The simultaneous presence of two active metal centres in diatomic catalysts (DACs) leads to the occurrence of specific interactions between active sites. Such interactions, referred to as long‐range ...interactions (LRIs), play an important role in determining the rate and selectivity of a reaction. The optimal combination of metal centres must be determined to achieve the targeted efficiency. To date, various types of DACs have been synthesised and applied in electrochemistry. However, LRIs have not been systematically summarised. Herein, the regulation, mechanism, and electrocatalytic applications of LRIs are comprehensively summarised and discussed. In addition to the basic information above, the challenges, opportunities, and future development of LRIs in DACs are proposed in order to present an overall view and reference for future research.
Diatomic catalysts have attracted much attention, especially in electrochemistry. However, there have been no comprehensive reviews on long‐range interactions (LRIs) between metallic centres. This Minireview introduces the key aspects of LRIs and highlights opportunities for regulating electrocatalytic mechanisms, thus presenting guidelines for the targeted usage of LRIs.
It is still of great difficulty to develop the non‐platinum catalyst with high catalytic efficiency towards hydrogen evolution reaction via the strategies till now. Therefore, it is necessary to ...develop the new methods of catalyst designing. Here, we put forward the catalyst designed by the electronic metal–support interaction (EMSI), which is demonstrated to be a reliable strategy to find out the high‐efficiency catalyst. We carried out the density functional theory calculation first to design the proper EMSI of the catalyst. We applied the model of M1‐M2‐X (X=C, N, O) during the calculation. Among the catalysts we chose, the EMSI of Rh1TiC, with the active sites of Rh1‐Ti2C2, is found to be the most proper one for HER. The electrochemical experiment further demonstrated the feasibility of the EMSI strategy. The single atomic site catalyst of Rh1‐TiC exhibits higher catalytic efficiency than that of state‐of‐art Pt/C. It achieves a small overpotential of 22 mV and 86 mV at the at the current density of 10 mA cm−2 and 100 mA cm−2 in acid media, with a Tafel slope of 25 mV dec−1 and a mass activity of 54403.9 mA cm−2 mgRh−1 (vs. 192.2 mA cm−2 mgPt−1 of Pt/C). Besides, it also shows appealing advantage in energy saving compared with Pt/C (≈20 % electricity consuming decrease at 2 kA m−2) Therefore, we believe that the strategy of regulating EMSI can act as a possible way for achieving the high catalytic efficiency on the next step of SACs.
The electronic metal–support interaction (EMSI) is closely related to the electronic structure of active sites, which determines the catalytic activity. We put forward a method of designing the EMSI of single‐atomic site catalysts (SACs) to achieve high efficiency. The SACs achieve a lower overpotential and higher mass activity than any other SACs towards hydrogen evolution reaction, demonstrating the benefits of this method.
Solar energy offers an alternative solution to the global community's growing energy demands. Semitransparent organic photovoltaics (ST‐OPVs) have received tremendous attention due to their tunable ...energy levels and rising power conversion efficiency (PCE). Because of its transparency, ST‐OPVs are able to serve as the power‐generating roof of the greenhouse, and color‐tunable walls/windows for modern buildings or façades. With the rapid development of narrow‐bandgap semiconductors to absorb near‐infrared photons, the performances of ST‐OPVs has progressed with PCEs over 12% with average visible transmittances over 20%. Here, recent developments in ST‐OPVs based on narrow‐bandgap donors and non‐fullerene acceptors are reviewed. Several strategies for chemical structures design have been reported to lower bandgaps semiconductor materials. The recent developments of non‐fullerene acceptor structures for ST‐OPVs are categorized into A‐D‐A, A‐π‐D‐π‐A, and A‐DAD‐A by the structure alignment. From device perspectives, the strategies such as ternary blend, distributions of donors and acceptors in active layers, tandem and transparent conductive electrodes for high‐performance ST‐OPVs are summarized. To conclude, some insightful guidelines for future developments in ST‐OPVs from both materials and device points of views are provided.
Semitransparent organic photovoltaics (ST‐OPVs) have been receiving tremendous attention because they of their tunable energy levels and rising power conversion efficiency (PCE). The steady increase of the PCE with high transmittances in the visible range results from improvements of narrow‐bandgap donors and acceptors. Moreover, advanced device structure designs with narrow‐bandgap materials can further push the performance of ST‐OPVs.
Although ether‐based electrolytes have been extensively applied in anode evaluation of batteries, anodic instability arising from solvent oxidability is always a tremendous obstacle to matching with ...high‐voltage cathodes. Herein, by rational design for solvation configuration, the fully coordinated ether‐based electrolyte with strong resistance against oxidation is reported, which remains anodically stable with high‐voltage Na3V2(PO4)2O2F (NVPF) cathode under 4.5 V (versus Na+/Na) protected by an effective interphase. The assembled graphite//NVPF full cells display superior rate performance and unprecedented cycling stability. Beyond that, the constructed full cells coupling the high‐voltage NVPF cathode with hard carbon anode exhibit outstanding electrochemical performances in terms of high average output voltage up to 3.72 V, long‐term cycle life (such as 95 % capacity retention after 700 cycles) and high energy density (247 Wh kg−1). In short, the optimized ether‐based electrolyte enriches systematic options, the ability to maintain oxidative stability and compatibility with various anodes, exhibiting attractive prospects for application.
By rational design of the solvation configuration, a cation–solvent fully coordinated ether‐based electrolyte with strong oxidation resistance up to 4.5 V (versus Na+/Na) was developed and applied in graphite//NVPF and LHC//NVPF full cells which showed superior rate performance and unprecedented cycling stability.
The exploitation of highly efficient carbon dioxide reduction (CO2RR) electrocatalyst for methane (CH4) electrosynthesis has attracted great attention for the intermittent renewable electricity ...storage but remains challenging. Here, N‐heterocyclic carbene (NHC)‐ligated copper single atom site (Cu SAS) embedded in metal–organic framework is reported (2Bn‐Cu@UiO‐67), which can achieve an outstanding Faradaic efficiency (FE) of 81 % for the CO2 reduction to CH4 at −1.5 V vs. RHE with a current density of 420 mA cm−2. The CH4 FE of our catalyst remains above 70 % within a wide potential range and achieves an unprecedented turnover frequency (TOF) of 16.3 s−1. The σ donation of NHC enriches the surface electron density of Cu SAS and promotes the preferential adsorption of CHO* intermediates. The porosity of the catalyst facilitates the diffusion of CO2 to 2Bn‐Cu, significantly increasing the availability of each catalytic center.
A catalyst with N‐heterocyclic carbene‐ligated Cu SAS as the active site, accompanied by many micro‐nano reactors, synergistically promotes the electrochemical synthesis of methane.
Chlorine evolution reaction has been applied in the production since a century ago. After times of evolution, it has been widely realized by the electrocatalytic process on anode nowadays. However, ...the anode applied in production contains a large amount of precious metal, increasing the cost. It is thus an opportunity to apply sub‐nano catalysts in this field. By regulating the tip effect (TE) of the catalyst, it was discovered that the oxidized sub‐nano iridium clusters supported by titanium carbide exhibit much higher efficiency than the single‐atom one, which demonstrates the significance of modifying the electronic interaction. Moreover, it exhibits a ≈20 % decrease of the electricity, ≈98 % selectivity towards chlorine evolution reaction, and high durability of over 350 h. Therefore, this cluster catalyst performs great potential in applying in the practical production and the comprehension of the tip effect on different types of catalysts is also pushed to a higher level.
The tip effect (TE) has not been mentioned enough in catalysts designing, having a large space to explore. Based on the model of oxidized sub‐nano clusters, the TE was regulated and found to be efficient in designing catalysts, making TiC perform a high activity during the chlor‐alkali industry. This cluster system exhibits great potential in applying in the practical production and the comprehension of the TE is also pushed to a higher level.
Covalent organic frameworks (COF) possess a robust and porous crystalline structure, making them an appealing candidate for energy storage. Herein, we report an exfoliated polyimide COF composite ...(P‐COF@SWCNT) prepared by an in situ condensation of anhydride and amine on the single‐walled carbon nanotubes as advanced anode for potassium‐ion batteries (PIBs). Numerous active sites exposed on the exfoliated frameworks and the various open pathways promote the highly efficient ion diffusion in the P‐COF@SWCNT while preventing irreversible dissolution in the electrolyte. During the charging/discharging process, K+ is engaged in the carbonyls of imide group and naphthalene rings through the enolization and π‐K+ effect, which is demonstrated by the DFT calculation and XPS, ex‐situ FTIR, Raman. As a result, the prepared P‐COF@SWCNT anode enables an incredibly high reversible specific capacity of 438 mA h g−1 at 0.05 A g−1 and extended stability. The structural advantage of P‐COF@SWCNT enables more insights into the design and versatility of COF as an electrode.
We prepare a polyimide covalent organic framework composite anode by effective in‐situ condensation of anhydride and amine on the surface of single‐walled carbon nanotubes. The construction of the conductive network accelerates the transport of electron. Dual electroactive sites in the framework, carbonyls and aromatic naphthalene rings, could store more potassium ions by the enolization and π‐K+ effect.
Hard carbon is regarded as a promising anode material for sodium‐ion batteries (SIBs). However, it usually suffers from the issues of low initial Coulombic efficiency (ICE) and poor rate performance, ...severely hindering its practical application. Herein, a flexible, self‐supporting, and scalable hard carbon paper (HCP) derived from scalable and renewable tissue is rationally designed and prepared as practical additive‐free anode for room/low‐temperature SIBs with high ICE. In ether electrolyte, such HCP achieves an ICE of up to 91.2% with superior high‐rate capability, ultralong cycle life (e.g., 93% capacity retention over 1000 cycles at 200 mA g−1) and outstanding low‐temperature performance. Working mechanism analyses reveal that the plateau region is the rate‐determining step for HCP with a lower electrochemical reaction kinetics, which can be significantly improved in ether electrolyte.
A self‐supporting, flexible, additive‐free and scalable hard carbon paper (HCP) derived from tissue is rationally developed, and it achieves outstanding Na‐storage properties in terms of high initial Coulombic efficiency (91.2%), superior high‐rate capability, ultralong cyclic stability, as well as outstanding low‐T performance in ether electrolyte. More significantly, the Na‐storage and capacity attenuation mechanism of the HCP anode is revealed.
Impossible voltage plateau regulation for the cathode materials with fixed active elemental center is a pressing issue hindering the development of Na‐superionic‐conductor (NASICON)‐type ...Na3V2(PO4)2F3 (NVPF) cathodes in sodium‐ion batteries (SIBs). Herein, a high‐entropy substitution strategy, to alter the detailed crystal structure of NVPF without changing the central active V atom, is pioneeringly utilized, achieving simultaneous electronic conductivity enhancement and diffusion barrier reduction for Na+, according to theoretical calculations. The as‐prepared carbon‐free high‐entropy Na3V1.9(Ca,Mg,Al,Cr,Mn)0.1(PO4)2F3 (HE‐NVPF) cathode can deliver higher mean voltage of 3.81 V and more advantageous energy density up to 445.5 Wh kg−1, which is attributed by the diverse transition‐metal elemental substitution in high‐entropy crystalline. More importantly, high‐entropy introduction can help realize disordered rearrangement of Na+ at Na(2) active sites, thereby to refrain from unfavorable discharging behaviors at low‐voltage region, further lifting up the mean working voltage to realize a full Na‐ion storage at the high voltage plateau. Coupling with a hard carbon (HC) anode, HE‐NVPF//HC SIB full cells can deliver high specific energy density of 326.8 Wh kg−1 at 5 C with the power density of 2178.9 W kg−1. This route means the unlikely potential regulation in NASICON‐type crystal with unchangeable active center becomes possible, inspiring new ideas on elevating the mean working voltage for SIB cathodes.
A high‐entropy effect is delicately introduced into fluorophosphate cathode for sodium‐ion batteries by in situ partial substitution of active V central atom, preparing a high‐entropy carbon‐free Na3V1.9(Ca,Mg,Al,Cr,Mn)0.1(PO4)2F3 cathode, suppressing the occurrence of detrimental phase transition process in the low‐voltage region, and further lifting up the mean working voltage of pristine Na3V2(PO4)2F3, enhancing sodium storage behavior, rate capability, and cycle performance.
2D ferroelectric material has emerged as an attractive building block for high‐density data storage nanodevices. Although monolayer van der Waals ferroelectrics have been theoretically predicted, a ...key experimental breakthrough for such calculations is still not realized. Here, hexagonally stacking α‐In2Se3 nanoflake, a rarely studied van der Waals polymorph, is reported to exhibit out‐of‐plane (OOP) and in‐plane (IP) ferroelectricity at room temperature. Ferroelectric multidomain states in a hexagonal α‐In2Se3 nanoflake with uniform thickness can survive to 6 nm. Most strikingly, the electric‐field‐induced polarization switching and hysteresis loop are, respectively, observed down to the bilayer and monolayer (≈1.2 nm) thicknesses, which designates it as the thinnest layered ferroelectric and verifies the corresponding theoretical calculation. In addition, two types of ferroelectric nanodevices employing the OOP and IP polarizations in 2H α‐In2Se3 are developed, which are applicable for nonvolatile memories and heterostructure‐based nanoelectronics/optoelectronics.
The thinnest layered ferroelectric is demonstrated for the first time at room temperature. The semiconducting hexagonal α‐In2Se3 nanoflakes exhibit out‐of‐plane and in‐plane ferroelectricity that are closely intercorrelated. The polarization switching and hysteresis loops can be realized in the thickness as thin as ≈2.3 nm (bilayer) and ≈1.2 nm (monolayer). Two types of ferroelectric switchable devices are proposed to show the potential application in nonvolatile memories.
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