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Noble metals have broad prospects for catalytic applications yet are restricted to a few packing modes with limited structural flexibility. Here, we achieved geometric structure diversification of noble metals by integrating spatially correlated noble metal single atoms (e.g., Pt, Pd, and Ru) into the lattice of transition metal oxides (TMOs, e.g., Co

Potassium-sulfur batteries hold practical promise for next-generation batteries because of their high theoretical gravimetric energy density and low cost. However, significant impediments are the sluggish K2S oxidation kinetics and a lack of atomic-level understanding of K2S oxidation. Here, for the first time, we report the catalytic oxidation of K2S on a sulfur host with Co single atoms immobilized on nitrogen-doped carbon. On the basis of combined spectroscopic characterizations, electrochemical evaluation, and theoretical computations, we show a synergistic effect of dynamic Co-S and N-K interactions to catalyze K2S oxidation. The resultant potassium-sulfur battery exhibited high capacities of 773 and 535 mAh g-1 under high current densities of 1 and 2 C, respectively. These findings provide atomic-scale insights for the rational design of highly efficient sulfur hosts.

Single-atom catalysts (SACs) hold great promise for highly efficient heterogeneous catalysis, yet the practical applications require the development of high-density active sites with flexible geometric structures. The lack of understanding in the dynamic formation process of single atoms in the host framework has been plaguing the controllable synthesis of next generation SACs. Here using Co-based metal-organic frameworks (MOFs) as a starting substrate, we fully elucidated the formation of high-density Pt single atoms with inter-site interactions in derived Co

This work was financially supported by the Australian Research Council (FL170100154, DP160104866, and DP190103472). Y.H.Z. acknowledges financial support from Zhejiang Provincial Natural Science Foundation of China (LR18B030003), National Natural Science Foundation of China (51701181, 21771161), and the Thousand Talents Program for Distinguished Young Scholars. J.S. was supported by the Chinese CSC Scholarship Program. DFT computations were performed by using services offered from the National Computational Infrastructure (NCI) and Phoenix High Performance Computing, which are supported by the Australian Government and the University of Adelaide. XAS measurements were conducted at the Beijing Synchrotron Radiation Facility (1W1B, BSRF)

The development of highly active and reliable photocatalysts for solar hydrogen (H2) production requires the thorough and in-depth understanding of the atomic-level structure/composition-performanc...

Copper is the only metal catalyst that can perform the electrocatalytic CO

High-performance and low-cost photocatalysts play the key role in achieving the large-scale solar hydrogen production. In this work, we report a liquid-exfoliation approach to prepare NiPS

Owing to dwindling fossil fuels reserves, the development of alternative renewable energy sources is globally important. Photocatalytic hydrogen (H

Although proton exchange membrane (PEM) water electrolyzers offer a promising means for generation of hydrogen fuel from solar and wind energy, in acidic environments the corresponding anodic oxyge...

Summary Achieving high activity and long-term stability is a major challenge in the design of catalysts. In particular, the oxygen evolution reaction (OER) in acidic media, which plays a key role in proton exchange membrane electrolyzers for fast hydrogen fuel generation, seriously suffers from rapid degradation of catalysts as a result of the harsh acidic and oxidative conditions. Here, we report a rational design strategy for the fabrication of a heterostructured OER electrocatalyst (Ru@IrOx) that has unique physicochemical properties and in which a strong charge redistribution exists between a highly strained ruthenium core and a partially oxidized iridium shell across the metal-metal oxide heterojunction. The increased valence of the iridium shell and the decreased valence of the ruthenium core activate a synergistic electronic and structural interaction, which results in the enhanced activity and stability of the catalyst compared with the majority of the state-of-the-art ruthenium- and iridium-based materials.

Metal sulfides electrodeposition in sulfur cathodes mitigates the shuttle effect of polysulfides to achieve high Coulombic efficiency in secondary metal-sulfur batteries. However, fundamental understanding of metal sulfides electrodeposition and kinetics mechanism remains limited. Here using room-temperature sodium-sulfur cells as a model system, we report a Mo5N6 cathode material that enables efficient Na2S electrodeposition to achieve an initial discharge capacity of 512 mAh g−1 at a specific current of 1 675 mA g−1, and a final discharge capacity of 186 mAh g−1 after 10,000 cycles. Combined analyses from synchrotron-based spectroscopic characterizations, electrochemical kinetics measurements and density functional theory computations confirm that the high d-band position results in a low Na2S2 dissociation free energy for Mo5N6. This promotes Na2S electrodeposition, and thereby favours long-term cell cycling performance., Incomplete conversion of sodium polysulfides represents a significant issue in room-temperature sodium-sulfur batteries. Here, the authors propose Mo5N6 as an electrocatalyst for efficient Na2S electrodeposition and improved cell cycling performances.

Owing to dwindling fossil fuels reserves, the development of alternative renewable energy sources is globally important. Photocatalytic hydrogen (H2 ) evolution represents a practical and affordable alternative to convert sunlight into carbon-free H2 fuel. Recently, 2D/2D van der Waals heterostructures (vdWHs) have attracted significant research attention for photocatalysis. Here, for the first time a ReS2 /In2 ZnS4 2D/2D vdWH synthesized via a facile physical mixing is reported. It exhibits a highly promoted photocatalytic H2 -evolution rate of 2515 µmol h-1 g-1 . Importantly, this exceeds that for pristine In2 ZnS4 by about 22.66 times. This, therefore, makes ReS2 /In2 ZnS4 one of the most efficient In2 ZnS4 -based photocatalysts without noble-metal cocatalysts. Advanced characterizations and theoretical computations results show that interlayer electronic interaction within ReS2 /In2 ZnS4 vdWH and atomic-level S active centers along the edges of ReS2 NSs work collaboratively to result in the boosted light-induced H2 evolution. Results will be of immediate benefit in the rational design and preparation of vdWHs for applications in catalysis/(opto)electronics.

Confinement of polysulfides in sulfur cathodes is pivotal for eliminating the "shuttle effect" in metal-sulfur batteries, which represent promising solutions for large-scale and sustainable energy storage. However, mechanistic exploration and in-depth understanding for the confinement of polysulfides remain limited. Consequently, it is a critical challenge to achieve highly stable metal-sulfur batteries. Here, based on a 2D metal-organic framework (2D MOF), a new mechanism to realize effective confinement of polysulfides is proposed. A combination of in situ synchrotron X-ray diffraction, electrochemical measurements, and theoretical computations reveal that the dynamic electron states of the Ni centers in the 2D MOF enable the interaction between polysulfides and the MOF in the discharge/charge process to be tuned, resulting in both strong adsorption and fast conversion kinetics of polysulfides. The resultant room-temperature sodium-sulfur batteries are amongst the most stable reported so far, thus demonstrating that the new mechanism opens a promising avenue for the development of high-performance metal-sulfur batteries.

A dual-doping approach for nitrogen-doped carbon-coated SnO2–SnS/graphene nanosheets (N–C@SnO2–SnS/GN) has been developed, using hydrothermal carbonization of sucrose with SnO2-decorated graphene and ammonium thiocyanate and a subsequent thermal treatment. The resulting hybrid manifests a typical two-dimensional core–shell architecture, with a N-doped carbon coating over the SnS- and SnO2-decorated graphene nanosheets. Used as the anode material in lithium ion batteries (LIBs), N–C@SnO2–SnS/GN delivers a high specific capacity of 1236 mA h g−1 at a current density of 0.1 A g−1 after 110 cycles, which outperforms most state-of-the-art tin-based LIB anodes with core–shell structures.

The establishment of electrocatalysts with bifunctionality for efficient oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in acidic environments is necessary for the development of proton exchange membrane (PEM) water electrolyzers for the production of clean hydrogen fuel. RuIr alloy is considered to be a promising electrocatalyst because of its favorable OER performance and potential for HER. Here, the design of a bifunctional electrocatalyst with greatly boosted water-splitting performance from doping RuIr alloy nanocrystals with transition metals that modify electronic structure and binding strength of reaction intermediates is reported. Significantly, Co-RuIr results in small overpotentials of 235 mV for OER and 14 mV for HER (@ 10 mA cm-2 current density) in 0.1 m HClO4 media. Therefore a cell voltage of just 1.52 V is needed for overall water splitting to produce hydrogen and oxygen. More importantly, for a series of M-RuIr (M = Co, Ni, Fe), the catalytic activity dependence at fundamental level on the chemical/valence states is used to establish a novel composition-activity relationship. This permits new design principles for bifunctional electrocatalysts.

Graphene-directed two-dimensional (2D) nitrogen-doped porous carbon frameworks (GPF) as the hosts for sulfur were constructed via the ionothermal polymerization of 1,4-dicyanobenzene directed by the polyacrylonitrile functionalized graphene nanosheets. As cathodes for lithium–sulfur (Li–S) batteries, the prepared GPF/sulfur nanocomposites exhibited a high capacity up to 962 mA h g⁻¹ after 120 cycles at 2 A g⁻¹. A high reversible capacity of 591 mA h g⁻¹ was still retained even at an extremely large current density of 20 A g⁻¹. Such impressive electrochemical performance of GPF should benefit from the 2D hierarchical porous architecture with an extremely high specific surface area, which could facilitate the efficient entrapment of sulfur and polysulfides and afford rapid charge transfer, fast electronic conduction as well as intimate contact between active materials and the electrolyte during cycling.