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Understanding the correlation between the structural evolution of electrocatalysts and their catalytic activity is both essential and challenging. In this study, we investigate this correlation in the context of the oxygen evolution reaction (OER) by examining the influence of structural disorder during and after dynamic structural evolution on the OER activity of Fe−Ni (oxy)hydroxide catalysts using operando X‐ray absorption spectroscopy, alongside other experiments and theoretical calculations. The Debye–Waller factors obtained from extended X‐ray absorption fine structure analyses reflect the degree of structural disorder and exhibit a robust correlation with the intrinsic OER activities of the electrocatalysts. The enhanced OER activity of in situ‐generated metal (oxy)hydroxides derived from different pre‐catalysts is linked to increased structural disorder, offering a promising approach for designing efficient OER electrocatalysts. This strategy may inspire similar investigations in related electrocatalytic energy‐conversion systems. [ABSTRACT FROM AUTHOR]

Exploring efficient transition-metal-based electrocatalysts for oxygen evolution reaction (OER) is imperative but remain challenging for sustainable energy storage and conversion systems. Foreign species doping is a significant regulation strategy to enhance the intrinsic activity of host matrix. However, the potential relationship of structure-activity caused by guest doping elements is seldom tracked systematically. In this case, both theoretical screening and experimental verification are complementarily employed to investigate the guest doping effects of ten first-row transition metals (Sc~Zn) on bimetallic NiCo layered double hydroxide (NiCo-LDH). As a result, the optimized Fe-doped NiCo-LDH is identified as the most promising candidate toward alkaline electrocatalytic OER, which exhibits the quasi-industrial current density of 1000 mA cm-2 at overpotential of400 mV. Meanwhile, it also shows impressively long-term stability of 500 h at 500 mA cm-2 with a negligible activity loss. Moreover, in situ electrochemical Raman spectroscopy unveils the dynamic structure evolution from pre-catalytic state (Fe-NiCo-LDH) to metal oxyhydroxide (Fe-(NiCo)OOH) during the oxidation reaction, and ab-initio molecular dynamics simulations are further performed to confirm the thermodynamic stability of activated Fe-(NiCo)OOH phase. This work provides a promising platform for exploring the critical role of transition metal guest doping on host matrix in developing industrially required OER electrocatalysts. [ABSTRACT FROM AUTHOR]

Despite lithium‐sulfur (Li‐S) batteries possessing ultrahigh energy density as great promising energy storage devices, the suppressing shuttle effect and improving sulfur redox reaction (SROR) are vital for their practical application. Developing high‐activity electrocatalysts for enhancing the SROR kinetics is a major challenge for the application of Li‐S batteries. Herein, single‐molecule iron phthalocyanine species are anchored on the N and P dual‐doped porous carbon nanosheets (Fe‐NPPC) via axial Fe‐N coordination to optimize the electronic structure of active centers. The Fe‐NPPC can promote the catalytic conversion of polysulfides by modulation of the electronic density in active moieties, endowing the Li‐S battery with a high reversible capacity of 1023 mAh g−1 at 1 C as well as an ultralow capacity decay of 0.035% per cycle over 1500 cycles. Even with a high sulfur loading of 7.1 mg cm−2, the Li‐S battery delivers a high areal capacity of 4.8 mAh cm−2 after 150 cycles at 0.2 C. With further increasing the sulfur loading to 9.2 mg cm−2, an excellent areal capacity of up to 9.3 mAh cm−2 is obtained at 0.1 C. [ABSTRACT FROM AUTHOR]

Accelerating slow water dissociation kinetics is key to boosting the hydrogen evolution reaction (HER) in alkaline media. We report the synthesis of atomically dispersed MoOx species anchored on Rh metallene using a one‐pot solvothermal method. The resulting structures expose the oxide‐metal interfaces to the maximum extent. This leads to a MoOx‐Rh catalyst with ultrahigh alkaline HER activity. We obtained a mass activity of 2.32 A mgRh−1 at an overpotential of 50 mV, which is 11.8 times higher than that of commercial Pt/C and surpasses the previously reported Rh‐based electrocatalysts. First‐principles calculations demonstrate that the interface between MoOx and Rh is the active center for alkaline HER. The MoOx sites preferentially adsorb and dissociate water molecules, and adjacent Rh sites adsorb the generated atomic hydrogen for efficient H2 evolution. Our findings illustrate the potential of atomic interface engineering strategies in electrocatalysis. [ABSTRACT FROM AUTHOR]

Electrochemical carbon dioxide reduction reaction (CO2RR) provides a promising pathway for both decreasing atmospheric CO2 concentration and producing valuable carbon‐based fuels. To explore efficient and cost‐effective catalysts for electrochemical CO2RR is of great importance, but remains challenging. Se‐doped carbon nanosheets (Se‐CNs) with a micro‐, meso‐, and macroporous structure are proposed for electrochemical CO2RR. Such an electrocatalyst combines the advantages of Se optimized active sites, hierarchical pores for facilitating reactant or ion penetration, transport and reaction, and large surface area for more accessible active sites. This Se‐CNs electrocatalyst exhibits over 11‐times enhanced partial current density of CO than the CNs without Se doping and high selectivity (90%) for CO2 electroreduction to CO at a low potential of −0.6 V versus the reversible hydrogen electrode (vs RHE). Density function theoretical calculations reveal that the Se introduction in CNs lowers the free energy barrier of CO2RR and inhibits hydrogen evolution reaction effectively, thus improving the selectivity for CO2 reduction to CO. This work presents a new member of the metal‐free electrocatalyst family, which is easily prepared, low cost, adjustable, and highly efficient for CO2RR. [ABSTRACT FROM AUTHOR]

Given the efficiency, stability and sustainability, the carbon-based materials have become one of promising bifunctional electrocatalysts to the electrochemical water splitting, involving hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). However, there are still many challenges about the design and mechanism study of the carbon-based electrocatalysts. In this paper, we reported B, N co-doping carbon nanosheets which were synthesized via cationic intercalation stripping guar gum carbon aerogels pre-crosslinked by borate, B(OH) 4 -. This facile strategy not only realizes the structure tailoring, but also concurrently improves the doping efficiency and the stability of the hetero atoms. Specifically, the cost-efficient carbon-based bifunctional catalyst (B5/GCS) shows an outstanding HER and OER performance displaying a remarkable activity both in acidic and alkaline media, low onset potentials for both HER (39.12 mV) and OER (1.38 V) in the same electrolyte (0.5 M H 2 SO 4). Notably, when employed as the bifunctional electrocatalysts with a two-electrode electrolyzer for water splitting, the B5/GCS generated a cell voltage of 1.45 V to attain 10 mA cm−2 in 0.5 M H 2 SO 4. Furthermore, a series of experiments combining density functional theory calculations revealed that the observed superb water splitting activity could be attributed to a synergistic effect of N, B co-doping and the formation of fragmented nanosheets with topological defects, which collaboratively promotes the proton adsorption and catalytic kinetics. A advanced carbon-based bifunctional catalyst are designed and fabricated by a facile two-step strategy - borate chemical crosslinking guar gum gel and subsequent cationic intercalation stripping, as water splitting catalyst, the optimal B5/GCS exhibits extraordinary HER and OER performance – on par with the benchmark noble metal catalyst. Image 1 [ABSTRACT FROM AUTHOR]

Efficiency of the electrocatalysts for hydrogen evolution reaction (HER) strongly depends on their extrinsic physical properties and intrinsic electronic structures. Among various modulation strategies, nanoalloying is an efficient route to regulate the intrinsic activities of HER intermediates. Herein, we develop a facile and universal one-step pyrolyzed method to fabricate bimetallic Ru-based nanoalloy catalysts encapsulated by B/N co-doped graphitic nanotubes (RuM@BCN, M=Ir, Pt, Ag, Co, and Fe) for high-performance alkaline HER. BCN nanotube substrates provide sufficient open channels, porous structures and strong anchoring effect to achieve fast kinetics and high stability. The bimetallic nanoalloying strategy greatly promotes the water dissociation and hydrogen adsorption ability of the electrocatalysts via modulation on their intrinsic electronic structures. Therefore, the as-made RuM@BCN demonstrates varied HER behaviors by alloying metals, in which RuIr@BCN exhibits the highest alkaline HER activity with an overpotential of 23.6 mV at the current density of 10 mA cm−2, outperforming commercial Pt/C. [Display omitted] • A general and facile strategy is developed to fabricate bimetallic RuM@BCN nanotubes. • Alloying Ru and Ir atoms induces electronic structure changes and promotes alkaline HER. • BCN nanotubes show great potentials to embed various Ru-based nanoalloy catalysts. • RuIr@BCN demonstrates an overpotential of 23.6 mV at 10 mA cm− 2 for alkaline HER. [ABSTRACT FROM AUTHOR]

[Display omitted] • Self-supported electrocatalysts are prepared via solid-state diffusion. • Effective mass-transfer between carbon-layers and Ni endowing electrocatalyst with ultrahigh activity. • The district confinement of CNTs and heteroatomic doping collaboratively promotes kinetics. To satisfy the practical requirements of electrochemical water splitting, developing a flexible, effective and sustainable approach for scalable production of bifunctional electrocatalyst for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is a tremendous issue to be rationally addressed. Herein, a solid-state diffusion strategy with Ni foam and N-doped carbon layers is applied to prepare multi-interfacial, self-supported and N-doped carbon nanotube (NCNT) encapsulated Ni nanoparticles (NPs) array bifunctional electrocatalyst (NCNT-NP@NF). Prominently, this NCNT-NP@NF is scalable to meet the application requirements and can be used as a binder-free electrode for direct the water splitting. The optimal sample demonstrate outstanding HER/OER performance in 1.0 M KOH, with low overpotential (η 10) at 10 mA cm−2 during HER (96.1 mV) and OER (240 mV) process, which is extremely superior to the most reported metal-based electrocatalysts and even better than commercial IrO 2 (400 mV at 10 mA cm−2 for OER). Strikingly, when these bifunctional electrocatalysts are employed in a dual-electrode electrolyzer for water splitting, the NCNT-NP@NF only needs cell voltage of 1.54 V to drive overall water splitting in 1.0 M KOH, and displays excellent long-term stability (150 h for water splitting). Moreover, experiments combined with density functional theory (DFT) calculations clarify that the remarkable electrochemical activity and stability are mainly attribute to the synergistic effect of the uniform distribution of Ni NPs, heteroatomic doping, as well as district confinement effect of NCNT leading to enhanced electronic multi-interfacial transmission, all these factors co-accelerate electrocatalytic kinetics. Accordingly, this solid-state diffusion method possesses a favorable potential to construct a multi-interfacial and self-supported electrocatalysts in the fields of sustainable supply of clean energies. [ABSTRACT FROM AUTHOR]