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Developing effective strategy to passivate surface defects in quantum dots (QDs) is critical to achieving high‐efficiency and long‐life perovskite light‐emitting diodes (LEDs). Here, the supramolecular interaction underpinning of organic‐inorganic components is exploited and a facile method is proposed to generate multiple‐hydrogen‐bonded supramolecular‐perovskite crystal structures on QD surfaces by introducing O‐Tolylbiguanide (O‐Tg) during QD synthesis, enabling bright, conductive, and water‐resistant CsPbI3 QDs. Compared with commonly used oleic acid and oleylamine ligands, the biguanide functional group in O‐Tg not only forms multiple hydrogen bond interactions with lead halide octahedra passivating both bridging‐ and terminal‐halogen ion defects, but also compatibly occupies the A‐site position stabilizing the crystal structure simultaneously. With fewer nonradiative defects and introduced hydrophobic benzene rings preventing eroding of polar molecules, CsPbI3 QDs exhibit remarkable photoluminescence quantum yields of 96%, and their film can be submerged in water for 30 h without degrading. The corresponding LEDs display a high external quantum efficiency (21.2%) and offer superior operational stability with a lifetime (T90) of 25 h at a constant current density as high as 50 mA cm−2. [ABSTRACT FROM AUTHOR]

Perovskite‐based light‐emitting diodes (PeLEDs) with a mixed halide composition can be used to obtain the "pure red" emission, i.e., in the 620–650 nm range, required for high‐definition displays. However, fast halide ion migration induces phase separation in these materials under electric fields, resulting in poor spectral stability and low efficiency. Herein, a method for producing mixed halide CsPbI3‐xBrx quantum dots (QDs) is reported in which ion migration is suppressed. The mixed halide composition is first achieved by anion exchange between CsPbI3 QDs and hydrobromic acid (HBr), during that the bromine ions efficiently passivate the iodine vacancies of the QDs. The original oleic acid ligands are then exchanged for 1‐dodecanethiol (1‐DT), which suppresses halide ion migration via the strong binding of the sulfhydryl group with the QD surface. PeLEDs based on these QDs exhibit a pure‐red electroluminescence (EL) peak at 637 nm, a maximum external quantum efficiency (EQE) of 21.8% with an average value of 20.4%, a peak luminance of 2653 cd m−2, and low EQE decease with increasing luminance. The EL spectrum of these devices is stable even at 6.7 V and they have an EQE half‐life of 70 min at an initial luminance of 150 cd m−2. [ABSTRACT FROM AUTHOR]

Lithium metal has been recognized as the most promising anode material due to its high capacity and low electrode potential. However, the high reactivity, infinite volume variation, and uncontrolled dendrites growth of Li during long‐term cycling severely limit its practical applications. To address these issues, herein, a novel 3D Al/Mg/Li alloy (denoted as AM‐Li) anode is designed and constructed by a facile smelting‐rolling strategy, which improves the surface stability, electrochemical cycling stability, and rate capability in lithium metal batteries. Specifically, the optimized AM‐Li|AM‐Li symmetric cell exhibits low polarization voltage (< 20 mV) and perfect cycling stability at 1 mA cm−2‐1 mAh cm−2 for more than 1600 h. Moreover, the AM‐Li|NCM811 full cell exhibits superior rate capability up to 5 C and excellent cyclability for 100 cycles at 0.5 C with a high capacity retention of 90.8%. The realization of lithium‐poor or lithium‐free anode materials will be a major development trend of anode materials in the future. Therefore, the research shows that the construction of 3D alloy framework is beneficial to improve the cycling stability of Li anodes by suppressing the volume expansion effect and Li dendrite growth, which will promote the further development of lithium‐poor metal anodes. [ABSTRACT FROM AUTHOR]

Constructing earth‐abundant water splitting electrocatalysts performing platinum‐like activity is promising for the hydrogen economy but still a challenging task. Herein, the ultrafine CoMnP nanocrystals confined in amorphous carbon nanosheets are designed and implemented by a topological transformation strategy from layer double hydroxide/carbon interconnected structures in one single nanosheet. The unique interconnected structure favors the exposure of active sites and enables stronger electronic coupling effect between the two phases. Experimental results and density functional theory simulations reveal that the surrounding amorphous carbon and Mn dopants synergistically enable better electron delocalization capacity of Co sites, potentially providing enhanced conductivity and optimal reaction energetics during hydrogen evolution. The as‐prepared catalyst exhibits hydrogen evolution reaction performances superior to that of Pt/C under alkaline media with an overpotential of 114 mV at 100 mA cm–2. This work highlights the rational fabrication of transition metal‐based electrocatalysts via spatially confined growth for efficient water electrolysis. [ABSTRACT FROM AUTHOR]

The devise and fabrication of highly efficient electrocatalysts have momentous practical significance for the development of future hydrogen energy systems. However, their potential uses in support construction are not well studied. In this work, a highly efficient electrocatalyst is developed for the hydrogen evolution reaction by anchoring single Pt atoms and clusters into functional amorphous pentlandite Fe5Ni4S8 (or FNS) to yield Pt–FNS composites. Amorphous FNS still provides great conductivity to the composites, thereby promoting rapid charge transfer. The presence of abundant defects in Pt–FNS composite catalysts induces pleasant atomic dispersion and anchoring of Pt species. In addition, the formation of single Pt atoms combined with clusters and low‐Pt‐loading improves the utilization of Pt and reduces the cost. The turnover frequency analysis suggests Pt–FNS systems possess significant unit catalytic activity. The synergetic catalytic effect issued from high conductivity, abundant active sites and elevated intrinsic activity forms Pt–FNS systems with efficient pH‐universal catalytic activity. The systems exhibit low overpotentials of only 30, 65, and 98 mV at 10 mA cm−2 under acidic, alkaline, and neutral conditions, respectively. In sum, the proposed route looks promising for the fabrication of new electrocatalysts with improved properties. [ABSTRACT FROM AUTHOR]

Controlling the transport and minimizing charge carrier trapping at interfaces is crucial for the performance of various optoelectronic devices. Here, how electronic properties of stable, abundant, and easy‐to‐synthesized carbon dots (CDs) are controlled via the surface chemistry through a chosen ratio of their precursors citric acid and ethylenediamine are demonstrated. This allows to adjust the work function of indium tin oxide (ITO) films over the broad range of 1.57 eV, through deposition of thin CD layers. CD modifiers with abundant amine groups reduce the ITO work function from 4.64 to 3.42 eV, while those with abundant carboxyl groups increase it to 4.99 eV. Using CDs to modify interfaces between metal oxide (SnO2 and ZnO) films and active layers of solar cells and light‐emitting diodes (LEDs) allows to significantly improve their performance. Power conversion efficiency of CH3NH3PbI3 perovskite solar cells increases from 17.3% to 19.5%; the external quantum efficiency of CsPbI3 perovskite quantum dot LEDs increases from 4.8% to 10.3%; and that of CdSe/ZnS quantum dot LEDs increases from 8.1% to 21.9%. As CD films are easily fabricated in air by solution processing, the approach paves the way to a simplified manufacturing of large‐area and low‐cost optoelectronic devices. [ABSTRACT FROM AUTHOR]

The emerging single-atom field spans single-atom catalysis in chemistry and single-atom manipulation in physics up to the state-of-the-art characterization via imaging and spectroscopy. These interdisciplinary progresses have been interacted closely with the development of materials science, underscoring the principle that the single atom excels as the smallest functional material. This simple concept not only permits to reinvent our understanding of the nature of materials, but also promises unambiguously to have a great impact on other physical sciences. [ABSTRACT FROM AUTHOR]

In situ formation of gel polymer electrolytes (GPE) has been a promising candidate to address individual limitations of liquid/solid electrolytes and interfacial stability. However, the controllable conversion of liquid electrolyte (LE) precursor to GPE remains a great challenge with lower lithium‐ion transport, which is far from the demand for fast‐charging properties. Herein, a strategy of gradient polymerization of forming GPE is pioneered, stabilizing the electrolyte/electrode interface with an accelerated Li+ migration feature. As demonstrated by theoretical simulations and visualization experiment results, the formation mechanism of GPE via a partial inhibitory mechanism of Lithium nitrate (LiNO3) to control the solvent polymerization is comprehensively investigated, exhibiting the preferential interaction between nitrate anion (NO3−) and the Lewis acidic site in lithium bis(fluorosulfonyl)imide (LiFSI). Consequently, a stable amorphous GPE with high Li+ conductivity (5.10 mS cm−1) and an inorganic solid electrolyte interphase (SEI)‐dominate layer derived from spectroscopical measurements are achieved on the graphite electrode surface. The as‐prepared lithium iron phosphate (LFP)||graphite pouch cell stabilizes the capacity of 109.80 mAh g−1 (capacity retention: 80.02%) after 715 cycles at 5 C/1 C (charge/discharge), corresponding to the energy density of 277.64 Wh kg−1. This work provides a facile but practical approach to designing a highly stable GPE for fast‐charging lithium‐ion batteries. [ABSTRACT FROM AUTHOR]

The electrooxidation of urea holds great potential for converting urea from wastewater into hydrogen, contributing to environmental protection and sustainable energy production. This necessitates the development of highly efficient and stable catalysts for the urea oxidation reaction (UOR). In this study, a NiCoCr‐LDH/NF (nickel‐cobalt‐chromium layered double hydroxide/nickel foam) electrode is successfully synthesized via a simple hydrothermal method, demonstrating excellent electrocatalytic performance with a low work potential of 1.38 V at a high current density of 100 mA cm−2. In situ, Raman spectra analysis revealed that the incorporation of chromium (Cr) facilitated the generation of active γ‐NiOOH species and catalyst reconstruction. Density functional theory (DFT) simulations confirmed that the lower formation energy of γ‐NiOOH is due to the weakened interaction of O─H bonds because of a narrow energy range of hybridization between O‐2pz orbitals and H‐1s orbitals. The introduction of Cr also improved the adsorption energy of urea molecules and its intermediates, thereby enhancing the overall activity of UOR. With its excellent electrocatalytic performance, unique electronic states, and coordination structures, the NiCoCr‐LDH/NF electrode showcases great potential for practical applications in the field of energy catalysis. [ABSTRACT FROM AUTHOR]

On page 2988, W. Zhang and W. Zheng explore the recent highlights (since 2010) of applying delicately‐arranged single atoms as the smallest functional material. Functional single atoms have been demonstrated in a range of applications from catalysis to electronic devices, benefiting from state‐of‐the‐art characterization techniques. As in the words of Richard Feynman: “There is plenty of room at the bottom!” [ABSTRACT FROM AUTHOR]