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The room‐temperature sodium‐sulfur (RT Na‐S) batteries have been seriously hindered in their practical application due to the sluggish redox kinetics and incomplete conversion of polysulfides. In this study, a structure‐determined Keggin‐type heteropolyvanadotungstate of H5PW10V2O40·30H2O (PW10V2) is engineered and reveal its catalytic mechanism in RT Na‐S system. With the assistance of precise V sites and highly reversible multi‐electron redox properties, PW10V2 as a bidirectional molecular catalyst expedites the complete conversions between polysulfides and the insoluble sodium sulfide, while undergoing the reversible transformation between its reduced and oxidized states. Furthermore, PW10V2 with multicenter active sites can capture polysulfides efficiently. Consequently, the cell with the constructed PW10V2‐based modified separator achieves the perdurable cyclability up to 4000 loops even at 10 C toward an exceptionally low capacity decay rate of 0.012% per cycle, far surpassing those of current state‐of‐the‐art RT Na‐S batteries that employ the functional materials based on separator. This work first demonstrates the underlying electrochemical reaction processes of polyoxometalate‐based functional materials, which guides solving the challenging issues related to sodium polysulfides in RT Na‐S batteries. [ABSTRACT FROM AUTHOR]

To fully comprehend the correlation between the structure and photocatalytic performance of copper clusters, an atomically precise model is imperative. Nevertheless, the challenge of precisely controlling the electronic structure of these clusters persists. Herein, by accurately manipulating experimental conditions, three fourteen-nuclear thiolate copper clusters of [Cu14(SCPh)12(P(Ph-F)3)6](NO3)2 (Cu14) [Cu14(μ6-O)(SCPh)12(P(Ph-F)3)6] (O@Cu14) and [Cu14(SCPh)12(P(Ph-F)3)6][Cu14(μ8-O)(SCPh)12(P(Ph-F)3)6](NO3)2 ([Cu14][O@Cu14]), are demonstrated. Especially in O@Cu14 and [Cu14][O@Cu14], the subunit of the Cu8 cage center facilitates the insertion of a central oxygen atom. Although researchers have predicted that the Cu8 cage center can accommodate a central oxygen atom, to date, there have been no reports of copper clusters with such sub-structural units. Moreover, the impact of central oxygen atom insertion, particularly on the catalytic performance of copper clusters, remains an unresolved issue. When these copper clusters are loaded onto the surface of hydroxyl-functionalized g-C3N4 nanosheets (g-C3N4(OH)), the resulting composites exhibit excellent H2-production performance compared to that of g-C3N4(OH). Moreover, the significantly enhanced catalytic activity of O@Cu14@g-C3N4(OH) compared to Cu14@g-C3N4(OH) demonstrates that the insertion of oxygen atoms in the Cu8 cage can markedly affect the electronic structure of copper clusters, thereby enhancing the photocatalytic activity. In the case of [Cu14][O@Cu14]@g-C3N4(OH), the matching effect between two copper clusters' HOMO–LUMO energy levels additionally enhances the photocatalytic activity, leading to a value-added effect. This study not only confirms the long-standing prediction that the Cu8 center can accommodate an oxygen atom but also demonstrates a novel central atom regulation strategy to obtain highly active copper clusters as photocatalysts. [ABSTRACT FROM AUTHOR]

In the reaction of oxidizing 5-hydroxymethylfurfural (HMF), attaining high efficiency and selectivity in the conversion of HMF into DFF presents a challenge due to the possibility of forming multiple products. Polyoxometalates are considered highly active catalysts for HMF oxidation. However, the over-oxidation of products poses a challenge, leading to decreased purity and yield. In this work, metal–organic framework-derived Fe3O4/C and Co3O4/C were designed as carriers for the vanadium-substituted Keggin-type polyoxomolybdate H5PMo10V2O40·35H2O (PMo10V2). In this complex system, spinel oxides can effectively adsorb HMF molecules and cooperate with PMo10V2 to catalyze the aerobic oxidation of HMF. As a result, the as-prepared PMo10V2@Fe3O4/C and PMo10V2@Co3O4/C catalysts can achieve efficient conversion of HMF into DFF with almost 100% selectivity. Among them, PMo10V2@Fe3O4/C exhibits a higher conversion rate (99.1%) under milder reaction conditions (oxygen pressure of 0.8 MPa). Both catalysts exhibited exceptional stability and retained their activity and selectivity even after undergoing multiple cycles. Studies on mechanisms by in situ diffuse reflectance infrared Fourier transform spectroscopy and X-ray photoelectron spectroscopy revealed that the V5+ and Mo6+ in PMo10V2, together with the metal ions in the spinel oxides, act as active centers for the catalytic conversion of HMF. Therefore, it is proposed that PMo10V2 and M3O4/C (M = Fe, Co) cooperatively catalyze the transformation of HMF into DFF via a proton-coupled electron transfer mechanism. This study offers an innovative approach for designing highly selective and recyclable biomass oxidation catalysts. [ABSTRACT FROM AUTHOR]

In order to improve the heat dissipation performance and study the factors affecting the heat dissipation effect of a two-dimensional ordered porous structure, a thermal analysis of the radiator in the power module of a DC charging pile was carried out. Based on the thermal analysis of the grid-type radiator, the square-hole radiator is subjected to a thermal analysis, the heat dissipation performance of the two radiators is compared, and the factors affecting the heat dissipation effect of the square-hole radiator are explored. Research shows that the heat dissipation effect of the square-hole radiator, which represents a twodimensional ordered porous structure, is better than that of the grid-type radiator. The factors affecting the heat dissipation effect of the square-hole radiator are mainly related to the height of the radiator and are positively related to the heat dissipation effect of the radiator.

The propulsion of photocatalytic hydrogen (H2) production is limited by the rational design and regulation of catalysts with precise structures and excellent activities. In this work, the [MoOS3]2− unit is introduced into the CuI clusters to form a series of atomically‐precise MoVI−CuI bimetallic clusters of [Cu6(MoOS3)2(C6H5(CH2)S)2(P(C6H4−R)3)4] ⋅ xCH3CN (R=H, CH3, or F), which show high photocatalytic H2 evolution activities and excellent stability. By electron push‐pull effects of the surface ligand, highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels of these MoVI−CuI clusters can be finely tuned, promoting the resultant visible‐light‐driven H2 evolution performance. Furthermore, MoVI−CuI clusters loaded onto the surface of magnetic Fe3O4 carriers significantly reduced the loss of catalysts in the collection process, efficiently addressing the recycling issues of such small cluster‐based catalyst. This work not only highlights a competitively universal approach on the design of high‐efficiency cluster photocatalysts for energy conversion, but also makes it feasible to manipulate the catalytic performance of clusters through a rational substituent strategy. [ABSTRACT FROM AUTHOR]

Platinum (Pt) catalysts are the most practical electrocatalysts; however, their low abundance and high cost severely limit their large-scale applications. Efficient recovery is a key issue to be resolved before the use of Pt-based electrocatalysts can be broadly extended. Herein, the newly designed polyoxometalate [PtII(NH3)4]2[Mo8O26] (Mo8Pt) acts as an ideal recycling medium for renewable and highly effective Pt electrocatalysts. Starting from Mo8Pt, by a facile reduction reaction, the formed Pt/Mo2C/Mo2N@C-N electrocatalyst shows superior electrocatalytic activity as compared to commercial Pt/C (20%) under both acidic and alkaline conditions. Notably, the reaction of Pt/Mo2C/Mo2N@C-N in H2O2 solution can regenerate Mo8Pt for Pt renew-ability. It is also demonstrated that the Pt electrocatalyst can be used for at least five rounds of recycling and regeneration, showing its efficiency and stability as well as its effectiveness. This work highlights a recycling medium strategy to the new generation of renewable Pt-based catalysts. [ABSTRACT FROM AUTHOR]

It has been demonstrated that polyoxometalates (POMs) have strong anchoring abilities with efficient catalysis of lithium polysulfides (LiPSs). However, the severe aggregation that buries the effective active sites of POMs along with poor electrical conductivity limits the practical application of POMs in lithium sulfur batteries (LSBs). In our strategy, we utilized reduced graphene oxide (rGO) to support a POM catalyst entrapped in a MIL-88A(FeCo) network with a hollow shell skeleton as the sulfur host material. H4PW11VO40 (PW11V) with optimal vanadium atom implantation ensures the ruggedness and integrity of the hollow structure, which is conducive to achieving high sulfur loading as well as accommodating the volume change of the sulfur cathode during the charging and discharging process. Importantly, PW11V can capture polysulfides through firm chemical adsorption and accelerate redox reactions of LiPS conversion by effective electrochemical catalysis. Furthermore, the satisfactory electrical conductivity of rGO provides access for electrons to reach the interface of PW11V and polysulfides and trigger Li–S conversion reactions. Thus, the constructed PW11V-based sulfur cathode exhibited a superior specific capacity of 905 mA h g−1 after 100 cycles under 0.2 C and long cycling life with a capacity recession rate of 0.046% for each cycle upon 500 cycles under 3 C. This research reveals the effect of vanadium atom substitution of POMs on the cycling performance of a sulfur cathode and affords insight for developing high-performance LSBs. [ABSTRACT FROM AUTHOR]

Synthesis of catalysts with high activity for hydrogen evolution reaction (HER) has been a hot topic in electrocatalysis. In this paper, using MIL-88A(Fe) metal-organic complex, polyoxometalate (POM) and H2PtCl6 as starting materials, hierarchic and low Pt0-loading micro-rods (denoted as Pt-POMFe, i.e. Pt-PW12Fe or Pt-PMo12Fe) have been synthesized, in which the Pt0 nanoparticles can be stabilized by POM. The Pt-PW12Fe micro-rod containing [PW12O40]3- polyoxoanion component (0.30% Pt0-loading) which retains the spindle structure of its parent MIL-88A(Fe) exhibits a low overpotential of 28 mV at current density of 10 mA·cm−2 for HER that is close to the electrocatalytic effect of commercial Pt/C (ca. 20% Pt0-loading). Such high electrocatalytic reactivity is mainly caused by the synergistic effect of the three components of POM, Pt0, and Fe3O4@C. The structure effectively increases the active sites of the catalyst and improves its conductivity and stability. The Pt-POMFe catalyst extends a new family of MOF-POM functional materials and provides a new concept to the design and synthesis of highly-efficient and low-cost electrocatalyst for hydrogen production. [ABSTRACT FROM AUTHOR]

In this study, Pt-substituted polyoxometalate was first modified on the surface of commercially available TiO2, forming an efficient photocatalyst with high reactivity for hydrogen evolution. During the photocatalytic process, Pt-polyoxometalates not only increase the mobility rate of electrons but also improve the separation efficiency of photoinduced electrons and holes. After photoreduction, the in situ generated Pt0 species are anchored on the surface of polyoxometalate anion, which prevents further agglomeration. Then, the in situ formed Pt0 species and polyoxometalates synergistically promote the efficiency of photoinduced electron transfer from TiO2 to the protons adsorbed on the Pt0 surface. Although the content of Pt0 in the nanocomposite is only 0.6%, the photocatalytic hydrogen production rate reaches 5.6 mmol g−1 h−1 and remains stable at 4.5 mmol g−1 h−1 after the continuous catalytic process. Due to the modification of TiO2 by Pt-substituted polyoxometalate, this nanocomposite represents a practical model that possesses highly efficient photoelectric conversion performance. The presented work not only extends the family of new TiO2-polyoxometalate-based materials but also takes a further step toward the practical application of commercial TiO2 in photocatalytic hydrogen production. [ABSTRACT FROM AUTHOR]

In the reaction of oxidizing 5-hydroxymethylfurfural (HMF), attaining high efficiency and selectivity in the conversion of HMF into DFF presents a challenge due to the possibility of forming multiple products. Polyoxometalates are considered highly active catalysts for HMF oxidation. However, the over-oxidation of products poses a challenge, leading to decreased purity and yield. In this work, metal-organic framework-derived Fe 3 O 4 /C and Co 3 O 4 /C were designed as carriers for the vanadium-substituted Keggin-type polyoxomolybdate H 5 PMo 10 V 2 O 40 ·35H 2 O (PMo 10 V 2 ). In this complex system, spinel oxides can effectively adsorb HMF molecules and cooperate with PMo 10 V 2 to catalyze the aerobic oxidation of HMF. As a result, the as-prepared PMo 10 V 2 @Fe 3 O 4 /C and PMo 10 V 2 @Co 3 O 4 /C catalysts can achieve efficient conversion of HMF into DFF with almost 100% selectivity. Among them, PMo 10 V 2 @Fe 3 O 4 /C exhibits a higher conversion rate (99.1%) under milder reaction conditions (oxygen pressure of 0.8 MPa). Both catalysts exhibited exceptional stability and retained their activity and selectivity even after undergoing multiple cycles. Studies on mechanisms by in situ diffuse reflectance infrared Fourier transform spectroscopy and X-ray photoelectron spectroscopy revealed that the V 5+ and Mo 6+ in PMo 10 V 2 , together with the metal ions in the spinel oxides, act as active centers for the catalytic conversion of HMF. Therefore, it is proposed that PMo 10 V 2 and M 3 O 4 /C (M = Fe, Co) cooperatively catalyze the transformation of HMF into DFF via a proton-coupled electron transfer mechanism. This study offers an innovative approach for designing highly selective and recyclable biomass oxidation catalysts.

The propulsion of photocatalytic hydrogen (H 2 ) production is limited by the rational design and regulation of catalysts with precise structures and excellent activities. In this work, the [MoOS 3 ] 2- unit is introduced into the Cu I clusters to form a series of atomically-precise Mo VI -Cu I bimetallic clusters of [Cu 6 (MoOS 3 ) 2 (C 6 H 5 (CH 2 )S) 2 (P(C 6 H 4 -R) 3 ) 4 ] ⋅ xCH 3 CN (R=H, CH 3 , or F), which show high photocatalytic H 2 evolution activities and excellent stability. By electron push-pull effects of the surface ligand, highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels of these Mo VI -Cu I clusters can be finely tuned, promoting the resultant visible-light-driven H 2 evolution performance. Furthermore, Mo VI -Cu I clusters loaded onto the surface of magnetic Fe 3 O 4 carriers significantly reduced the loss of catalysts in the collection process, efficiently addressing the recycling issues of such small cluster-based catalyst. This work not only highlights a competitively universal approach on the design of high-efficiency cluster photocatalysts for energy conversion, but also makes it feasible to manipulate the catalytic performance of clusters through a rational substituent strategy., (© 2023 Wiley-VCH GmbH.)

It has been demonstrated that polyoxometalates (POMs) have strong anchoring abilities with efficient catalysis of lithium polysulfides (LiPSs). However, the severe aggregation that buries the effective active sites of POMs along with poor electrical conductivity limits the practical application of POMs in lithium sulfur batteries (LSBs). In our strategy, we utilized reduced graphene oxide (rGO) to support a POM catalyst entrapped in a MIL-88A(FeCo) network with a hollow shell skeleton as the sulfur host material. H 4 PW 11 VO 40 (PW 11 V) with optimal vanadium atom implantation ensures the ruggedness and integrity of the hollow structure, which is conducive to achieving high sulfur loading as well as accommodating the volume change of the sulfur cathode during the charging and discharging process. Importantly, PW 11 V can capture polysulfides through firm chemical adsorption and accelerate redox reactions of LiPS conversion by effective electrochemical catalysis. Furthermore, the satisfactory electrical conductivity of rGO provides access for electrons to reach the interface of PW 11 V and polysulfides and trigger Li-S conversion reactions. Thus, the constructed PW 11 V-based sulfur cathode exhibited a superior specific capacity of 905 mA h g -1 after 100 cycles under 0.2 C and long cycling life with a capacity recession rate of 0.046% for each cycle upon 500 cycles under 3 C. This research reveals the effect of vanadium atom substitution of POMs on the cycling performance of a sulfur cathode and affords insight for developing high-performance LSBs.

The main challenge for sodium/potassium ion storage is to find the suitable host materials to accommodate the larger-sized Na + /K + and conquer the sluggish chemical kinetics. Herein, by selenation of polyoxometalate in electrospinning fiber, a novel MoO 2 /MoSe 2 heterostructure embedded in one-dimensional (1D) N,P-doped carbon nanofiber (MoO 2 /MoSe 2 @NPC) is rationally constructed to show distinct enhancement of rate performance and cycle life for sodium ion batteries (SIBs) and potassium ion batteries (PIBs). The 1D skeleton of MoO 2 /MoSe 2 @NPC decreases the diffusion pathway of Na + /K + , and the doping of N/P heteroatoms in carbon fiber creates abundant active sites and provides good reachability for Na + /K + transportation. MoSe 2 nanosheets grow in the bulk phase of MoO 2 via in situ local phase transformation to achieve effective and firm heterointerfaces. Especially, the exposure extent of heterointerfaces can be controlled by treatment temperature during the preparation process, and the optimized heterointerfaces result in an ideal synergic effect between MoO 2 and MoSe 2 . DFT calculations confirm that the internal electric field in the heterogeneous interface guides the electron transfer from MoO 2 to MoSe 2 , combined with strong adsorption capacity toward sodium/potassium, facilitating ion/electron transfer kinetics. It is confirmed that the MoO 2 /MoSe 2 @NPC anode for SIBs delivers 382 mA h g -1 under 0.1 A g -1 upon 200 cycles; meanwhile, a reversible capacity of 266 mA h g -1 is maintained even under 2 A g -1 after 2000 cycles. For PIBs, it can reach up to 216 mA h g -1 in the 200th cycle and still retain 125 mA h g -1 after 2000 cycles under 1 A g -1 . This study opens up a new interface manipulation strategy for the design of anode materials to boost fast Na + /K + storage kinetics.

For the design of atom-precise copper nanoclusters, besides the exploration of their aesthetic cage-like architectures, their structural modulation and potential applications are being extensively explored. Herein, an atom-precise 20-core copper(I)-alkynyl nanocluster (UJN-Cu20) protected by ethinyloestradiol ligands issynthesized. By virtue of outer-shell hydroxyl groups, UJN-Cu20 could be uniformly modified on the surface of TiO 2 nanosheets via hydrogen bonding interactions, thus forming an efficient nanocomposite photocatalyst for hydrogen evolution. By constructing a Z-scheme heterojunction, the photocatalytic hydrogen evolution activity of the nanocomposite (13 mmol g -1 h -1 ) significantly improved as compared to that of TiO 2 nanosheets (0.4 mmol g -1 h -1 ). As a narrow bandgap cocatalyst, UJN-Cu20 is confirmed to effectively inhibit the electron-hole recombination on the surface of the TiO 2 nanosheet, which provides a new concept for the design of copper cluster-assisted effective photocatalysts.

In this study, Pt-substituted polyoxometalate was first modified on the surface of commercially available TiO 2 , forming an efficient photocatalyst with high reactivity for hydrogen evolution. During the photocatalytic process, Pt-polyoxometalates not only increase the mobility rate of electrons but also improve the separation efficiency of photoinduced electrons and holes. After photoreduction, the in situ generated Pt 0 species are anchored on the surface of polyoxometalate anion, which prevents further agglomeration. Then, the in situ formed Pt 0 species and polyoxometalates synergistically promote the efficiency of photoinduced electron transfer from TiO 2 to the protons adsorbed on the Pt 0 surface. Although the content of Pt 0 in the nanocomposite is only 0.6%, the photocatalytic hydrogen production rate reaches 5.6 mmol g -1 h -1 and remains stable at 4.5 mmol g -1 h -1 after the continuous catalytic process. Due to the modification of TiO 2 by Pt-substituted polyoxometalate, this nanocomposite represents a practical model that possesses highly efficient photoelectric conversion performance. The presented work not only extends the family of new TiO 2 -polyoxometalate-based materials but also takes a further step toward the practical application of commercial TiO 2 in photocatalytic hydrogen production.