA cm -2 , respectively. Furthermore, the Ru-Ni 3 N/NiO-based EWS device can realize an industrial current density (1000 mA cm -2 ) at 1.74 V and 1.80 V under alkaline pure water and seawater conditions, respectively. Additionally, it also achieves a high durability of 1000 h (@ 500 mA cm -2 ) in alkaline pure water., (© 2023 Wiley-VCH GmbH.)

Solar energy utilization is of great significance to current challenges of the energy crisis and environmental pollution, which benefit the development of the global community to achieve carbon neutrality goals. Hydrogen energy is also treated as a good candidate for future energy supply since its combustion not only supplies high-density energy but also shows no pollution gas. In particular, photocatalytic water splitting has attracted increasing research as a promising method for H 2 production. Recently, single-atom (SA) photocatalysts have been proposed as a potential solution to improve catalytic efficiency and lower the costs of photocatalytic water splitting for H 2 generation. Owing to the maximized atom utilization rate, abundant surface active sites, and tunable coordination environment, SA photocatalysts have achieved significant progress. This review reviews developments of advanced SA photocatalysts for H 2 generation regarding the different support materials. The recent progress of titanium dioxide, metal-organic frameworks, two-dimensional carbon materials, and red phosphorus supported SA photocatalysts are carefully discussed. In particular, the material designs, reaction mechanisms, modulation strategies, and perspectives are highlighted for realizing improved solar-to-energy efficiency and H 2 generation rate. This work will supply significant references for future design and synthesis of advanced SA photocatalysts., (© 2023 Wiley-VCH GmbH.)

Designing efficient and durable bifunctional catalysts for 5-hydroxymethylfurfural (HMF) oxidation reaction (HMFOR) and hydrogen evolution reaction (HER) is desirable for the co-production of biomass-upgraded chemicals and sustainable hydrogen, which is limited by the competitive adsorption of hydroxyl species (OH ads ) and HMF molecules. Here, we report a class of Rh-O 5 /Ni(Fe) atomic site on nanoporous mesh-type layered double hydroxides with atomic-scale cooperative adsorption centers for highly active and stable alkaline HMFOR and HER catalysis. A low cell voltage of 1.48 V is required to achieve 100 mA cm -2 in an integrated electrolysis system along with excellent stability (>100 h). Operando infrared and X-ray absorption spectroscopic probes unveil that HMF molecules are selectively adsorbed and activated over the single-atom Rh sites and oxidized by in situ-formed electrophilic OH ads species on neighboring Ni sites. Theoretical studies further demonstrate that the strong d-d orbital coupling interactions between atomic-level Rh and surrounding Ni atoms in the special Rh-O 5 /Ni(Fe) structure can greatly facilitate surface electronic exchange-and-transfer capabilities with the adsorbates (OH ads and HMF molecules) and intermediates for efficient HMFOR and HER. We also reveal that the Fe sites in Rh-O 5 /Ni(Fe) structure can promote the electrocatalytic stability of the catalyst. Our findings provide new insights into catalyst design for complex reactions involving competitive adsorptions of multiple intermediates.

Electrochemical nitrate reduction reaction (NO 3 RR) to ammonia has been regarded as a promising strategy to balance the global nitrogen cycle. However, it still suffers from poor Faradaic efficiency (FE) and limited yield rate for ammonia production on heterogeneous electrocatalysts, especially in neutral solutions. Herein, we report one-pot synthesis of ultrathin nanosheet-assembled RuFe nanoflowers with low-coordinated Ru sites to enhance NO 3 RR performances in neutral electrolyte. Significantly, RuFe nanoflowers exhibit outstanding ammonia FE of 92.9% and yield rate of 38.68 mg h -1 mg cat -1 (64.47 mg h -1 mg Ru -1 ) at -0.30 and -0.65 V (vs. reversible hydrogen electrode), respectively. Experimental studies and theoretical calculations reveal that RuFe nanoflowers with low-coordinated Ru sites are highly electroactive with an increased d-band center to guarantee efficient electron transfer, leading to low energy barriers of nitrate reduction. The demonstration of rechargeable zinc-nitrate batteries with large-specific capacity using RuFe nanoflowers indicates their great potential in next-generation electrochemical energy systems.

For current single-atom catalysts (SACs), modulating the coordination environments of rare-earth (RE) single atoms with complex electronic orbital and flexible chemical states is still limited. Herein, cerium (Ce) SAs supported on a P, S, and N co-doped hollow carbon substrate (Ce SAs/PSNC) for the oxygen reduction reaction (ORR) are reported. The as-prepared Ce SAs/PSNC possesses a half-wave potential of 0.90 V, a turnover frequency value of 52.2 s -1 at 0.85 V, and excellent stability for the ORR, which exceeds the commercial Pt/C and most recent SACs. Ce SAs/PSNC-based liquid zinc-air batteries (ZABs) exhibit a high and stable open-circuit voltage of 1.49 V and a maximum power density of 212 mW cm -2 . As the catalyst of the air cathode, it also displays remarkable performance in flexible electronic devices. Theoretical calculations reveal that the introduction of S and P sites induces significant electronic modulations to the Ce SA active sites. The P and S dopings promote the electroactivity of Ce SAs and improve the overall site-to-site electron transfer within the Ce SAs/PSNC. This work offers a unique perspective for modulating RE-based SACs in a complex coordination environment toward superior electrocatalysis and broad applications in energy conversion and storage devices., (© 2023 Wiley-VCH GmbH.)

Transition metal (TM) single atom catalysts (SACs) are of great potential for photocatalytic H 2 production because of their abundant catalytic active sites and cost-effectiveness. As a promising support material, red phosphorus (RP) based SACs are still rarely investigated. In this work, we have carried out systematic theoretical investigations by anchoring TM atoms (Fe, Co, Ni, Cu) on RP for efficient photocatalytic H 2 generation. Our density functional theory (DFT) calculations have revealed that 3d orbitals of TM locate close to the Fermi level to guarantee efficient electron transfer for photocatalytic performances. Compared with pristine RP, the introduction of single atom TM on the surface exhibit narrowed bandgaps, resulting in easier spatial separation for photon-generated charge carriers and an extended photocatalytic absorption window to the NIR range. Meanwhile, the H 2 O adsorptions are also highly preferred on the TM single atoms with strong electron exchange, which benefits the subsequent water-dissociation process. Due to the optimized electronic structure, the activation energy barrier of water-splitting has been remarkably reduced in RP-based SACs, revealing their promising potential for high-efficiency H 2 production. Our comprehensive explorations and screening of novel RP-based SACs will offer a good reference for further designing novel photocatalysts for high-efficiency H 2 generation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Lu, Sun, Wu, Lu, Chen, Chan, Wong and Huang.)

Ruthenium chalcogenide is a highly promising catalytic system as a Pt alternative for hydrogen evolution reaction (HER). However, well-studied ruthenium selenide (RuSe 2 ) still exhibits sluggish HER kinetics in alkaline media due to the inappropriate adsorption strength of H and H 2 O. Herein, xx report a new design of Cu-doped Ru/RuSe 2 heterogeneous nanosheets (NSs) with optimized H and H 2 O adsorption strength for highly efficient HER catalysis in alkaline media. Theoretical calculations reveal that the superior HER performance is attributed to a synergistic effect of the unique heterointerfaced structure and Cu doping, which not only optimizes the electronic structure with a suitable d-band center to suppress proton overbinding but also alleviates the energy barrier with enhanced H 2 O adsorption. As a result, Cu-doped heterogeneous Ru/RuSe 2 NSs exhibit a small overpotential of 23 mV at 10 mA cm -2 , a low Tafel slope of 58.5 mV dec -1 and a high turnover frequency (TOF) value of 0.88 s -1 at 100 mV for HER in alkaline media, which is among the best catalysts in noble metal-based electrocatalysts toward HER. The present Cu-doped Ru/RuSe 2 NSs interface catalyst is very stable for HER by showing no activity decay after 5000-cycle potential sweeps. This work heralds that heterogeneous interface modulation opens up a new strategy for the designing of more efficient electrocatalysts., (© 2023 Wiley-VCH GmbH.)

A cross-coupling reaction via the dehydrogenative route over heterogeneous solid atomic catalysts offers practical solutions toward an economical and sustainable elaboration of simple organic substrates. The current utilization of this technology is, however, hampered by limited molecular definition of many solid catalysts. Here, we report the development of Cu-M dual-atom catalysts (where M = Co, Ni, Cu, and Zn) supported on a hierarchical USY zeolite to mediate efficient dehydrogenative cross-coupling of unprotected phenols with amine partners. Over 80% isolated yields have been attained over Cu-Co-USY, which shows much superior reactivity when compared with our Cu 1 and other Cu-M analogues. This amination reaction has hence involved simple and non-forceful reaction condition requirements. The superior reactivity can be attributed to (1) the specifically designed bimetallic Cu-Co active sites within the micropore for "co-adsorption-co-activation" of the reaction substrates and (2) the facile intracrystalline (meso/micropore) diffusion of the heterocyclic organic substrates. This study offers critical insights into the engineering of next-generation solid atomic catalysts with complex reaction steps.

Currently, scientists have devoted great efforts to finding effective treatments to combat COVID-19 infections. Although noble metal nanoparticles are able to realize protein modifications, their interactions with the protein are still unclear from the atomic perspective. To supply a general understanding, in this work, we have carried out theoretical calculations to investigate the interaction between protein segments (RBD1, RBD2, RBD3) of SARS-Cov-2 spike protein and a series of noble metal (Au, Ag, Cu, Pd, Pt) surfaces regarding the binding strength, protein orientations, and electronic modulations. In particular, the Au surface has shown the strongest binding preferences for the protein segments, which induces electron transfer between the Au and receptor-binding domain (RBD) segments. This further leads to the polarization of segments for virus denaturation. This work has offered a direct visualization of protein interactions with noble metal surfaces from the atomic level, which will benefit anti-virus material developments in the future., Competing Interests: The authors declare no competing interests., (© 2023 The Authors.)

It is important to understand the polymorph transition and crystal-amorphous phase transition in In 2 Se 3 to tap the potential of this material for resistive memory storage. By monitoring layer-by-layer growth of β-In 2 Se 3 during molecular beam epitaxy (MBE), we are able to identify a cyclical order-disorder transition characterized by a periodic alternation between a glassy-like metastable subunit cell film consisting of n < 5 sublayers ( n th layers = the number of subunit cell layers), and a highly crystalline β-In 2 Se 3 at n = 5 layers. The glassy phase shows an odd-even alternation between the indium-cluster layer ( n = 1, 3) and an In-Se solid solution ( n = 2, 4), which suggests the ability of In and Se atoms to diffuse, aggregate, and intermix. These dynamic natures of In and Se atoms contribute to a defect-driven memory resistive behavior in current-voltage sweeps that is different from the ferroelectric switching of α-In 2 Se 3 .

The control of multimetallic ensembles at the atomic-level is challenging, especially for high-entropy alloys (HEAs) possessing five or more elements. Herein, the one-pot synthesis of hexagonal-close-packed (hcp) PtRhBiSnSb high-entropy intermetallic (HEI) nanoplates with intrinsically isolated Pt, Rh, Bi, Sn, and Sb atoms is reported, to boost the electrochemical oxidation of liquid fuels. Taking advantage of these combined five metals, the well-defined PtRhBiSnSb HEI nanoplates exhibit a remarkable mass activity of 19.529, 15.558, and 7.535 A mg -1 Pt+Rh toward the electrooxidation of methanol, ethanol, and glycerol in alkaline electrolytes, respectively, representing a state-of-the-art multifunctional electrocatalyst for alcohol oxidation reactions. In particular, the PtRhBiSnSb HEI achieves record-high methanol oxidation reaction (MOR) activity in an alkaline environment. Theoretical calculations demonstrate that the introduction of the fifth metal Rh enhances the electron-transfer efficiency in PtRhBiSnSb HEI nanoplates, which contributes to the improved oxidation capability. Meanwhile, robust electronic structures of the active sites are achieved due to the synergistic protections from Bi, Sn, and Sb sites. This work offers significant research advances in developing well-defined HEA with delicate control over compositions and properties., (© 2022 Wiley-VCH GmbH.)

For electrochemical CO 2 reduction to HCOOH, an ongoing challenge is to design energy efficient electrocatalysts that can deliver a high HCOOH current density (J HCOOH ) at a low overpotential. Indium oxide is good HCOOH production catalyst but with low conductivity. In this work, we report a unique corn design of In 2 O 3-x @C nanocatalyst, wherein In 2 O 3-x nanocube as the fine grains dispersed uniformly on the carbon nanorod cob, resulting in the enhanced conductivity. Excellent performance is achieved with 84% Faradaic efficiency (FE) and 11 mA cm -2 J HCOOH at a low potential of - 0.4 V versus RHE. At the current density of 100 mA cm -2 , the applied potential remained stable for more than 120 h with the FE above 90%. Density functional theory calculations reveal that the abundant oxygen vacancy in In 2 O 3-x has exposed more In 3+ sites with activated electroactivity, which facilitates the formation of HCOO* intermediate. Operando X-ray absorption spectroscopy also confirms In 3+ as the active site and the key intermediate of HCOO* during the process of CO 2 reduction to HCOOH., (© 2022. The Author(s).)

Realizing the rational design of perovskite oxides with controllable compositions and nanostructures remains a tremendous challenge for the development of efficient electrocatalysts. Herein, a ligand-assisted synthetic strategy to fabricate perovskite oxides LaCo 1- x Fe x O 3 with yolk-shell nanostructures is developed. Benefiting from the unique structural and compositional merits, LaCo 0.75 Fe 0.25 O 3 exhibits an overpotential of 310 mV at a current density of 10 mA cm -2 and long-term stability of 100 h for the oxygen evolution reaction. In situ Raman spectroscopy demonstrates that Fe substitution facilitates the pre-oxidation of Co sites and induces the surface reconstruction into active Co oxyhydroxides at a relatively lower applied potential, guaranteeing excellent catalytic performances. Density functional theory calculations unravel that the appropriate introduction of Fe into perovskite LaCoO 3 leads to the improved electroactivity and durability of the catalyst for the oxygen evolution reaction (OER). Fe-3d orbitals show a pinning effect on Co-3d orbitals to maintain the stable valence state of Co sites at the low overpotential of the OER. Furthermore, Zn-air batteries (ZABs) assembled with LaCo 0.75 Fe 0.25 O 3 display a high open circuit potential of 1.47 V, superior energy density of 905 Wh kg -1   Zn , and excellent stability in a large temperature range. This work supplies novel insights into the future developments of perovskite-based electrocatalysts., (© 2022 Wiley-VCH GmbH.)

With super strong penetrability, high-energy X-rays can be applied to probe the inner structure of target objects under nondestructive situations. Scintillation materials can down-convert X-rays into visible light, enabling the reception of photon signals and photoelectric conversion by common sensing arrays such as photomultiplier tubes and amorphous-Si photodiode matrixes. All-inorganic perovskite nanocrystals are emerging photovoltaic and scintillation materials, with tremendous light-conversion efficiency and tunable luminous properties, exhibiting great potential for high-quality X-ray imaging. Recent advancements in nanotechnology further accelerate the performance improvement of scintillation materials. In this review, we will provide a comprehensive overview of novel all-inorganic perovskite nano-scintillators in terms of potential applications in low-dose X-ray medical radiography. Compared with conventional scintillators, the merits/drawbacks, challenges, and scintillation performance control will be the focus of this article., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Rare-earth (RE) solid-state halide electrolytes have been extensively studied recently in the field of lithium (Li) ion all-solid-state batteries (ASSBs) due to their excellent electrochemical performances. Herein, a new RE-based solid halide electrolyte Li 3 HoBr 6 (LHB) has been synthesized and exhibits high Li ion conductivity up to mS cm -1 at room temperature. Theoretical calculations have identified four different Li ion migration pathways, in which the out-of-plane pathways are much more favorable than the direct in-plane pathways. In addition, LHB has a wider electrochemical window in comparison to a sulfide solid electrolyte and good deformability. The LHB-based Li-sulfur ASSB assembled by cold pressing can exhibit good cycling stability with high Coulombic efficiency, which shows that LHB has potential application in ASSBs.

Copper-based catalysts are efficient for CO 2 reduction affording commodity chemicals. However, Cu(i) active species are easily reduced to Cu(0) during the CO 2 RR, leading to a rapid decay of catalytic performance. Herein, we report a hybrid-catalyst that firmly anchors 2D-Cu metallic dots on F-doped Cu x O nanoplates (Cu x OF), synthesized by electrochemical-transformation under the same conditions as the targeted CO 2 RR. The as-prepared Cu/Cu x OF hybrid showed unusual catalytic activity towards the CO 2 RR for CH 3 COO - generation, with a high FE of 27% at extremely low potentials. The combined experimental and theoretical results show that nanoscale hybridization engenders an effective s,p-d coupling in Cu/Cu x OF, raising the d-band center of Cu and thus enhancing electroactivity and selectivity for the acetate formation. This work highlights the use of electronic interactions to bias a hybrid catalyst towards a particular pathway, which is critical for tuning the activity and selectivity of copper-based catalysts for the CO 2 RR., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Rare earth (RE) based halide solid electrolytes (HEs) are recently considered as research hotspots in the field of all-solid-state batteries (ASSBs). The RE-based HEs possess high ionic conductivity, credible deformability, and good stability, which can bring excellent electrochemical performances for ASSBs. However, the conventional synthetic methods of RE HEs are a mechanochemical process and co-melting strategy, both approaches require expensive raw materials and sophisticated equipment. Therefore, a lot of research work is required to promote the preparation methods for these promising SSEs in ASSBs. Thus, a vacuum evaporation-assisted synthesis method is developed for the massive synthesis of HEs. The as-prepared Li 3 HoBr 6 (LHB) has a high lithium-ion conductivity close to the mS cm -1 level and the LHB-based Li-Se ASSBs can be assembled by cold pressing. Theoretical calculations have revealed that the Li migrations are highly preferred in Li 3 HoBr 6 owing to the low energy cost and high tolerance of stable structure. The tetrahedral and octahedral pathways are responsible for Li migrations in short and long ranges, respectively. The results show that the LHB-based Li-Se battery has good stability and rate performance, indicating that LHB has potential application in the field of ASSBs., (© 2021 Wiley-VCH GmbH.)

Mechanoluminescence (ML) is a striking optical phenomenon that is achieved through mechanical to optical energy conversion. Here, a series of Li 1 -x Na x NbO 3 : Pr 3+ (x = 0, 0.2, 0.5, 0.8, 1.0) ML materials have been developed. In particular, due to the formation of heterostructure, the synthesized Li 0.5 Na 0.5 NbO 3 : Pr 3+ effectively couples the trap structures and piezoelectric property to realize the highly repeatable ML performance without traditional preirradiation process. Furthermore, the ML performances measured under sunlight irradiation and preheating confirm that the ML properties of Li 0.5 Na 0.5 NbO 3 : Pr 3+ can be ascribed to the dual modes of luminescence mechanism, including both trap-controllable and self-recoverable modes. In addition, DFT calculations further confirm that the doping of Na + ions in LiNbO 3 leads to electronic modulations by the formation of the heterostructures, which optimizes the trap distributions and concentrations. These modulations improve the electron transfer efficiency to promote ML performances. This work has supplied significant references for future design and synthesis of efficient ML materials for broad applications., (© 2021 Wiley-VCH GmbH.)

Although high-index facets (HIF) endows excellent catalytic activity through undercoordinated sites with strain effect, current characterizations techniques still cannot unravel the detailed strain distributions to understand the origins of electroactivity. Nevertheless, theoretical principles to quantify the structural features and their effects on catalytic activity improvements on HIFs are still lacking, which renders the experimental efforts laborious. In this work, we explore the quantification of surface structural features and establish a database of atomic strain distributions for the late-transition metal HIF nanoparticle models. The surface reactivities of the nanoparticles have been examined by adsorption energy calculations and their correlations with structural features are observed. Our proposed theoretical principles on surface characterizations of high-index facets nanomaterials will promote the design and synthesis of efficient transition metal based electrocatalysts., (© 2021 Wiley-VCH GmbH.)

Alloying is a general strategy for modulating the electronic structures of catalyst materials. Compared to more common solid-solution alloys, intermetallic alloys feature well-defined atomic arrangements and provide the unique platform for studying the structure-performance correlations. It is, unfortunately, synthetically challenging to prepare the nanostructures of intermetallic alloys for catalysis research. In this contribution, we prepare intermetallic Pd 3 Bi nanocrystals of a uniform size via a facile solvothermal method. These nanocrystals can phase-transform into solid solution alloy via thermal annealing while retaining a similar composition and size. In 0.1 M KHCO 3 aqueous solution, the intermetallic Pd 3 Bi can selectively reduce CO 2 to formate with high selectivity (≈100 %) and stability even at <-0.35 V versus reversible hydrogen electrode, whereas the solid solution alloy has limited formate selectivity of <60 %. Such unique phase-dependence is understood via theoretical simulations showing that the crystallographic ordering of Pd and Bi atoms within intermetallic alloys can suppress CO poisoning and enhance the *OCHO adsorption during electrochemical CO 2 reduction to formate., (© 2021 Wiley-VCH GmbH.)

We report a new form of catalyst based on ferromagnetic hexagonal-close-packed (hcp) Co nanosheets (NSs) for selective CO 2 RR to ethanal, CH 3 CHO. In all reduction potentials tested from -0.2 to -1.0 V (vs RHE) in 0.5 M KHCO 3 solution, the reduction yields ethanal as a major product and ethanol/methanol as minor products. At -0.4 V, the Faradaic efficiency (FE) for ethanal reaches 60% with current densities of 5.1 mA cm -2 and mass activity of 3.4 A g -1 (total FE for ethanal/ethanol/methanol is 82%). Density functional theory (DFT) calculations suggest that this high CO 2 RR selectivity to ethanal on the hcp Co surface is attributed to the unique intralayer electron transfer, which not only promotes [OC-CO]* coupling but also suppresses the complete hydrogenation of the coupling intermediates to ethylene, leading to highly selective formation of CH 3 CHO.

Due to the synergistic effect of Cr 3+ dopant levels and defect state, the luminescence intensity and decay time in LaAlO 3 are remarkably enhanced, and the emission wavelength from deep-red (Cr 3+ as the luminescent center) to NIR-II/III (defect states as the luminescent center) can be effectively tuned via an energy transfer process.

Two-dimensional (2D) nanomaterials are attracting much attention due to their excellent electronic and optical properties. Here, we report the first experimental preparation of two free-standing mercurated graphyne nanosheets via the interface-assisted bottom-up method, which integrates both the advantages of metal center and graphyne. The continuous large-area nanosheets derived from the chemical growth show the layered molecular structural arrangement, controllable thickness and enhanced π-conjugation, which result in their stable and outstanding broadband nonlinear saturable absorption (SA) properties (at both 532 and 1064 nm). The passively Q-switched (PQS) performances of these two nanosheets as the saturable absorbers are comparable to or higher than those of the state-of-the-art 2D nanomaterials (such as graphene, black phosphorus, MoS 2 , γ-graphyne, etc.). Our results illustrate that the two metallated graphynes could act not only as a new class of 2D carbon-rich materials, but also as inexpensive and easily available optoelectronic materials for device fabrication., (© 2021 Wiley-VCH GmbH.)

Efficient noble-metal free electrocatalyst for oxygen evolution reaction (OER) is critical for large-scale hydrogen production via water splitting. Inspired by Nature's oxygen evolution cluster in photosystem II and the highly efficient artificial OER catalyst of NiFe layered double hydroxide (LDH), we designed an electrostatic 2D-2D assembly route and successfully synthesized a 2D LDH(+)-Birnessite(-) hybrid. The as-constructed LDH(+)-Birnessite(-) hybrid catalyst showed advanced catalytic activity and excellent stability towards OER under a close to industrial hydrogen production condition (85 °C and 6 M KOH) for more than 20 h at the current densities larger than 100 mA cm -2 . Experimentally, we found that besides the enlarged interlayer distance, the flexible interlayer NiFe LDH(+) also modulates the electronic structure of layered MnO 2 , and creates an electric field between NiFe LDH(+) and Birnessite(-), wherein OER occurs with a greatly decreased overpotential. DFT calculations confirmed the interlayer LDH modulations of the OER process, attributable to the distinct electronic distributions and environments. Upshifting the Fe-3d orbitals in LDH promotes electron transfer from the layered MnO 2 to LDH, significantly boosting up the OER performance. This work opens a new way to fabricate highly efficient OER catalyst for industrial water oxidation., (© 2021 Wiley-VCH GmbH.)

Designing bifunctional catalysts capable of driving the electrochemical hydrogen evolution reaction (HER) and also H 2 evolution via the hydrolysis of hydrogen storage materials such as ammonia borane (AB) is of considerable practical importance for future hydrogen economies. Herein, we systematically examined the effect of tensile lattice strain in CoRu nanoalloys supported on carbon quantum dots (CoRu/CQDs) on hydrogen generation by HER and AB hydrolysis. By varying the Ru content, the lattice parameters and Ru-induced lattice strain in the CoRu nanoalloys could be tuned. The CoRu 0.5 /CQDs catalyst with an ultra-low Ru content (1.33 wt.%) exhibited excellent catalytic activity for HER (η=18 mV at 10 mA cm -2 in 1 M KOH) and extraordinary activity for the hydrolysis of AB with a turnover frequency of 3255.4 mol ( H 2 )  mol -1 (Ru)  min -1 or 814.7 mol ( H 2 )  mol -1 (cat)  min -1 at 298 K, respectively, representing one of the best activities yet reported for AB hydrolysis over a ruthenium alloy catalyst. Moreover, the CoRu 0.5 /CQDs catalyst displayed excellent stability during each reaction, including seven alternating cycles of HER and AB hydrolysis. Theoretical calculations revealed that the remarkable catalytic performance of CoRu 0.5 /CQDs resulted from the optimal alloy electronic structure realized by incorporating small amounts of Ru, which enabled fast interfacial electron transfer to intermediates, thus benefitting H 2 evolution kinetics. Results support the development of new and improved catalysts HER and AB hydrolysis., (© 2020 Wiley-VCH GmbH.)

Electrochemical conversion of nitrogen (N 2 ) into value-added ammonia (NH 3 ) is highly desirable yet formidably challenging due to the extreme inertness of the N 2 molecule, which makes the development of a robust electrocatalyst prerequisite. Herein, a new class of bullet-like M-Te (M = Ru, Rh, Ir) glassy porous nanorods (PNRs) is reported as excellent electrocatalysts for N 2 reduction reaction (NRR). The optimized IrTe 4 PNRs present superior activity with the highest NH 3 yield rate (51.1 µg h -1 mg -1 cat. ) and Faraday efficiency (15.3%), as well as long-term stability of up to 20 consecutive cycles, making them among the most active NRR electrocatalysts reported to date. Both the N 2 temperature-programmed desorption and valence band X-ray photoelectron spectroscopy data show that the strong chemical adsorption of N 2 is the key for enhancing the NRR and suppressing the hydrogen evolution reaction of IrTe 4 PNRs. Density functional theory calculations comprehensively identify that the superior adsorption strength of IrTe 4 adsorptions originates from the synergistic collaboration between electron-rich Ir and the highly electroactive surrounding Te atoms. The optimal adsorption of both N 2 and H 2 O in alkaline media guarantees the superior consecutive NRR process. This work opens a new avenue for designing high-performance NRR electrocatalysts based on glassy materials., (© 2020 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Oxygen vacancies are usually considered to be beneficial in catalytic conversion of polysulfides in lithium-sulfur batteries. Now it is demonstrated that the conversion of polysulfides was hindered by oxygen vacancies on ultrathin niobic acid. The inferior performance induced by the oxygen vacancy was mainly attributed to the decreased electric conductivity as well as the weakened adsorption of polysulfides on the catalyst surface. This work shows that the care should be taken when designing a new catalyst for the lithium-sulfur battery using a defect-engineering strategy., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Here we describe the Cp*Rh(iii)-catalyzed cascade arylfluorination reactions of α-diazoketoesters with arylboronic acids and N-fluorobenzenesulfonimide for one-pot C(sp3)-C(aryl) and C(sp3)-F bond formation. The arylfluorination reaction can be accomplished with remarkable chemo- and regioselectivity. Our mechanistic investigation showed that the Rh-catalyzed arylfluorination of diazoacetates occurred by (1) transmetalation of arylboronic acids to form an arylrhodium(iii) complex, (2) coupling of diazomalonates with the arylrhodium(iii) complex to form carbene-rhodium, (3) migratory carbene insertion to form a diketonato-rhodium(iii) complex - probably via rearrangement of the putative σ-alkylrhodium(iii) complex, and (4) electrophilic fluorination of the diketonato-rhodium to form the α-aryl-α-fluoromalonates.

Unravelling upconversion (UC) energy transfer mechanisms is significant for designing novel efficient anti-Stokes phosphors. We have studied the correlation of different lanthanide dopants within Er 3+ -self-sensitized core@shell upconversion nanoparticles (UCNPs). Here, our focus will be on high-concentration dopants that are able to sufficiently produce the clustering effect, especially within the interplay between Er 3+ and Yb 3+ . We demonstrate that whatever the amount of the self-sensitizer (e.g., Er 3+ ), abnormal absorption enhancement will occur as long as Yb 3+ clusters are present. This effect originates from the substantial energy transfer between Yb 3+ -Yb 3+ clusters despite the increased energy transfer from Yb 3+ to Er 3+ . Therefore, the energy transfer efficiency is still constrained. However, we conversely used one of the aforementioned quench-paths of UC energy transfer to easily transfer the energy from the in-shell shell layer to the in-core area with the assistance of the energy potential reservoir, which was given by the homogeneous core@shell band offset at the interface region. Indirectly, we actualize the Er 3+ UC luminescence with self-sensitization through an extended energy transfer path. This work provides a solid support and analytic theory for unraveling the energy transfer mechanism from recent works on Er 3+ self-sensitized UC luminescence.