Designing efficient electrocatalysts for hydrogen evolution reaction is significant for renewable and sustainable energy conversion. Here, we report single-atom platinum decorated nanoporous Co 0 . 85 Se (Pt/np-Co 0 . 85 Se) as efficient electrocatalysts for hydrogen evolution. The achieved Pt/np-Co 0 . 85 Se shows high catalytic performance with a near-zero onset overpotential, a low Tafel slope of 35 mV dec −1 , and a high turnover frequency of 3.93 s −1 at −100 mV in neutral media, outperforming commercial Pt/C catalyst and other reported transition-metal-based compounds. Operando X-ray absorption spectroscopy studies combined with density functional theory calculations indicate that single-atom platinum in Pt/np-Co 0 . 85 Se not only can optimize surface states of Co 0 . 85 Se active centers under realistic working conditions, but also can significantly reduce energy barriers of water dissociation and improve adsorption/desorption behavior of hydrogen, which synergistically promote thermodynamics and kinetics. This work opens up further opportunities for local electronic structures tuning of electrocatalysts to effectively manipulate its catalytic properties by an atomic-level engineering strategy.

Terahertz technology promises broad applications, which calls for terahertz electromagnetic interference (EMI) shielding materials to alleviate radiation pollution. 2D transition metal carbides and/or nitrides (MXenes) with metallic conductivity are promising for EMI shielding, but simultaneously realizing light weight, high stability, and foldability in a MXene shielding material to meet the requirements of increasingly popular portable and wearable equipment has remained a great challenge. Herein, an ion-diffusion-induced gelation method is demonstrated to synthesize free-standing, light-weight, foldable, and highly stable MXene foams, in which MXene sheets are cross-linked by multivalent metal ions and graphene oxide to form an oriented porous structure. The method is highly efficient, controllable, and versatile for scalable generation of functional 3D MXene structures with arbitrary shapes and synergistic properties. The distinctive cross-linked porous structure endows the light-weight MXene foam with good foldability, outstanding durability and stability in wet environments, and an excellent terahertz shielding effectiveness of 51 dB at a small thickness of 85 μm. This work not only provides an insight for the on-target design of high-performance terahertz shielding materials but also expands the applications of MXenes in 3D macroscopic form.

The electrochemical nitrogen reduction reaction (NRR) process usually suffers extremely low Faradaic efficiency and ammonia yields due to sluggish NN dissociation. Herein, single‐atomic ruthenium modified Mo2CTX MXene nanosheets as an efficient electrocatalyst for nitrogen fixation at ambient conditions are reported. The catalyst achieves a Faradaic efficiency of 25.77% and ammonia yield rate of 40.57 µg h−1 mg−1 at ‐0.3 V versus the reversible hydrogen electrode in 0.5 m K2SO4 solution. Operando X‐ray absorption spectroscopy studies and density functional theory calculations reveal that single‐atomic Ru anchored on MXene nanosheets act as important electron back‐donation centers for N2 activation, which can not only promote nitrogen adsorption and activation behavior of the catalyst, but also lower the thermodynamic energy barrier of the first hydrogenation step. This work opens up a promising avenue to manipulate catalytic performance of electrocatalysts utilizing an atomic‐level engineering strategy.

Maximizing the catalytic activity of single-atom catalysts is vital for the application of single-atom catalysts in industrial water-alkali electrolyzers, yet the modulation of the catalytic properties of single-atom catalysts remains challenging. Here, we construct strain-tunable sulphur vacancies around single-atom Ru sites for accelerating the alkaline hydrogen evolution reaction of single-atom Ru sites based on a nanoporous MoS2-based Ru single-atom catalyst. By altering the strain of this system, the synergistic effect between sulphur vacancies and Ru sites is amplified, thus changing the catalytic behavior of active sites, namely, the increased reactant density in strained sulphur vacancies and the accelerated hydrogen evolution reaction process on Ru sites. The resulting catalyst delivers an overpotential of 30 mV at a current density of 10 mA cm−2, a Tafel slope of 31 mV dec−1, and a long catalytic lifetime. This work provides an effective strategy to improve the activities of single-atom modified transition metal dichalcogenides catalysts by precise strain engineering.

Designing efficient single-atom catalysts (SACs) for oxygen evolution reaction (OER) is critical for water-splitting. However, the self-reconstruction of isolated active sites during OER not only influences the catalytic activity, but also limits the understanding of structureproperty relationships. Here, we utilize a self-reconstruction strategy to prepare a SAC with isolated iridium anchored on oxyhydroxides, which exhibits high catalytic OER performance with low overpotential and small Tafel slope, superior to the IrO 2. Operando X-ray absorption spectroscopy studies in combination with theory calculations indicate that the isolated iridium sites undergo a deprotonation process to form the multiple active sites during OER, promoting the O-O coupling. The isolated iridium sites are revealed to remain dispersed due to the support effect during OER. This work not only affords the rational design strategy of OER SACs at the atomic scale, but also provides the fundamental insights of the operando OER mechanism for highly active OER SACs.

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Design and synthesis of effective electrocatalysts for hydrogen evolution reaction (HER) in wide pH environments are critical to reduce energy losses in water electrolyzers. Here, by using a self-activation strategy, we construct an atomic nickel (Ni) decorated nanoporous iridium (Ir) catalyst, which can create the reaction-favorable chemical environment and maximize the electrochemical active surface area (ECSA), enabling efficient HER over a wide pH range. By using operando X-ray absorption spectroscopy and theoretical calculations, the atomic Ni sites are identified as the synergistic sites, which not only accelerate the water dissociation under operation conditions but also activate the surface Ir sites thus leading to the efficient H2 generation. This work highlights the significance of atomic-level decorating strategy which can optimize the activity of surface Ir atoms with negligible sacrifice of the ECSA.

Miniaturized energy storage devices (MESDs) provide future solutions for powering dispersive electronics and small devices. Among them, aqueous zinc ion microbatteries (ZIMBs) are a type of promising MESDs because of their high‐capacity Zn anode, safe and green aqueous electrolytes, and good battery performances. Herein, for the first time, a simple and powerful strategy to fabricate flexible ZIMBs based on tailored soft templates is reported, which are patterned by engraving and enables to design the ZIMBs featured with arbitrary shapes and on various substrates. The assembled ZIMBs employing α‐MnS as the cathode materials and guar gum gel as the quasi‐solid‐state electrolyte exhibited very high areal specific capacity of up to 178 μAh cm−2, a notable areal energy density of 322 μWh cm−2 and power density of 710 μW cm−2. Footprint areas of the manufactured ZIMBs as small as 40 mm2 can be achieved. The proposed method based on the engraved soft templates provides a practical route for ZIMB and other MESD designs, which is critical for portable and wearable electronics development.