Thermal Shock Synthesis for Loading Sub-2 nm Ru Nanoclusters on Titanium Nitride as a Remarkable Electrocatalyst toward Hydrogen Evolution Reaction.

Heterogeneous catalysts embracing metal entities on suitable supports are profound in catalyzing various chemical reactions, and substantial synthetic endeavors in metal-support interaction modulation are made to enhance catalytic performance. Here, it is reported the loading of sub-2 nm Ru nanocrystals (NCs) on titanium nitride support (HTS-Ru-NCs/TiN) via a special Ru-Ti interaction using the high-temperature shock (HTS) method. Direct dechlorination of the adsorbed RuCl, ultrafast nucleation process, and short coalescence duration at ultrahigh temperatures contribute to the immobilization of Ru NCs on TiN support via producing the Ru-Ti interfacial perimeter.

Strain-modulated Ru-O Covalency in Ru-Sn Oxide Enabling Efficient and Stable Water Oxidation in Acidic Solution.

RuO is one of the benchmark electrocatalysts used as the anode material in proton exchange membrane water electrolyser. However, its long-term stability is compromised due to the participation of lattice oxygen and metal dissolution during oxygen evolution reaction (OER). In this work, weakened covalency of Ru-O bond was tailored by introducing tensile strain to RuO octahedrons in a binary Ru-Sn oxide matrix, prohibiting the participation of lattice oxygen and the dissolution of Ru, thereby significantly improving the long-term stability.

Portable Conductometric Sensing Probe for Real-Time Monitoring Ammonia Profile in Coastal Waters.

An ability to real-time and continuously monitor ammonium/ammonia profiles of coastal waters over a prolonged period in a simple and maintenance-free fashion would enable economic conducting large-scale assessments, providing the needed scientific insights to better control and mitigate the impact of eutrophication on coastal ecosystems. However, this is a challenging task due to the lack of capable sensors. Here, we demonstrate the use of a membrane-based conductometric ammonia sensing probe (CASP) for real-time monitoring of ammonia levels in coastal waters.

Constructing Fe-N Sites through Anion Exchange-mediated Transformation of Fe Coordination Environments in Hierarchical Carbon Support for Efficient Oxygen Reduction.

Metal single atoms (SAs) anchored in carbon support via coordinating with N atoms are efficient active sites to oxygen reduction reaction (ORR). However, rational design of single atom catalysts with highly exposed active sites is challenging and urgently desirable. Herein, an anion exchange strategy is presented to fabricate Fe-N moieties anchored in hierarchical carbon nanoplates composed of hollow carbon spheres (Fe-SA/N-HCS).

Stabilization and Performance Enhancement Strategies for Halide Perovskite Photocatalysts.

Solar-energy-powered photocatalytic fuel production and chemical synthesis are widely recognized as viable technological solutions for a sustainable energy future. However, the requirement of high-performance photocatalysts is a major bottleneck. Halide perovskites, a category of diversified semiconductor materials with suitable energy-band-enabled high-light-utilization efficiencies, exceptionally long charge-carrier-diffusion-length-facilitated charge transport, and readily tailorable compositional, structural, and morphological properties, have emerged as a new class of photocatalysts for efficient hydrogen evolution, CO reduction, and various organic synthesis reactions.

Synergistic Cr O @Ag Heterostructure Enhanced Electrocatalytic CO Reduction to CO.

The electrocatalytic CO RR to produce value-added chemicals and fuels has been recognized as a promising means to reduce the reliance on fossil resources; it is, however, hindered due to the lack of high-performance electrocatalysts. The effectiveness of sculpturing metal/metal oxides (MMO) heterostructures to enhance electrocatalytic performance toward CO RR has been well documented, nonetheless, the precise synergistic mechanism of MMO remains elusive. Herein, an in operando electrochemically synthesized Cr O -Ag heterostructure electrocatalyst (Cr O @Ag) is reported for efficient electrocatalytic reduction of CO to CO.

Operando Converting BiOCl into BiO(CO)Cl for Efficient Electrocatalytic Reduction of Carbon Dioxide to Formate.

Bismuth-based materials (e.g., metallic, oxides and subcarbonate) are emerged as promising electrocatalysts for converting CO to formate.

Hydrogen Spillover-Bridged Volmer/Tafel Processes Enabling Ampere-Level Current Density Alkaline Hydrogen Evolution Reaction under Low Overpotential.

Water-alkaline electrolysis holds a great promise for industry-scale hydrogen production but is hindered by the lack of enabling hydrogen evolution reaction electrocatalysts to operate at ampere-level current densities under low overpotentials. Here, we report the use of hydrogen spillover-bridged water dissociation/hydrogen formation processes occurring at the synergistically hybridized NiS/CrS sites to incapacitate the inhibition effect of high-current-density-induced high hydrogen coverage at the water dissociation site and concurrently promote Volmer/Tafel processes. The mechanistic insights critically important to enable ampere-level current density operation are depicted from the experimental and theoretical studies.

Scalable Spray Drying Production of Amorphous V O -EGO 2D Heterostructured Xerogels for High-Rate and High-Capacity Aqueous Zinc Ion Batteries.

Rechargeable aqueous zinc-ion batteries (ZIBs) are promising in stationary grid energy storage due to their advantages in safety and cost-effectiveness, and the search for competent cathode materials is one core task in the development of ZIBs. Herein, the authors design a 2D heterostructure combining amorphous vanadium pentoxide and electrochemically produced graphene oxide (EGO) using a fast and scalable spray drying technique. The unique 2D heterostructured xerogel is achieved by controlling the concentration of EGO in the precursor solution.

Rational design of metal oxide catalysts for electrocatalytic water splitting.

Electrocatalytic energy conversion between electricity and chemical bonding energy is realized through redox reactions with multiple charge transfer steps at the electrode-electrolyte interface. The surface atomic structure of the electrode materials, if appropriately designed, will provide an energetically affordable pathway with individual reaction intermediates that not only reduce the thermodynamic energy barrier but also allow an acceptably fast kinetic rate of the overall redox reaction. As one of the most abundant and stable forms, oxides of transitional metals demonstrated promising electrocatalytic activities towards multiple important chemical reactions.

Interpolation between W Dopant and Co Vacancy in CoOOH for Enhanced Oxygen Evolution Catalysis.

Electronic structure engineering via integrating two defect structures with opposite modulation effects holds the key to fully unlocking the power of a catalyst. Herein, an interpolation principle is proposed to activate CoOOH via W doping and Co vacancies for the oxygen evolution reaction. Density functional theory suggests opposite roles for the W dopant and the Co vacancy but a synergy between them in tuning the electronic states of the Co site, leading to near-ideal intermediate energetics and dramatically lowered catalytic overpotential.

Real-time on-site monitoring of soil ammonia emissions using membrane permeation-based sensing probe.

An ability to real-time, continuously monitor soil ammonia emission profiles under diverse meteorological conditions with high temporal resolution in a simple and maintenance-free fashion can provide the urgently needed scientific insights to mitigate ammonia emission to the atmosphere and improve agricultural fertilization practice. Here, we report an open-chamber deployment unit embedded a gas-permeable membrane-based conductometric sensing probe (OC-GPMCP) capable of on-site continuously monitoring soil ammonia emission flux ( [Formula: see text] ) -time (t) profiles without the need for ongoing calibration. The developed OC-GPMCPs were deployed to a sugarcane field and a cattle farm under different fertilization/meteorological conditions to exemplify their real-world applicability for monitoring soil ammonia emission from agricultural land and livestock farm, respectively.

Coexisting Single-Atomic Fe and Ni Sites on Hierarchically Ordered Porous Carbon as a Highly Efficient ORR Electrocatalyst.

The development of oxygen reduction reaction (ORR) electrocatalysts based on earth-abundant nonprecious materials is critically important for sustainable large-scale applications of fuel cells and metal-air batteries. Herein, a hetero-single-atom (h-SA) ORR electrocatalyst is presented, which has atomically dispersed Fe and Ni coanchored to a microsized nitrogen-doped graphitic carbon support with unique trimodal-porous structure configured by highly ordered macropores interconnected through mesopores. Extended X-ray absorption fine structure spectra confirm that Fe- and Ni-SAs are affixed to the carbon support via FeN and NiN coordination bonds.

Effects of compositional engineering and surface passivation on the properties of halide perovskites: a theoretical understanding.

Halide perovskite solar cells have demonstrated high power conversion efficiency. Compositional engineering and surface passivation technologies have been drawing great attention to enhance their energy conversion efficiency and moisture resistance. In this study, the density functional theory method was employed to understand the effects of compositional engineering at the A site of perovskites and the 3-butenoic acid-based passivation layer on the structural, electronic and optical properties of halide perovskites.

Phosphorus and Sulfur Co-Doped Cobaltous Oxide Synthesized by an Inorganic-Salt-Assisted Method: Reaction Mechanism and Electrocatalytic Application.

An inorganic-salt-assisted synthesis of non-metallic heteroatom (phosphorus and sulfur) co-doped cobaltous oxide (P/S-CoO) has been reported. Potassium sulphate (K SO ) was used as inorganic source of sulfur (S), while triphenyl phosphine (PPh ) was used as phosphorus (P) source. A stepwise mechanistic investigation into the doping process revealed that the decomposition of PPh triggered the release of both the elemental sulfur and phosphorus because of the reducing reaction environment.

Theoretical Understanding of Electrocatalytic Hydrogen Production Performance by Low-Dimensional Metal-Organic Frameworks on the Basis of Resonant Charge-Transfer Mechanisms.

The exploration of low-cost and efficient electrocatalysts for the hydrogen evolution reaction (HER) is a prerequisite for large-scale hydrogen fuel generation. The understanding of the electronic properties of electrocatalysts plays a key role in this exploration process. In this study, our first-principles results demonstrate that the catalytic performance of the 1D metal-organic frameworks (MOFs) can be significantly influenced by engineering the composite of the metal node.

2D Electrocatalysts for Converting Earth-Abundant Simple Molecules into Value-Added Commodity Chemicals: Recent Progress and Perspectives.

The electrocatalytic conversion of earth-abundant simple molecules into value-added commodity chemicals can transform current chemical production regimes with enormous socioeconomic and environmental benefits. For these applications, 2D electrocatalysts have emerged as a new class of high-performance electrocatalyst with massive forward-looking potential. Recent advances in 2D electrocatalysts are reviewed for emerging applications that utilize naturally existing H O, N , O , Cl (seawater) and CH (natural gas) as reactants for nitrogen reduction (N → NH ), two-electron oxygen reduction (O → H O ), chlorine evolution (Cl → Cl ), and methane partial oxidation (CH → CH OH) reactions to generate NH , H O , Cl , and CH OH.

Preparation of 2 nm tungsten oxide nanowires based on two-phase strategy and their ultra-sensitive NO gas sensing properties.

Ultrafine WO (0 < x < 1) nanowires with aspect ratio greater than 100 were successfully synthesized by two-phase strategy. The crystal structure, morphology evolution and thermal stability of the samples were characterized by X-ray diffractometer (XRD), X-ray photoelectron spectrum (XPS), high resolution transmission electron microscopy (HRTEM), and thermal gravimetric analysis (TGA). The morphology of WO nanowires is closely related to the pH value and oleamine content of the reaction system.

Encapsulation of Plasmid DNA by Nanoscale Metal-Organic Frameworks for Efficient Gene Transportation and Expression.

The intracellular delivery and functionalization of genetic molecules play critical roles in gene-based theranostics. In particular, the delivery of plasmid DNA (pDNA) with safe nonviral vectors for efficient intracellular gene expression has received increasing attention; however, it still has some limitations. A facile one-pot method is employed to encapsulate pDNA into zeolitic imidazole framework-8 (ZIF-8) and ZIF-8-polymer vectors via biomimetic mineralization and coprecipitation.

A Yolk-Shell Structured Silicon Anode with Superior Conductivity and High Tap Density for Full Lithium-Ion Batteries.

The poor cycling stability resulting from the large volume expansion caused by lithiation is a critical issue for Si-based anodes. Herein, we report for the first time of a new yolk-shell structured high tap density composite made of a carbon-coated rigid SiO outer shell to confine multiple Si NPs (yolks) and carbon nanotubes (CNTs) with embedded Fe O nanoparticles (NPs). The high tap density achieved and superior conductivity can be attributed to the efficiently utilised inner void containing multiple Si yolks, Fe O NPs, and CNTs Li storage materials, and the bridged spaces between the inner Si yolks and outer shell through a conductive CNTs "highway".

Thickness Tunable Wedding-Cake-like MoS Flakes for High-Performance Optoelectronics.

Atomically thin transition-metal dichalcogenides (TMDCs) have received substantial interest due to their typical thickness-dependent optical and electronic properties and related applications in optoelectronics. However, the large-scale, thickness-tunable growth of such materials is still challenging. Herein, we report a fast growth of thickness-tunable wedding-cake-like MoS flakes on 6-in.

Epitaxial Growth of Two-Dimensional Metal-Semiconductor Transition-Metal Dichalcogenide Vertical Stacks (VSe/MX) and Their Band Alignments.

Two-dimensional (2D) metal-semiconductor transition-metal dichalcogenide (TMDC) vertical heterostructures play a crucial role in device engineering and contact tuning fields, while their direct integration still challenging. Herein, a robust epitaxial growth method is designed to construct multiple lattice-matched 2D metal-semiconductor TMDC vertical stacks (VSe/MX, M: Mo, W; X: S, Se) by a two-step chemical vapor deposition method. Intriguingly, the metallic VSe preferred to nucleate and extend from the energy-favorable edge site of the semiconducting MX underlayer to form VSe/MX vertical heterostructures.

Ultrathin Nitrogen-Doped Holey Carbon@Graphene Bifunctional Electrocatalyst for Oxygen Reduction and Evolution Reactions in Alkaline and Acidic Media.

Efficient nonprecious-metal oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) electrocatalysts are key for the commercial viability of fuel cells, metal-air batteries, and water-splitting systems. Thus, high-performance ORR and OER electrocatalysts in acidic electrolytes are needed to support high-efficiency proton exchange membrane (PEM)-based systems. Herein, we report a new approach to design and prepare an ultrathin N-doped holey carbon layer (HCL) on a graphene sheet that exhibits outstanding bifunctional ORR/OER activities in both alkaline and acidic media.

Enhanced Thermochemical Water Splitting through Formation of Oxygen Vacancy in La Sr BO (B=Cr, Mn, Fe, Co, and Ni) Perovskites.

Oxygen vacancies in catalyst systems play a crucial role in manipulating pivotal redox properties that are strongly dependent on the composition of the material. Herein, for the first time, experimental evidence of a linear correlation between the extent of oxygen vacancy formation in the La Sr BO (B=Cr, Mn, Fe, Co, and Ni) perovskite series and H generation in two-step thermochemical water splitting is reported, with detailed materials characterization by means of thermogravimetric analysis, XRD, SEM, TEM, and energy-dispersive X-ray spectroscopy. Noteworthy O (718 μmol g ) and H (514 μmol g ) production was achieved by the La Sr CoO perovskite in the thermochemical water-splitting process conducted between 1300 and 900 °C.