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The lithium metal anode has emerged as a promising candidate for future high-energy-density batteries. However, its practical application is hindered by the uncontrollable growth of lithium dendrites. In this study, we developed carbon nanotube (CNT)-decorated ZnO-C microspheres, containing multi-voids, as a lithiophilic host material for a stable lithium metal anode using a one-pot synthesis spray pyrolysis process. These microspheres offer ample space for accommodating lithium metal due to the presence of multi-voids. Additionally, the uniform distribution of ZnO nanocrystals and CNTs facilitates homogeneous lithium nucleation without dendrite formation. To understand the role of ZnO nanocrystals in achieving a stable lithium metal anode, density functional theory (DFT) calculations were employed, which demonstrated superior adsorption energies for lithium atoms as well as favorable electronic properties of the ZnO component. Consequently, the ZnO-C-CNT microspheres exhibit a stable lithium plating/stripping behavior, characterized by high Coulombic efficiency and the maintenance of stable voltage profiles in a symmetric cell configuration. When coupling this anode with the LiNi 0.8 Co 0.1 Mn 0.1 O 2 cathode, the assembled full cell demonstrates excellent cycling stability and high-rate capability, indicating its potential for practical applications. A highly stable lithium metal anode is created using a 3D lithiophilic host material made from CNT-decorated ZnO-C microspheres, produced through a one-step spray pyrolysis process. These 3D macroporous structured materials exhibit uniform distribution of lithiophilic species and possess highly conductive carbon, making them excellent candidates for use as lithium metal anode materials. [Display omitted] [ABSTRACT FROM AUTHOR]

The anionic components have a significant role in regulating the electrochemical properties of mixed transition-metal (MTM)-based materials. However, the relationship between the anionic components and their inherent electrochemical properties in MTM-based materials is still unclear. Herein, we report the anion-dependent supercapacitive and oxygen evolution reaction (OER) properties of in situ grown binary Ni–Co–selenide (Se)/sulfide (S)/phosphide (P) nanosheet arrays (NAs) over nickel foam starting from MOF-derived Ni–Co layered double hydroxide precursors. Among them, the Ni–Co–Se NAs exhibited the best specific capacity (289.6 mA h g–1at 4 mA cm–2). Furthermore, a hybrid device constructed with Ni–Co–Se NAs delivered an excellent energy density (74 W h kg–1at 525 W kg–1) and an ultra-high power density (10 832 W kg–1at 46 W h kg–1) with outstanding durability (∼94%) for 10 000 cycles. Meanwhile, the Ni–Co–Se NAs showed superior electrocatalytic OER outputs with the lowest overpotential (235 mV at 10 mA cm–2) and Tafel slope. In addition, Ni–Co–Se NAs outperformed IrO2as an anode in an anion exchange membrane water electrolyzer at a high current density (>1.0 A cm–2) and exhibited a stable performance up to 48 h with a 99% Faraday efficiency. Theoretical analyses validate that the Se promotes OH adsorption and improves the electrochemical activity of the Ni–Co–Se through a strong electronic redistribution/hybridization with an active metal center due to its valence 4p and inner 3d orbital participations. This study will provide in-depth knowledge of bifunctional activities in MTM-based materials with different anionic substitutions.

Mackinawite (FeS) has sulfur-deficient surfaces and may have played a role in the prebiotic chemistry of the Earth because of its catalytic CO2-to-organic conversion ability, suggesting its suitability for electrochemical carbon dioxide reduction (CO2RR) for environmentally friendly and sustainable technologies. To exploit this catalyst, an atomic understanding of the CO2RR mechanism on sulfur-deficient FeS(001) surfaces is required, which we have explored using dispersion-corrected density functional theory calculations. The adsorption energies of CO2on pristine and S-deficient FeS(001) surfaces are −0.17 and −1.62 eV, respectively, indicating that sulfur deficiency favors CO2activation and reduction. In addition, Bader charge population, density of states, and charge density difference analyses confirmed the activation of CO2molecules via charge transfer (0.89e) from the Fe atoms to the adsorbates. We also found that the electrochemical CO2RR over the studied surfaces favors methane in the potential-limiting *CHO → *CH2O (ΔGdiff= 1.27 eV) and *OHCH2O → *CH2O (ΔGdiff= 0.78 eV) steps for reverse water–gas shift and formate pathways, respectively. Concerning C2species, a high surface concentration of the *CO intermediate on the catalyst was found to be crucial, yielding ethane through a potential-limiting *CH–CH2→ *CH2–CH2step (ΔGdiff= 1.00 eV).

Experimental and first-principles studies were conducted to understand the adsorption mechanism of elemental mercury on FeCl3- and CuCl2-impregnated activated carbons. Activated carbon was impregnated with either FeCl3or CuCl2, and their adsorption of elemental mercury was evaluated using a laboratory-scale fixed-bed system. The fixed-bed tests were carried out by injecting only nitrogen gas to investigate the interaction between mercury and the chemical compound impregnated on the activated carbon. The test temperature was 140 °C to simulate the temperature in a particulate matter control device of full-scale facilities, such as coal-fired power plants and waste incinerators. Based on the results, CuCl2-impregnated activated carbons showed much higher adsorption efficiencies for elemental mercury than both activated carbons and FeCl3-impregnated activated carbons. Density functional theory (DFT) calculations revealed that the mercury adsorbates were adsorbed more strongly on the CuCl2(110) surface than on the FeCl3(001) surface. Electronic property analyses revealed that the CuCl2surface was more efficient as a mercury removal adsorbent because more electrons were shared between Hg- and Cu-influenced Cl bonds than those between Hg- and Fe-influenced Cl bonds, which resulted in the stronger Hg adsorption of the former.