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MXenes, a class of two-dimensional (2D) materials, have gathered significant attention as excellent electrode materials for various energy applications owing to their remarkable properties such as superior metallic conductivity, abundant surface functionality, high electrical conductivity, hydrophilicity, abundance of surface active sites, enormous cycle life, and ordered lamellar structure. In this study, we present the heterostructured growth of bimetallic Co-NiSe2 on MXene via a simple hydrothermal method. The resulting hybrid structure of Co-NiSe2 exhibits nanorod-like morphology wrapped around MXene sheets. When evaluated as an electrode material for supercapacitors, the Co-NiSe2/MXene composite demonstrates enhanced feasibility, displaying relatively high specific surface area and electrical conductivity, thus exhibiting excellent electrochemical performance. Specifically, the Co-NiSe2/MXene composite exhibits a high specific capacitance of 1394.8 F·g–1 at a current density of 1 A·g–1. Furthermore, the synergetic hybrid material can deliver a high energy density of 20 Wh·kg–1 at a power density of 684 W·kg–1. Importantly, the Co-NiSe2/MXene material exhibits good rate performance and cycle stability, showcasing its potential for advanced energy storage applications. [ABSTRACT FROM AUTHOR]

The anthropogenic carbon dioxide (CO2) fixation and various engineering strategies are gaining very significant attention because of the expansion of the net‐zero carbon environment in the atmosphere. Herein, we designed a sodium aluminate@γ‐alumina (NaAlO2@γ‐Al2O3) catalyst by a simple and facile precipitation and impregnation tactics. A series of different weight percentage NaAlO2@γ‐Al2O3 materials were successfully synthesized and well characterized by using advanced analytical and spectroscopic techniques such as TGA, XRD, FE‐SEM, TEM/HR‐TEM, FT‐IR, Raman, TPD, and XPS analysis. The NaAlO2@γ‐Al2O3 catalyst was employed as a competent catalyst for the CO2 fixation under atmospheric pressure reaction conditions. The catalytic activity results evidently revealed that the cycloaddition reaction successfully achieved 94% styrene oxide conversion and 93% selectivity, along with an 87% yield of the styrene carbonate at 120 °C for 6 h. Furthermore, we comprehensively examined the effect of different reaction parameters such as the effect of sodium aluminate amount, co‐catalyst amount, temperature, and time for CO2 fixation reaction. Additionally, different terminal and internal epoxides were tested under optimized reaction conditions and achieved moderate to excellent yield of the desired cyclic carbonate products. Interestingly, a plausible reaction mechanism was proposed for the styrene carbonate synthesis using NaAlO2@γ‐Al2O3 catalyst surface with the support of characterization and experimental results. Remarkably, the NaAlO2@γ‐Al2O3 catalyst could be easily recoverable and successfully recyclable up to six consecutive cycles without declining its initial catalytic activity along with stable structural and physicochemical properties. [ABSTRACT FROM AUTHOR]

Utilization of anthropogenic CO2 for the synthesis of valuable heterocyclic compounds is a very significant strategy to alleviate environmental issues. Herein, a hollow CeO2 nanosphere (HNS–CeO2) material made using solvothermal-method-assisted synthesis was employed as an efficient catalyst for the selective benzimidazole synthesis under neat and temperate reaction conditions. We examined the controlled reaction conditions for the design of the HNS–CeO2 material through the study of various reaction parameters. Very interestingly, the HNS–CeO2 material exhibited different surface morphological disparities due to the effect of various reaction parameters that were examined comprehensively using field emission scanning electron microscopy analysis. The HNS–CeO2 material was systematically well characterized using various analytical and spectroscopic techniques. The competent catalyst of HNS–CeO2 showed superior catalytic activity (100% conversion, 96% selectivity, and yield) under mild reaction conditions, and these conditions are successfully identified by studying the effect of various reaction parameters. Remarkably, the inherent properties of the HNS–CeO2 catalyst boosted the synergistic effect with the model reagents of o-phenylenediamine, carbon dioxide, dimethylamine borane (DMAB), and base. Moreover, different functional groups substituted benzimidazole compounds are successfully synthesized in good to excellent yields under optimized reaction conditions. The effective contributions of DMAB, base, Lewis acidic, and Lewis basic sites were successfully revealed by proposing a tentative benzimidazole reaction mechanism. Notably, the examined 15 successive recycles with stable catalytic activity performance demonstrated the stable catalytic activity and structural and physicochemical properties of the HNS–CeO2 catalyst. [ABSTRACT FROM AUTHOR]

Summary: Rational designing of advanced electrocatalysts for oxygen evolution reaction (OER) for energy sustainability is challenging. In this perspective, the fabrication of an efficient ternary hybrid composite electrocatalyst consisting of carbon‐based materials and earth‐abundant metal oxides can be thought as a better choice for large‐scale applications. Hybrid of MoO3 and NiO with carbon material would possibly improve stability and conductivity which can assist in improving OER performance. In this regard, we report the development of MoO3/NiO/activated carbon (MoNiAC) ternary hybrid catalyst by a facile, one‐step solution combustion synthesis (SCS) method. The physiochemical properties of the synthesized catalyst were evaluated by advanced analytical and spectroscopic techniques. The MoNiAC ternary hybrid catalyst exhibited a lower over‐potential (279 mV) (without iR compensation) to attain the current density of 10 mA/cm2, and small Tafel slope of 89 mV/dec was accompanied. The superior activity could be ascribed to the synergism between MoO3, NiO, and AC. Furthermore, the stability graph of the hybrid demonstrated appreciable durability of catalyst for upto 8.33 h. The characterization of after stability catalyst suggested no major disturbance in the morphology as well as element distribution signifying the high durability of the hybrid catalyst in terms of activity as well as morphology. The remarkable features such as appreciable OER activity, promising kinetics, and robustness ameliorated the performance of MoNiAC hybrid as an electrocatalyst for OER. [ABSTRACT FROM AUTHOR]

The involvement of CO2 as a renewable and abundant feedstock toward a carbon balanced future has led to production of several value-added products. The primary focus in the current effort is to assess fixation of CO2 and epoxides into cyclic carbonates by employing state-of-the-art metal complexes as promising catalytic systems. Our attention is restricted to Earth-abundant metals such as aluminum, cobalt, iron, zinc and few transition metals in association with different ligand skeletons used for the structural construction of the respective complexes. This review sequentially categorizes these complexes and provides a panoramic overview of their selective catalytic activities and mechanistic understandings based on experimental and theoretical evidences. [ABSTRACT FROM AUTHOR]

Supercapacitors store electrical energy by ion adsorption at the interface of the electrode‐electrolyte (electric double layer capacitance, EDLC) or through faradaic process involving direct transfer of electrons via oxidation/reduction reactions at one electrode to the other (pseudocapacitance). The present minireview describes the recent developments and progress of carbon‐transition metal oxides (C‐TMO) hybrid materials that show great promise as an efficient electrode towards supercapacitors among various material types. The review describes the synthetic methods and electrode preparation techniques along with the changes in the physical and chemical properties of each component in the hybrid materials. The critical factors in deriving both EDLC and pseudocapacitance storage mechanisms are also identified in the hope of pointing to the successful hybrid design principles. For example, a robust carbon‐metal oxide interaction was identified as most important in facilitating the charge transfer process and activating high energy storage mechanism, and thus methodologies to establish a strong carbon‐metal oxide contact are discussed. Finally, this article concludes with suggestions for the future development of the fabrication of high‐performance C‐TMO hybrid supercapacitor electrodes. [ABSTRACT FROM AUTHOR]

A simple approach is developed for preparing carbon-supported Pt nanoparticles (NPs) that has combined homogeneous deposition (HD) of Pt complex species through a gradual increase of pH realized by in situ hydrolysis of urea and uniform reduction by ethylene glycol (EG) in a polyol process, giving control over the size and dispersion of Pt NPs. The electrocatalysis ability of the Pt catalysts produced by HD-EG is shown by determining the electrochemical surface area and fuel-cell polarization performance.