Ruthenium Nanoclusters and Single Atoms on α-MoC/N-Doped Carbon Achieves Low-Input/Input-Free Hydrogen Evolution via Decoupled/Coupled Hydrazine Oxidation.

The hydrazine oxidation-assisted H2 evolution method promises low-input and input-free hydrogen production. However, developing high-performance catalysts for hydrazine oxidation (HzOR) and hydrogen evolution (HER) is challenging. Here, we introduce a bifunctional electrocatalyst α-MoC/N-C/RuNSA, merging ruthenium (Ru) nanoclusters (NCs) and single atoms (SA) into cubic α-MoC nanoparticles-decorated N-doped carbon (α-MoC/N-C) nanowires, through electrodeposition. The composite showcases exceptional activity for both HzOR and HER, requiring -80 mV and -9 mV respectively to reach 10 mA cm-2. Theoretical and experimental insights confirm the importance of two Ru species for bifunctionality: NCs enhance the conductivity, and its coexistence with SA balances the H ad/desorption for HER and facilitates the initial dehydrogenation during the HzOR. In the overall hydrazine splitting (OHzS) system, α-MoC/N-C/RuNSA excels as both anode and cathode materials, achieving 10 mA cm-2 at just 64 mV. The zinc hydrazine (Zn-Hz) battery assembled with α-MoC/N-C/RuNSA cathode and Zn foil anode can exhibit 97.3 % energy efficiency, as well as temporary separation of hydrogen gas during the discharge process. Therefore, integrating Zn-Hz with OHzS system enables self-powered H2 evolution, even in hydrazine sewage. Overall, the amalgamation of NCs with SA achieves diverse catalytic activities for yielding multifold hydrogen gas through advanced cell-integrated-electrolyzer system.

Unveiling the nature of Pt-induced anti-deactivation of Ru for alkaline hydrogen oxidation reaction.

While Ru owns superior catalytic activity toward hydrogen oxidation reaction and cost advantages, the catalyst deactivation under high anodic potential range severely limits its potential to replace the Pt benchmark catalyst. Unveiling the deactivation mechanism of Ru and correspondingly developing protection strategies remain a great challenge. Herein, we develop atomic Pt-functioned Ru nanoparticles with excellent anti-deactivation feature and meanwhile employ advanced operando characterization tools to probe the underlying roles of Pt in the anti-deactivation. Our studies reveal the introduced Pt single atoms effectively prevent Ru from oxidative passivation and consequently preserve the interfacial water network for the critical H* oxidative release during catalysis. Clearly understanding the deactivation nature of Ru and Pt-induced anti-deactivation under atomic levels could provide valuable insights for rationally designing stable Ru-based catalysts for hydrogen oxidation reaction and beyond.

Al8 Cluster-Based Metal Halide Frameworks: Balancing Singlet-Triplet Excited States to Achieve White Light and Multicolor Luminescence.

Luminescent metal clusters have attracted great interest in current research; however, the design synthesis of Al clusters with color-tunable luminescence remains challenging. Herein, an [Al8 (OH)8 (NA)16 ] (Al8 , HNA = nicotinic acid) molecular cluster with dual luminescence properties of fluorescence and room-temperature phosphorescence (RTP) is synthesized by choosing HNA ligand as phosphor. Its prompt photoluminescence (PL) spectrum exhibits approximately white light emission at room temperature. Considering that halogen atoms can be used to regulate the RTP property by balancing the singlet and triplet excitons, different CdX2 (X- = Cl- , Br- , I- ) are introduced into the reactive system of the Al8 cluster, and three new Al8 cluster-based metal-organic frameworks, {[Al8 Cd3 Cl5 (OH)8 (NA)17 H2 O]·2HNA}n (CdCl2 -Al8 ), {[Al8 Cd4 Br7 (OH)8 (NA)16 CH3 CN]·NA·HNA}n (CdBr2 -Al8 ) and {[Al8 Cd8 I16 (OH)8 (NA)16 ]}n (CdI2 -Al8 ) are successfully obtained. They realize the color tunability from blue to yellow at room temperature. The origination of fluorescence and phosphorescence has also been illustrated by structure-property analysis and theoretical calculation. This work provides new insights into the design of multicolor luminescent metal cluster-based materials and develops advanced photo-functional materials for multicolor display, anti-counterfeiting, and encryption applications.

Nitrogen-doped Fe7S8 as highly efficient electrocatalysts for the hydrogen evolution reaction.

The high unoccupied d band energy of FeS2 basically results in weak orbital coupling with water molecules, consequently leading to sluggish water dissociation kinetics. Herein, we demonstrate that the N-induced doping effect and phase transition engineering (FeS2 to N-Fe7S8) can downshift the unoccupied d orbitals and strengthen the interfacial orbital coupling to boost the water dissociation kinetics. The fabricated N-Fe7S8/carbon cloth (CC) displays superb hydrogen evolution reaction performance with a low overpotential (89 mV at 10 mA cm-2) and small Tafel slope (105 mV dec-1) under alkaline conditions. It is revealed that the electronic structure of Fe is modulated by N doping and phase transition. The downshifted d band energy can strengthen water adsorption and reduce the energy barrier of water dissociation. Our work provides a new strategy to modify metal sulfide electrocatalysts for electrochemical energy conversion.

Amorphization-Induced Cation Exchange in Indium Oxide Nanosheets for CO2-to-Ethanol Conversion.

Cation exchange (CE) in metal oxides under mild conditions remains an imperative yet challenging goal to tailor their composition and enable practical applications. Herein, we first develop an amorphization-induced strategy to achieve room-temperature CE for universally synthesizing single-atom doped In2O3 nanosheets (NSs). Density functional theory (DFT) calculations elucidate that the abundant coordination-unsaturated sites present in a-In2O3 NSs are instrumental in surmounting the energy barriers of CE reactions. Empirically, a-In2O3 NSs as the host materials successfully undergo exchange with unary cations (Cu2+, Co2+, Mn2+, Ni2+), binary cations (Co2+Mn2+, Co2+Ni2+, Mn2+Ni2+), and ternary cations (Co2+Mn2+Ni2+). Impressively, high-loading single-atom doped (over 10 atom %) In2O3 NSs were obtained. Additionally, Cu/a-In2O3 NSs exhibit an excellent ethanol yield (798.7 µmol g-1 h-1) with a high selectivity of 99.5% for the CO2 photoreduction. This work offers a new approach to induce CE reactions in metal oxides under mild conditions and constructs scalable single-atom doped catalysts for critical applications.

Cooperative Ni(Co)-Ru-P Sites Activate Dehydrogenation for Hydrazine Oxidation Assisting Self-powered H2 Production.

Water electrolysis for H2 production is restricted by the sluggish oxygen evolution reaction (OER). Using the thermodynamically more favorable hydrazine oxidation reaction (HzOR) to replace OER has attracted ever-growing attention. Herein, we report a twisted NiCoP nanowire array immobilized with Ru single atoms (Ru1 -NiCoP) as superior bifunctional electrocatalyst toward both HzOR and hydrogen evolution reaction (HER), realizing an ultralow working potential of -60 mV and overpotential of 32 mV for a current density of 10 mA cm-2 , respectively. Inspiringly, two-electrode electrolyzer based on overall hydrazine splitting (OHzS) demonstrates outstanding activity with a record-high current density of 522 mA cm-2 at cell voltage of 0.3 V. DFT calculations elucidate the cooperative Ni(Co)-Ru-P sites in Ru1 -NiCoP optimize H* adsorption, and enhance adsorption of *N2 H2 to significantly lower the energy barrier for hydrazine dehydrogenation. Moreover, a self-powered H2 production system utilizing OHzS device driven by direct hydrazine fuel cell (DHzFC) achieve a satisfactory rate of 24.0 mol h-1 m-2 .

Amorphous Vanadium Oxide Nanosheets with Alterable Polyhedron Configuration for Fast-Charging Lithium-Ion Batteries.

Transition metal oxides with high theoretical capacities are promising anode materials for lithium-ion batteries (LIBs). However, the sluggish reaction kinetics remain a bottleneck for fast-charging applications due to its slow Li+ migration rate. Herein, a strategy is reported of significantly reducing the Li+ diffusion barrier of amorphous vanadium oxide by constructing a specific ratio of the VO local polyhedron configuration in amorphous nanosheets. The optimized amorphous vanadium oxide nanosheets with a ratio ≈1:4 for octahedron sites (Oh ) to pyramidal sites (C4v ) revealed by Raman spectroscopy and X-ray absorption spectroscopy (XAS) demonstrate the highest rate capability (356.7 mA h g-1 at 10.0 A g-1 ) and long-term cycling life (455.6 mA h g-1 at 2.0 A g-1 over 1200 cycles). Density functional theory (DFT)calculations further verify that the local structure (Oh :C4v = 1:4) intrinsically changes the degree of orbital hybridization between V and O atoms and contributes to a higher intensity of electron occupied states near the Fermi level, thus resulting in a low Li+ diffusion barrier for favorable Li+ transport kinetics. Moreover, the amorphous vanadium oxide nanosheets possess a reversible VO vibration mode and volume expansion rate close to 0.3%, as determined through in situ Raman and in situ transmission electron microscopy.

Spatially Guided Assembly of Polyoxometalate Superlattices and Their Derivatives as High-Power Sodium-Ion Battery Anodes.

The use of polyoxometalate clusters (POMs) with multitudinous structures and surface properties as building blocks has sparked the development of cluster-assembled materials with many prospective applications. In comparison to classic molecules and assembly processes, control over the steric interactions and linkage of large POMs to achieve superlattices with multiple levels of organization remains a great challenge. This work presents a universal approach to modulate the spatial coordination behavior and configurations, and achieves a class of cluster superlattice architectures formed by linear alignment and two-dimensional arrangement of POM units. The formation mechanism is explained as a stepwise co-assembly pathway in which POMs can intervene and dictate a typical stripping-restacking combination mode with the lamellar mediator. These cluster superlattices with long-range POMs ordering impart distinct merits to their derivatives by sulfuration, for which we demonstrate the substantially promoted power and cycling life of these POM derivatives applied as sodium-ion battery anodes.

Multi-Scenario Simulation Analysis of Grain Production and Demand in China during the Peak Population Period.

The transformation of dietary structure brought about by economic development in populous countries is expected to trigger an increase in grain demand, which will put enormous pressure on the grain supply in these nations and even globally. We simulated nine demand scenarios for 2020-2050 based on China's dataset for 15 kinds of grains from 1961-2018. The results show that the maximum difference between the predicted grain demand is 323.8 Mt, equal to the total grain consumption of approximately 600 million Chinese people in one year. To capture which demand scenarios will be met when grain productivity gradually improves within reasonable ranges, we present three projections from the production side. In particular, Projection 1 (P1), which maintains productivity at the current level, only fulfills the projected demand for Scenarios 1-LL, 2-LM, 4-ML, and 7-HL and falls short of the maximum value (Scenario 9-HH) by 117 Mt, which requires an additional 250,000 ha of arable land resources to fill the gap. After raising the preset value of grain yield, the productivity of Projection 2 in turn satisfies the demand scenario 5-MM. When both set variables (grain yields and arable area) increase simultaneously, the output of Projection 3 increases by 15.3% over P1. However, it still lags behind the demand of 68 million tons in Scenario 9-HH, thus implying uncertainty in China's vision of meeting the goal of 95% grain self-sufficiency. Rather than pursuing a single outcome, we discuss multiple possibilities for China's future grain balance and emphasize the adjusting and compensating role of grain trade and storage in the whole system. Ultimately, this paper calls for a better understanding of the supply-demand gap therein and its future trends to support national grain security as well as global sustainable food policies.

Reversing the Nucleophilicity of Active Sites in CoP2 Enables Exceptional Hydrogen Evolution Catalysis.

Precisely constructing the local configurations of active sites to achieve on-demand catalytic functions is highly critical yet challenging. Herein, an anion-deficient strategy to precisely capture Ru single atoms on the anion vacancies of CoP2 (Ru-SA/Pv-CoP2 ) is developed. Refined structural characterizations reveal that the Ru single atoms preferably bind to the anion vacancy sites and consequently build a superior catalytic surface with neighboring CoP and CoRu coordination states for the hydrogen evolution reaction (HER) catalysis. The prepared Ru-SA/Pv-CoP2 nanowires exhibit an unprecedented overpotential of 17 mV at 10 mA cm-2geo , and the corresponding mass activity is 52.2 times higher than the benchmark Pt/C catalyst at the overpotential of 50 mV. Theoretical analysis illustrates that the introduced Ru-SAs can reverse electrons state distribution (from nucleophilic P sites to electrophilic Ru sites) and boost the activation of water molecules and hydrogen production. More importantly, such a construction strategy is also applicable for Pt single atom coupling, suggesting its generality in building catalytic sites. The capability to precisely construct active sites offers a powerful platform to manipulate the catalytic performance of HER catalysts and beyond.

Regulating the Interfacial Electronic Coupling of Fe2 N via Orbital Steering for Hydrogen Evolution Catalysis.

The capability of manipulating the interfacial electronic coupling is the key to achieving on-demand functionalities of catalysts. Herein, it is demonstrated that the electronic coupling of Fe2 N can be effectively regulated for hydrogen evolution reaction (HER) catalysis by vacancy-mediated orbital steering. Ex situ refined structural analysis reveals that the electronic and coordination states of Fe2 N can be well manipulated by nitrogen vacancies, which impressively exhibit strong correlation with the catalytic activities. Theoretical studies further indicate that the nitrogen vacancy can uniquely steer the orbital orientation of the active sites to tailor the electronic coupling and thus benefit the surface adsorption capability. This work sheds light on the understanding of the catalytic mechanism in real systems and could contribute to revolutionizing the current catalyst design for HER and beyond.

N-induced lattice contraction generally boosts the hydrogen evolution catalysis of P-rich metal phosphides.

P-rich transition metal phosphides (TMPs) with abundant P sites have been predicted to be more favorable for hydrogen evolution reaction (HER) catalysis. However, the actual activities of P-rich TMPs do not behave as expected, and the underlying essence especially at the atomic level is also ambiguous. Our structural analysis reveals the inferior activity could stem from the reduced overlap of atomic wave functions between metal and P with the increase in P contents, which consequently results in too strong P-H interaction. To this end, we used N-induced lattice contraction to generally boost the HER catalysis of P-rich TMPs including CoP2, FeP2, NiP2, and MoP2. Refined structural characterization and theoretical analysis indicate the N-P strong interaction could increase the atomic wave function overlap and eventually modulate the H adsorption strength. The concept of lattice engineering offers a new vision for tuning the catalytic activities of P-rich TMPs and beyond.

Tuning orbital orientation endows molybdenum disulfide with exceptional alkaline hydrogen evolution capability.

Molybdenum disulfide is naturally inert for alkaline hydrogen evolution catalysis, due to its unfavorable water adsorption and dissociation feature originated from the unsuitable orbital orientation. Herein, we successfully endow molybdenum disulfide with exceptional alkaline hydrogen evolution capability by carbon-induced orbital modulation. The prepared carbon doped molybdenum disulfide displays an unprecedented overpotential of 45 mV at 10 mA cm-2, which is substantially lower than 228 mV of the molybdenum disulfide and also represents the best alkaline hydrogen evolution catalytic activity among the ever-reported molybdenum disulfide catalysts. Fine structural analysis indicates the electronic and coordination structures of molybdenum disulfide have been significantly changed with carbon incorporation. Moreover, theoretical calculation further reveals carbon doping could create empty 2p orbitals perpendicular to the basal plane, enabling energetically favorable water adsorption and dissociation. The concept of orbital modulation could offer a unique approach for the rational design of hydrogen evolution catalysts and beyond.

Boosting Water Dissociation Kinetics on Pt-Ni Nanowires by N-Induced Orbital Tuning.

Although it is commonly believed that the water-dissociation-related Volmer process is the rate-limiting step for alkaline hydrogen evolution reaction (HER) on Pt-based catalysts, the underlying essence, particularly on the atomic scale, still remains unclear. Herein, it is revealed that the sluggish water-dissociation behavior probably stems from unfavorable orbital orientation and the kinetic issue is successfully resolved via N-induced orbital tuning. Impressively, N modified Pt-Ni nanowires deliver an ultralow overpotential of 13 mV at 10 mA cm-2 , which represents a new benchmark for alkaline HER catalysis. Fine-structural characterization and density functional theory analysis illustrate that the introduced nitrogen can uniquely modulate the electron densities around the Ni sites, and further create empty dz 2 orbitals with superior orientation for water adsorption and activation. More importantly, it is demonstrated that N-induced orbital modulation can generally boost the alkaline HER activities of Pt-Co, Pt-Ni, and Pt-Cu, offering a new perspective for the design of HER catalysts and beyond.

Electron density modulation of NiCo2S4 nanowires by nitrogen incorporation for highly efficient hydrogen evolution catalysis.

Metal sulfides for hydrogen evolution catalysis typically suffer from unfavorable hydrogen desorption properties due to the strong interaction between the adsorbed H and the intensely electronegative sulfur. Here, we demonstrate a general strategy to improve the hydrogen evolution catalysis of metal sulfides by modulating the surface electron densities. The N modulated NiCo2S4 nanowire arrays exhibit an overpotential of 41 mV at 10 mA cm-2 and a Tafel slope of 37 mV dec-1, which are very close to the performance of the benchmark Pt/C in alkaline condition. X-ray photoelectron spectroscopy, synchrotron-based X-ray absorption spectroscopy, and density functional theory studies consistently confirm the surface electron densities of NiCo2S4 have been effectively manipulated by N doping. The capability to modulate the electron densities of the catalytic sites could provide valuable insights for the rational design of highly efficient catalysts for hydrogen evolution and beyond.

Tailoring the d-Band Centers Enables Co4 N Nanosheets To Be Highly Active for Hydrogen Evolution Catalysis.

Endowing materials with specific functions that are not readily available is always of great importance, but extremely challenging. Co4 N, with its beneficial metallic characteristics, has been proved to be highly active for the oxidation of water, while it is notoriously poor for catalyzing the hydrogen evolution reaction (HER), because of its unfavorable d-band energy level. Herein, we successfully endow Co4 N with prominent HER catalytic capability by tailoring the positions of the d-band center through transition-metal doping. The V-doped Co4 N nanosheets display an overpotential of 37 mV at 10 mA cm-2 , which is substantially better than Co4 N and even close to the benchmark Pt/C catalysts. XANES, UPS, and DFT calculations consistently reveal the enhanced performance is attributed to the downshift of the d-band center, which helps facilitate the H desorption. This concept could provide valuable insights into the design of other catalysts for HER and beyond.

Survey data on household electricity consumption and living status in Northwestern China.

Based on 1128 survey questionnaires, main information on urban and rural household electricity consumption was obtained. Original data included household income, the price of electricity, all kinds of electrical appliances, purchase price of main appliances, household size, electricity consumption, as well as power, daily use time of electrical appliances in this data article. These data fully reflected behavior, preferences and living pattern of sample households in electricity use and provided the basis for analyzing the relationship between household electricity consumption and the quality of life ("Does electricity consumption improve residential living status in less developed regions? An empirical analysis using the quantile regression approach" [1]).