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Conventional sulfur vacancies, characterized by the symmetric coordination of metal cations (M1–SV–M1), typically serve as catalytic sites for CO2 chemisorption. However, symmetric SV sites, with a uniform charge distribution across adjacent metal sites, enable sluggish electron transfer kinetics for CO2 activation and dissociation, as well as a low defect-band center that renders photoexcited electrons less energetic. Herein, we introduced a Cu dopant into SV-rich SnS2 nanosheets (Cu–SnS2–SV) to construct asymmetric Cu–SV–Sn sites, which steer CO2 photoreduction to CO with a production rate of 48.6 μmol g−1 h−1 in the absence of a photosensitizer and scavenger, 18-fold higher than that of SnS2–SV with symmetric Sn–SV–Sn sites. Experimental investigations combined with theoretical simulations reveal that an asymmetric Cu–SV–Sn structure, compared with a symmetric Sn–SV–Sn structure, allows an upshift of the defect-band center, which significantly mitigates the energy loss associated with electron relaxation from the conduction band to the defect band. Moreover, the advantages of the Cu–SV–Sn sites over the Sn–SV–Sn sites are demonstrated not only by the increased Sn–S covalency, which facilitates electron transfer from catalysts to adsorbates, but also by the improved ability to stabilize COOH* intermediates, which lowers the activation energy barrier of the rate-determining step. [ABSTRACT FROM AUTHOR]

The efficient conversion and storage of solar energy for chemical fuel production presents a challenge in sustainable energy technologies. Metal nitrides (MNs) possess unique structures that make them multi‐functional catalysts for water splitting. However, the thermodynamic instability of MNs often results in the formation of surface oxide layers and ambiguous reaction mechanisms. Herein, we present on the photo‐induced reconstruction of a Mo‐rich@Co‐rich bi‐layer on ternary cobalt‐molybdenum nitride (Co3Mo3N) surfaces, resulting in improved effectiveness for solar water splitting. During a photo‐oxidation process, the uniform initial surface oxide layer is reconstructed into an amorphous Co‐rich oxide surface layer and a subsurface Mo−N layer. The Co‐rich outer layer provides active sites for photocatalytic oxygen evolution reaction (POER), while the Mo‐rich sublayer promotes charge transfer and enhances the oxidation resistance of Co3Mo3N. Additionally, the surface reconstruction yields a shortened Co−Mo bond length, weakening the adsorption of hydrogen and resulting in improved performance for both photocatalytic hydrogen evolution reaction (PHER) and POER. This work provides insight into the surface structure‐to‐activity relationships of MNs in solar energy conversion, and is expected to have significant implications for the design of metal nitride‐based catalysts in sustainable energy technologies. [ABSTRACT FROM AUTHOR]

Ti3C2Tx MXene shows great promise as a supercapacitor electrode material owing to its high conductivity and pseudocapacitive nature. Phosphorus doping is an efficient strategy to boost its capacitance due to the synergistic effect of the P–O and P–C species formed. However, the contribution to enhanced capacitance from specific phosphorus doped species in P-doped Ti3C2Tx remains largely unexplored. Herein, phosphorus atoms are selectively grafted onto Ti3C2Tx MXene, introducing only P–O doped species and how this doping configuration contributes to capacitance is unraveled. The results show that 2.1 at% P-doped Ti3C2Tx delivers a capacitance enhancement of 35% (437 F g−1 at 2 mV s−1) in comparison with pristine MXene and outstanding cycling stability. Multiple in situ and ex situ characterization studies along with DFT calculations collectively reveal that the formed P–O bonds are new active sites for a two-proton bonding-debonding process, leading to enhanced charge storage and capacitive performance in MXene. However, higher surface phosphorus doping would destroy crystal integrity of MXene and leads to performance deterioration. [ABSTRACT FROM AUTHOR]

Semicrystalline polymer dielectrics (SPDs) are highly sought‐after state‐of‐the‐art dielectric materials. As the disorder in SPDs degrades their electrical properties, homogeneously ordered SPDs are desired. However, complex crystallization behaviors of polymers make such homogeneity elusive. Polymer lamellar single crystals (PLSCs), the most regularly‐ordered form of SPDs possible under mild crystallizing conditions, are ideal platforms for understanding and developing high‐performance dielectric materials. Here, a typical and widely used SPD, polyethylene (PE) is selected as the model material. We successfully obtained, large, uniform, and high‐quality PE PLSCs and devised a non‐destructive strategy to construct PE PLSC‐based vertical capacitors. These nanometer‐thick capacitors exhibit exceptional dielectric properties, with a high breakdown strength of 6.95 MV/cm and a low dielectric constant of 2.14±0.07, that outperform the properties of any existing neat PE. This work provides novel insights into exploring the performance possibility of ordered SPDs and reveals the PLSCs as potential high‐performance dielectric materials. [ABSTRACT FROM AUTHOR]

Highlights: A simple two-step multi-element co-doping strategy is proposed to fabricate core-shell structured LiCoO2 based on the different diffusivities of dopant ions. The high diffusivity Al3+/Mg2+ ions occupy the core of single-crystal grain while the low diffusivity Ti4+ ions enrich the shell layer. In-situ XRD demonstrates the mitigated structural distortion under a high cut-off voltage of 4.6 V, resulting in a significantly improved cycling stability. Inactive elemental doping is commonly used to improve the structural stability of high-voltage layered transition-metal oxide cathodes. However, the one-step co-doping strategy usually results in small grain size since the low diffusivity ions such as Ti4+ will be concentrated on grain boundaries, which hinders the grain growth. In order to synthesize large single-crystal layered oxide cathodes, considering the different diffusivities of different dopant ions, we propose a simple two-step multi-element co-doping strategy to fabricate core–shell structured LiCoO2 (CS-LCO). In the current work, the high-diffusivity Al3+/Mg2+ ions occupy the core of single-crystal grain while the low diffusivity Ti4+ ions enrich the shell layer. The Ti4+-enriched shell layer (~ 12 nm) with Co/Ti substitution and stronger Ti–O bond gives rise to less oxygen ligand holes. In-situ XRD demonstrates the constrained contraction of c-axis lattice parameter and mitigated structural distortion. Under a high upper cut-off voltage of 4.6 V, the single-crystal CS-LCO maintains a reversible capacity of 159.8 mAh g−1 with a good retention of ~ 89% after 300 cycles, and reaches a high specific capacity of 163.8 mAh g−1 at 5C. The proposed strategy can be extended to other pairs of low- (Zr4+, Ta5+, and W6+, etc.) and high-diffusivity cations (Zn2+, Ni2+, and Fe3+, etc.) for rational design of advanced layered oxide core–shell structured cathodes for lithium-ion batteries. [ABSTRACT FROM AUTHOR]

Ruthenium (Ru), benefitting from efficient water dissociation ability, is considered a good candidate for alkaline hydrogen evolution reaction (HER); however, the strong binding of H intermediates over Ru sites leads to a limited desorption behavior and thus an unsatisfactory HER activity. Here, we propose a strategy to fabricate a well-defined hetero-interface via anchoring Ru nanoparticles on Co4N nanorods grown on nickel foam (Ru/Co4N/NF). The as-prepared Ru/Co4N/NF catalyst is demonstrated to effectively catalyze water splitting into hydrogen in an alkaline electrolyte, with an overpotential of 145 mV to reach 100 mA cm−2 and a Tafel slope of 25 mV dec−1, far surpassing bare Ru/NF and Co4N/NF. Experimental observations combined with computational simulations reveal that the charge migration from Ru to Co4N contributes to the formation of electron-deficient Ru sites and shifts the d-band center away from the Fermi level, which is conducive to hydrogen desorption. Meanwhile, the electron coupling effect between Ru and Co4N reduces the H2O adsorption energy and allows more electrons to participate in H2O molecule activation. [ABSTRACT FROM AUTHOR]

The controlled synthesis of hollow structure transition metal compounds has long been a very interesting and significant research topic in the energy storage and conversion fields. Herein, an ultrasound-assisted chemical etching strategy is proposed for fabricating concave Ni(OH)2 nanocubes. The morphology and composition evolution of the concave Ni(OH)2 nanocubes suggest a possible formation mechanism. The as-synthesized Ni(OH)2 nanostructures used as supercapacitor electrode materials exhibit high specific capacitance (1624 F g−1 at 2 A g−1) and excellent cycling stability (77% retention after 4000 cycles) due to their large specific surface area and open pathway. In addition, the corresponding hybrid capacitor (Ni(OH)2//graphene) demonstrates high energy density (42.9 Wh kg−1 at a power density of 800 W kg−1) and long cycle life (78% retention after 4000 cycles at 5 A g−1). This work offers a simple and economic approach for obtaining concave Ni(OH)2 nanocubes for energy storage and conversion. [ABSTRACT FROM AUTHOR]

A Ni-rich cobalt-free layered cathode material (LiNixMn1−xO2) is promising due to its low cost, excellent structural stability, and thermal stability. However, low Li-ion diffusion kinetics, highly reactive Ni4+, and stress-induced intragranular micro-cracking restrict its further application. Here, we report dual-functional boron-modification (doping and coating) on a cobalt-free single-crystal layered cathode (B-LiNi0.75Mn0.25O2) via a simple solid-state method. The boron atoms prefer to occupy the tetrahedral interstices in the Li layer during the sintering process, which enlarges the c-axis for fast Li-ion diffusion kinetics and can also serve as a pillar to achieve an ultra-low (1.62%) c-axis lattice contraction at 80% state of charge (SOC). And boron doping passivates the lattice O, inhibits the irreversible phase transition and provides excellent thermal stability at a high cut-off voltage of 4.5 V. On the other hand, the byproduct LiBO2 can improve Li-ion diffusion and alleviate side reactions at the electrode/electrolyte interface by serving as a Li-ion conductive coating layer. As a result, B–LiNi0.75Mn0.25O2 is almost free of inter- and intragranular micro-cracking with faster Li-ion diffusion kinetics. It delivers 176.6 mA h g−1 at 1C and achieves 82.9% capacity retention after 200 cycles. This work not only provides a low-cost and scalable method to remove Co from conventional Ni-rich layered cathodes, but also reveals the commercial feasibility of highly safe single-crystal layered cathode materials. [ABSTRACT FROM AUTHOR]

Inevitable dissolution in aqueous electrolytes, intrinsically low electrical conductivity, and sluggish reaction kinetics have significantly hampered the zinc storage performance of vanadium oxide‐based cathode materials. Herein, core–shell N‐doped carbon‐encapsulated amorphous vanadium oxide arrays, prepared via a one‐step nitridation process followed by in situ electrochemical induction, as a highly stable and efficient cathode material for aqueous zinc‐ion batteries (AZIBs) are reported. In this design, the amorphous vanadium oxide core provides unobstructed ions diffusion routes and abundant active sites, while the N‐doped carbon shell can ensure efficient electron transfer and greatly stabilize the vanadium oxide core. The assembled AZIBs exhibit remarkable discharge capacity (0.92 mAh cm−2 at 0.5 mA cm−2), superior rate capability (0.51 mAh cm−2 at 20 mA cm−2), and ultra‐long cycling stability (≈100% capacity retention after 500 cycles at 0.5 mA cm−2 and 97% capacity retention after 10 000 cycles at 20 mA cm−2). The working mechanism is further validated by in situ X‐ray diffraction combined with ex situ tests. Moreover, the fabricated cathode is highly flexible, and the assembled quasi‐solid‐state AZIBs present stable electrochemical performance under large deformations. This work offers insights into the development of high‐performance amorphous vanadium oxide‐based cathodes for AZIBs. [ABSTRACT FROM AUTHOR]

The cycling stability of batteries is closely related to the dynamic evolution of solid electrolyte interphases (SEIs) in response to the discharging/charging processes. Here, the state‐of‐the‐art cryogenic transmission electron microscopy (cryo‐TEM) and spectroscopy are utilized to probe the SEI breathing behavior induced by discharging/charging on the conversion‐type anode made of Fe2O3 quasi‐cubes. The incorporation of the identical‐location strategy allows the tracking of the evolution of the same SEIs at different charge states. SEI breathing is shown to involve swelling (contracting) upon lithiation (de‐lithiation) driven by the reversible compositional change. Bare Fe2O3 anodes develop an unstable SEI layer due to the intermixing with the lithiation product Li2O, which exhibits a large thickness variation upon breathing as well as excessive growth. A transition from organic to inorganic‐type SEI is also identified upon cycling, which gives rise to significantly increased SEI resistance. To tailor the SEI behavior, N‐doped carbon coating is applied on Fe2O3 (Fe2O3@CN), which can effectively separate the lithiation product from SEI. A thinner and chemically more stable SEI layer develops on Fe2O3@CN, resulting in remarkably enhanced cycling stability compared to bare Fe2O3. This work demonstrates the importance of understanding and optimizing the dynamic behavior of SEIs to achieve better battery performance. [ABSTRACT FROM AUTHOR]

The cavitation effect, as a kind of geochemical phenomenon, widely exists under intense hydrodynamic circumstances, turbulent streams, earthquakes, or waterfalls and anywhere else where a shear force abruptly breaks the continuity of liquid surfaces. The development of an efficient and cheap sonocatalyst is hence one of the effective ways to utilize the cavitation effect to harness energy. In this study, we use a flower-like cobalt nitride nanowires catalyst with rich nitrogen-vacancy nanostructures to achieve efficient sonocatalytic hydrogen production in various water resources. In pure water, an exceptional sonocatalytic hydrogen generation rate of 28.5 μmol g–1 h–1 is delivered by the flower-like cobalt nitride nanowires. More interestingly, hydrogen peroxide, a high-value oxidation product, is also detected in the liquid phase after ultrasonic wave vibrations. Due to the acid/alkali resistance and corrosion resistance of the transition metal nitrides (TMNs), cobalt nitride nanowires can also produce hydrogen in acidic water, alkaline water, seawater, and wastewater. Enriched active sites in cobalt nitride nanowires greatly promote the recombination of radicals generated by the implosion of cavitation bubbles, which promotes sonochemical reaction efficiency. In addition, the cobalt nitride nanowire catalyst displays excellent stability and reusability during the sonochemical catalytic reaction. The findings are anticipated to be useful for further research on transition metal nitride materials as prospective sonocatalysts for energy conversion and environmental remediation. [ABSTRACT FROM AUTHOR]

Triboelectric nanogenerators (TENGs) are devices that can harvest energy from mechanical motions; such devices can be used to power wearable sensors and various low-power electronics. To increase the lifetime of the device, scientists mainly use the method of making TENG in a hard skeleton to simplify the complex possible relative movements between two triboelectric parts. However, the hard skeletons cannot be embedded in soft and lightweight clothing. To make matters worse, the materials used in the garments must be able to withstand high mechanical forces when worn, such as the pressure of more than 100 KPa exerted by body pressure or everyday knocks. Notably, the TENGs are usually made of fragile materials, such as vacuum-evaporated metal electrodes and nano-sized coatings, on the contact interface; these electrodes and coatings often chip or wear off under the action of external loads. In this work, we succeeded in creating a thin, light-weight, but extremely robust garment-integrated triboelectric nanogenerator (G-TENG) that can be embedded in clothing and pass the water wash test. First, we chemically deposited a durable electrode with flexible properties for G-TENG using a novel technique called polymer-assisted metal deposition (PAMD). The as-formed metal electrodes are firmly bonded to the plastic substrate by a sub-10 nm adhesive polymer brush and can withstand a pressure of 22.5 MPa and a tear force of 0.7 MPa. We then removed the traditionally used fragile nanoparticle materials and the non-durable poly-dimethylsiloxane (PDMS) layer at the triboelectric interface, and then used a cost-effective, durable and slightly flowable pressure-sensitive adhesive to form a plastic contact interface. Such a soft plastic interface can ensure full contact of the triboelectric materials, which is excellent in complex environments and ultimately improves the power generation efficiency of the devices. The as-formed low-cost energy harvesting device could become an industry standard for future smart clothing. [ABSTRACT FROM AUTHOR]

Nearly theoretical 100% atomic utilization (supposing each atom could serve as independent sites to play a role in catalyz) of single‐atom catalysts (SACs) makes it highly promising for various applications. However, for most SACs, single‐atom sites are trapped in a solid carbon matrix, which makes the inner parts hardly available for reaction. Herein, a hollow N‐doped carbon confined single‐atom Rh (Rh‐SACs/HNCR) is developed via a coordination‐template method. Both aberration‐corrected scanning transmission electron microscopy and energy dispersive X‐ray spectroscopy mapping confirm the uniform distribution of Rh single atoms. Owning to the unique hollow structure and effective carbon confinement, excessive conversion from pyridinic/pyrrolic N to graphic N is hindered. As a proof of concept, Rh‐SACs/HNCR exhibits superior activity, stability, selectivity, and anti‐poisoning capability in formic acid oxidation reaction compared with the counterpart Rh/C, Pd/C, and Pt/C catalysts. This work provides a powerful strategy for synthesizing hollow carbon confined single‐atom catalysts apply in various energy‐related systems. [ABSTRACT FROM AUTHOR]

The greatest challenge that limits the application of pyro-catalytic materials is the lack of highly frequent thermal cycling due to the enormous heat capacity of ambient environment, resulting in low pyro-catalytic efficiency. Here, we introduce localized plasmonic heat sources to rapidly yet efficiently heat up pyro-catalytic material itself without wasting energy to raise the surrounding temperature, triggering a significantly expedited pyro-catalytic reaction and enabling multiple pyro-catalytic cycling per unit time. In our work, plasmonic metal/pyro-catalyst composite is fabricated by in situ grown gold nanoparticles on three-dimensional structured coral-like BaTiO3 nanoparticles, which achieves a high hydrogen production rate of 133.1 ± 4.4 μmol·g−1·h−1 under pulsed laser irradiation. We also use theoretical analysis to study the effect of plasmonic local heating on pyro-catalysis. The synergy between plasmonic local heating and pyro-catalysis will bring new opportunities in pyro-catalysis for pollutant treatment, clean energy production, and biological applications. While pyrocatalysis offers a means to store energy in chemical bonds from temperature changes, most materials show low conversion efficiencies. Here, authors examine Au nanoparticles on BaTiO3 and demonstrate localized plasmonic heat sources to enhance pyrocatalytic H2 evolution. [ABSTRACT FROM AUTHOR]

The superior properties of diamond have made it a versatile platform for many promising applications in a wide range of areas. Thus, various methods, like chemical vapor deposition (CVD), have been developed to fabricate diamond materials with desired properties. However, the CVD-grown diamond that employs conventional detonation nanodiamonds (DNDs) as seeds is not suitable for many demanding applications that require diamond with high crystallinity, stable color centers, highly emissive features, etc. Here, we propose to use our previously developed salt-assisted air-oxidized (SAAO) nanodiamonds (NDs) as CVD seeds to grow high-quality diamond microparticles that contain silicon vacancy (SiV) centers. The resulting SiV centers hosted in diamond microparticles show superior properties, i.e., significantly increased photoluminescence (PL), narrow PL linewidths, and small inhomogeneous distributions, enabling a wide range of practical applications. We further demonstrate ultrasensitive all-optical thermometry measurement by utilizing the fabricated high-quality microparticle sample. [ABSTRACT FROM AUTHOR]

Inkjet‐printed metal electrodes with desirable morphologies and electrical properties are indispensable cornerstones for printable and flexible electronics. However, methods to fabricate metal electrodes nowadays mostly request the sintering of printed metal particles, which not only will easily damage heat‐sensitive plastic substrates, but also is difficult to achieve a smooth, neat, and highly adhesive electrode structure. Herein, a room‐temperature, solution‐processable copper (Cu) electrode is demonstrated to overcome the above issues. The key is to inkjet print a stable xerogel scaffold with high porosity, good uniformity, and smoothness for growing high‐quality Cu via electroless deposition. Xerogel‐based Cu electrodes exhibit a bi‐layer architecture, consisting of an upper thin‐film Cu (with an electrical conductivity of ≈1.2 × 107 S m−1) and a bottom Cu‐polymer interpenetrated network. The electrodes show an excellent uniformity, surface smoothness, high interfacial energy to the plastic substrates (690–970 mJ m−2), and good flexibility. Taking these merits, the electrodes can be patterned onto various plastic substrates and fabricate all‐solution‐processed electronic devices such as organic thin‐film transistors and organic electrochemical transistors with stable electrical performance. [ABSTRACT FROM AUTHOR]

Doping a foreign atom into metal oxides enables the modulations of the electronic and chemical properties of active sites. SnO2 quantum wires (QWs) possessing large surface area with highly exposed active sites have been demonstrated as promising sensing materials in gas sensors but they still suffer from unsatisfactory selectivity and limits of detection (LODs). Herein, we realize the electronic interaction of transition metal atoms (Cr, Mo, and W) and sub-3 nm ultrathin SnO2 QWs using a general one-step solution process at low temperature (180 °C). Density functional theory calculations reveal that such tailored electronic structures reduce energy barriers for adsorption of gas molecules and transportation of electrons, which facilitates oxygen adsorption and activation, and thus accelerates surface reaction kinetics with H2S molecules. Our results indicate that transition metal doping induces more oxygen vacancies (VO) that lead to boosted H2S chemical-sensing performances. Representative W-doped SnO2 QWs (W–SnO2) achieve enhanced low-temperature H2S-sensing properties with a record LOD of down to 0.48 ppb, which surpasses most of the reported metal oxide-based gas sensors. [ABSTRACT FROM AUTHOR]