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Considerable efforts are being made to find cheaper and more efficient alternatives to the currently commercially available catalysts based on precious metals for the Hydrogen Evolution Reaction (HER). In this context, fullerenes have started to gain attention due to their suitable electronic properties and relatively easy functionalization. We found that the covalent functionalization of C60, C70 and Sc3N@IhC80 with diazonium salts endows the fullerene cages with ultra-active charge polarization centers, which are located near the carbon-diazonium bond and improve the efficiency towards the molecular generation of hydrogen. To support our findings, Electrochemical Impedance Spectroscopy (EIS), double layer capacitance (Cdl) and Mott-Schottky approximation were performed. Among all the functionalized fullerenes, DPySc3N@IhC80 exhibited a very low onset potential (-0.025 V vs RHE) value, which is due to the influence of the inner cluster on the extra improvement of the electronic density states of the catalytic sites. For the first time, the covalent assembly of fullerenes and diazonium groups was used as an electron polarization strategy to build superior molecular HER catalytic systems.

Endohedral mono-metallofullerenes are the prototypes to understand the fundamental nature and the unique interactions between the encapsulated metals and the fullerene cages. Herein, we report the crystallographic characterizations of four new U-based mono-metallofullerenes, namely, U@Cs(6)-C82, U@C2(8)-C84, U@Cs(15)-C84, and U@C1(12)-C86, among which the chiral cages C2(8)-C84 and C1(12)-C86 have never been previously reported for either endohedral or empty fullerenes. Symmetrical patterns, such as indacene, sumanene, and phenalene, and charge transfer are found to determine the metal positions inside the fullerene cages. In addition, a new finding concerning the metal positions inside the cages reveals that the encapsulated metal ions are always located on symmetry planes of the fullerene cages, as long as the fullerene cages possess mirror planes. DFT calculations show that the metal-fullerene motif interaction determines the stability of the metal position. In fullerenes containing symmetry planes, the metal prefers to occupy a symmetrical arrangement with respect to the interacting motifs, which share one of their symmetry planes with the fullerene. In all computationally analyzed fullerenes containing at least one symmetry plane, the actinide was found to be located on the mirror plane. This finding provides new insights into the nature of metal-cage interactions and gives new guidelines for structural determinations using crystallographic and theoretical methods.

The fundamental relationship between structure and properties, which is called “structure-property”, plays a vital role in the rational designing of high-performance catalysts for diverse electrocatalytic applications. Low-dimensional (LD) nanomaterials, including 0D, 1D, 2D materials, combined with low-nuclearity metal atoms, ranging from single atoms to subnanometer clusters, are currently emerging as rising star nanoarchitectures for heterogeneous catalysis due to their well-defined active sites and unbeatable metal utilization efficiencies. In this work, a comprehensive experimental and theoretical review is provided on the recent development of single atom and atomic cluster-decorated LD platforms towards some typical clean energy reactions, such as water-splitting, nitrogen fixation, and carbon dioxide reduction reactions. The upmost attractive structural properties, advanced characterization techniques, and theoretical principles of these low-nuclearity electrocatalysts as well as their applications in key electrochemical energy devices are also elegantly discussed.

Currently, copper is the most active monometallic catalyst to generate hydrocarbon and oxygenated products. Nevertheless, the huge kinetic barrier of Cu surfaces for the formation of a C–C bond on the path toward C2+ products has remained unsolved to date. In this work, inspired by the successful growth of 2D borophene on Cu (111) surfaces [Nat. Nanotechnol., 2019, 14 (1), 44], we introduce a high density of one-dimensional copper/borophene interface sites for the C–C coupling reaction by using a framework of density functional theory calculations. Cu alone interacts very weakly with CO, while its synergistic interfacial interactions with boron atoms could significantly boost the CO binding strength, thus facilitating C–C coupling. The Cu–boron interface delivers an ultra-low kinetic energy barrier of only 0.42 eV for the CO dimerization step and a thermodynamic potential limiting step of only 0.61 V for the hydrogenation process toward ethanol production, inhibiting the hydrogen evolution reaction. The improved intrinsic catalytic activity can be ascribed to both the synergistic electronic and structural interactions between metal Cu and non-metal B atoms at the interface. Our work predicts an unprecedented family of low-dimensional nanohybrid catalysts towards the efficient electroreduction of CO to ethanol, thus providing a new class of guiding design principles for the broad experimentalist community.

Among all the 2D-carbon materials, graphyne is currently one of the most interesting carbon allotropes besides graphene. It has potential applications in a wide variety of scientific fields owing to its unique sp–sp2 hybrid network, which endows desirable electronic properties towards energy-related applications. In this review, we summarize the recent progress in graphynes for electronic and energy applications from a theoretical point of view. The intrinsic electronic structure of graphyne and its chemical and mechanical properties are comprehensively described. It is hoped that this review could provide a strong theoretical understanding of graphynes, thus accelerating the design of robust and efficient graphyne-based advanced energy and electronic devices in the future.

The design of sustainable procedures for the preparation of cobalt/carbon-based materials as an anode for hydrogen fuel production through electrocatalytic water splitting has attracted much interest in the last few years. Herein, a novel environmentally friendly approach for the development of stable and active catalysts for the oxygen evolution reaction (OER) is reported. In detail, the methodology aimed at developing a sequence of composites having a low cobalt loading ( MW/US > MW > conventional heating, with the best sample requiring an overpotential of 365 mV to deliver a current density of 10 mA cm_2 and a Tafel slope of 58 mV dec_1.

The synthesis, characterization and incorporation of fullerene derivatives bearing primary, secondary and tertiary nitrogen atoms, which possess different basicities, in perovskite solar cells (PSCs), is reported. In this work, we tested the compounds as conventional electron transporting materials (ETMs) in a single layer with phenyl-C61-butyric acid methyl ester (PC61BM) as control. Additionally, we tested the idea of separating the ETM into two different layers: a thin electron extracting layer (EEL) at the interface with the perovskite, and an electron transporting layer (ETL) to transport the electrons to the Ag electrode. The compounds in this work were also tested as EELs with C60 as ETL on top. Our results show that the new fullerenes perform better as EELs than as ETMs. A maximum power conversion efficiency (PCE) value of 18.88% was obtained for a device where a thin layer (∼3 nm) of BPy-C60 was used as EEL, a higher value than that of the control device (16.70%) with only pure C60. Increasing the layer thicknesses led to dramatically decreased PCE values, clearly proving that the compound is an excellent electron extractor from the perovskite layer but a poor transporter as a bulk material. The improved passivation ability and electron extraction capabilities of the BPy-C60 derivative were demonstrated by steady state and time-resolved photoluminescence (SS-and TRPL) as well as electrochemical impedance spectroscopy (EIS) and X-Ray photoelectron spectroscopy (XPS) measurements; likely attributed to the enhanced basicity of the pyridine groups that contributes to a stronger interaction with the interfacial Pb2+.

Nature-inspired hierarchical architectures have recently drawn enormous interest in the materials science community, being considered as promising materials for the development of high-performance wearable electronic devices. Their highly dynamic interfacial interactions have opened new horizons towards the fabrication of sustainable sensing and energy storage materials with multifunctional properties. Nature-inspired assemblies can exhibit impressive properties including ultrahigh sensitivity, excellent energy density and coulombic efficiency behaviors as well as ultralong cycling stability and durability, which can be finely tuned and enhanced by controlling synergistic interfacial interactions between their individual components. This tutorial review article aims to address recent breakthroughs in the development of advanced Nature-inspired sensing and energy storage materials, with special emphasis on the influence of interfacial interactions over their improved properties.

Atomic catalysts (AC) are gaining extensive research interest as the most active new frontier in heterogeneous catalysis due to their unique electronic structures and maximum atom-utilization efficiencies. Among all the atom catalysts, atomically dispersed heteronuclear dual-atom catalysts (HDACs), which are featured with asymmetric active sites, have recently opened new pathways in the field of advancing atomic catalysis. In this review, the up-to-date investigations on heteronuclear dual-atom catalysts together with the last advances on their theoretical predictions and experimental constructions are summarized. Furthermore, the current experimental synthetic strategies and accessible characterization techniques for these kinds of atomic catalysts, are also discussed. Finally, the crucial challenges in both theoretical and experimental aspects, as well as the future prospects of HDACs for energy-related applications are provided. It is believed that this review will inspire the rational design and synthesis of the new generation of highly effective HDACs.

Fullerene-based low-dimensional (LD) heterostructures have emerged as excellent energy conversion materials. We constructed van der Waals 1T-MoS2/C60 0D-2D heterostructures via a one-pot synthetic approach for catalytic hydrogen generation. The interfacial 1T-MoS2-C60 and C60-C60 interactions as well as their electrocatalytic properties were finely controlled by varying the weight percentages of the fullerenes. 1T-MoS2 platforms provided a novel template for the formation of C60 nanosheets (NSs) within a very narrow fullerene concentration range. The heterostructure domains of 1T-MoS2 and C60 NSs exhibited excellent hydrogen evolution reaction (HER) performances, with one of the lowest onset potentials and ΔGH* values for LD non-precious nanomaterials reported to date.

Recently, green chemistry for the development of sustainable production systems requires tremendous research efforts on the design of catalysts through resource-efficient ways. The improvement of their catalytic performances is a key goal in modern society. Several approaches using environmentally friendly chemicals and materials for less hazardous synthesis and catalysis were analyzed. In this review, we focus on the synthesis of nanomaterials and catalytic applications to reduce the environmental impact, especially, by reducing waste, solvents, precursors, and derivatives. In addition, we highlight the special efforts toward the use of renewable feedstocks and their applications as well as the synthetic routes to develop nanocatalysts using a greener chemistry.

The atomically dispersed metal species on nitrogen-doped graphene nanosheets have exhibited impressive catalytic properties towards oxygen evolution, oxygen reduction and carbon dioxide reactions (OER/ORR/CRR), but poor performances for nitrogen reduction reactions (NRR). The main reason is ascribed to the sluggish kinetics of the first and last proton-coupled electron transfer (ET) on the unitary single-atom site. In this work, an asymmetrical dual-metal dimer catalytic center, which is inspired by the active sites of natural enzymes, such as nitrogenases, that efficiently catalyze the reduction of N2 to NH3 through FeMo cofactors, is theoretically reported. Remarkably, the density functional theory (DFT) calculations showed that the random combination of two non-precious metal atoms such as Fe, Co, Mo, W and Ru to form catalytically active bimetallic sites lead to a remarkable reduction of about two times of the first or last hydrogenation free energy barrier step. The resulting Mo-Ru, Mo-Co, Mo-W, Mo-Fe and Fe-Ru dimers exhibited ultra-low onset potentials of only 0.17, 0.27, 0.28, 0.36 and 0.39 V, respectively. Meanwhile, the HER side reaction can be well suppressed during the NRR. The superior catalytic performance in the bimetallic clusters is mainly attributed to both the electron donation from the asymmetrical metal atoms to the terminal side-on of N2 molecules, which significantly polarizes and weakens the N≡N bond, and to the synergistic effect of the dual-metal dimers that moderates the binding strength of the key intermediates. This work constitutes the first DFT study of the N2 electroreduction processes on dual-metal dimer catalytic sites and, consequently, paves the way towards the rational design of highly efficient hetero-bimetallic NRR electrocatalysts.

The rational design of multifunctional catalysts that use non-noble metals to facilitate the interconversion between H2, O2, and H2O is an intense area of investigation. Bimetallic nanosystems with highly tunable electronic, structural, and catalytic properties that depend on their composition, structure, and size have attracted considerable attention. Herein, we report the synthesis of bimetallic nickel-copper (NiCu) alloy nanoparticles confined in a sp2 carbon framework that exhibits trifunctional catalytic properties toward hydrogen evolution (HER), oxygen reduction (ORR), and oxygen evolution (OER) reactions. The electrocatalytic functions of the NiCu nanoalloys were experimentally and theoretically correlated with the composition-dependent local structural distortion of the bimetallic lattice at the nanoparticle surfaces. Our study demonstrated a downshift of the d-band of the catalysts that adjusts the binding energies of the intermediate catalytic species. XPS analysis revealed that the binding energy for Ni 2p3/2 band of the Ni0.25Cu0.75/C nanoparticles was shifted ∼3 times compared to other bimetallic systems, and this was correlated to the high electrocatalytic activity observed. Interestingly, the bimetallic Ni0.25Cu0.75/C catalyst surpassed the OER performance of RuO2 benchmark catalyst exhibiting a small onset potential of 1.44 V vs RHE and an overpotential of 400 mV at 10 mA·cm-2 as well as the electrochemical long-term stability of commercial RuO2 and Pt catalysts and kept at least 90% of the initial current applied after 20 000 s for the OER/ORR/HER reactions. This study reveals significant insight about the structure-function relationship for non-noble bimetallic nanostructures with multifunctional electrocatalytic properties.

We report unique additive–free bifunctional electrodes, composed of GO and rGO, PANI and PVA on carbon cloths, which were fabricated using an easy and innovative in-situ aniline polymerization stra...

The rational design of high-performance trifunctional catalysts for oxygen reduction and oxygen and hydrogen evolution reactions is of vital importance for the implementation of green energy conversion technologies. Herein, trifunctional electrocatalysts comprising cobalt nanoparticles uniformly embedded in porous carbon networks were fabricated using a spent tea leaves (STL) template via a one-step carbothermal-reduction strategy at different temperatures. STL played a synthetic dual role in constructing nanocatalysts by acting as efficient scavengers to trap cobalt cations via electrostatic interactions and as carbon sources to generate a porous carbon matrix. Full characterization of the as-synthesized materials revealed the crucial effect of temperature on the crystallinity, surface area, number of surface defects and interfacial charge distribution properties. Furthermore, the trifunctional catalytic activity of the nanoparticles can be finely tuned by varying the carbonization temperature. Co@PC-7 displayed a superior trifunctional catalytic activity exhibiting an excellent performance for hydrogen production with an overpotential of 153 mV (vs. RHE) to achieve 10 mA cm−2, and an impressive bifunctional oxygen electrocatalytic activity with an ultralow potential difference between OER and ORR (ΔE = η10 − E1/2) of 0.69 V, which is one of the lowest values reported in the literature for transition metal nanocatalysts. The remarkable performance of Co@PC-7 is mainly ascribed to its unique structural properties, which give rise to highly desirable charge distributions at the metal/carbon electrochemical interfaces to perform efficient trifunctional water splitting electrocatalysis.

Low dimensional electrocatalytic heterostructures have recently attracted significant attention in the catalysis community due to their highly tuneable interfaces and exciting electronic features, opening up new possibilities for effective nanometric control of both the charge carriers and energetic states of several intermediate catalytic species. In-depth understanding of electrocatalytic routes at the interface between two or more low-dimensional nanostructures has triggered the development of heterostructure nanocatalysts with extraordinary properties for water splitting reactions, NRR and CO

The design of alternative earth-abundant van der Waals (vdW) nanoheterostructures for bifunctional oxygen evolution/reduction (OER/ORR) electrocatalysis is of paramount importance to fabricate energy-related devices. Herein, we report a simple metal–organic framework (MOF)-derived synthetic strategy to fabricate low-dimensional (LD) nanohybrids formed by zero-dimensional (0D) ZrO2 nanoparticles (NPs) and heteroatom-doped two-dimensional (2D) carbon nanostructures. The 2D platforms controlled the electronic structures of interfacial Zr atoms, thus producing optimized electron polarization for boron and nitrogen-doped carbon (BCN)/ZrO2 nanohybrids. X-ray photoelectron spectroscopy (XPS) and theoretical studies revealed the key role of the synergistic couple effect of boron (B) and nitrogen (N) in interfacial electronic polarization. The BCN/ZrO2 nanohybrid showed excellent bifunctional electrocatalytic activity, delivering an overpotential (η10) of 301 mV to reach a current density of 10 mA–cm–2 for the OER process and a half-wave potential (E1/2) of 0.85 V vs reversible hydrogen electrode (RHE) for the ORR process, which are comparable to the state-of-the-art LD nanohybrids. Furthermore, BCN/ZrO2 also showed competitive performances for water-splitting and zinc–air battery devices. This work establishes a new route to fabricate highly efficient multifunctional electrocatalysts by tuning the electronic polarization properties of 0D–2D electrochemical interfaces.

A graphitic carbon nitride nanostructure has been successfully functionalized by incorporation of different silver contents and subsequent modification with an α-rich protein, namely hemoglobin. Mechanochemistry has been employed, as an efficient and sustainable procedure, for the incorporation of the protein. A complete characterization analysis has been performed following a multitechnique approach. Particularly, XPS data exhibited considerable differences in the C 1s region for the Hb/xAg@CN, ensuring the successful protein anchorage on the surface of the graphitic carbon nitride-based materials. The as-synthesized nanomaterials delivered impressive performance toward hydrogen evolution reactions with an overpotential of 79 mV at a current density of 10 mA/cm2 for Hb/20Ag@CN nanohybrids, which is comparable with the most efficient HER electrocatalysts reported in the literature. The outstanding HER properties were associated with the unique synergistic interactions, quantitatively measured, between AgNPs, Hb tertiary architecture, and the graphitic carbon nitride networks.

A new isolation protocol was recently reported for highly purified metallic Fullertubes D

Generating clean and sustainable hydrogen from water splitting processes represent a practical alternative to solve the energy crisis. Ultrathin two-dimensional materials exhibit attractive properties as catalysts for hydrogen production owing to their large surface-to-volume ratios and effective chemisorption sites. However, the catalytically inactive surfaces of the transition metal dichalcogenides (TMD) possess merely small areas of active chemical sites on the edge, thus decreasing their possibilities for practical applications. Here, we propose a new class of out-of-plane deformed TMD (cTMD) monolayer to anchor transition metal atoms for the activation of the inert surface. The calculated adsorption energy of metals (e.g., Pt) on curved MoS2 (cMoS2) can be greatly decreased by 72% via adding external compressions, compared to the basal plane. The enlarged diffusion barrier energy indicates that cMoS2 with an enhanced fixation of metals could be a potential candidate as a single atom catalyst (SAC). We made a well-rounded assessment of the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER), which are two key processes in water splitting. The optimized Gibbs free energy of 0.02 for HER and low overpotential of 0.40 V for OER can be achieved when the proper compression and supported metals are selected. Our computational results provide inspiration and guidance towards the experimental design of TMD-based SACs.

Transition metal nitrides (TMNs)-based materials have attracted increasing attention in electrochemical nitrogen reduction reaction (eNRR) because of their unique structures and inherent electronic properties. However, the eNRR mechanism on such nitrogen contained catalysts is still unclear, for example, which part of the catalyst act as the active sites, and how to achieve the optimal efficiency is also challenging. In this work, a comprehensive study was conducted to unravel the reaction mechanisms of N

Natural sources display a high potential for the production of sustainable materials because of their exceptional structural and physical features, nontoxicity, biocompatibility, availability and cost-effectiveness. Nanostructured systems show high surface/volume ratio, and unusual electrical, mechanical, surface and magnetic properties. The preparation of heterogeneous nanocatalysts from natural resources has recently become increasingly attractive for researchers. The present overview discuses extensively and comprehensively the main natural sources used to prepare the new generation of safer and cheaper catalytic nanosystems. We place a significant emphasis on both the different synthetic strategies for the preparation of the Nature-inspired nanocatalyst and the role of the natural materials over the structural and morphological properties of the resulting nanocatalysts. The catalytic applications of nature-inspired materials were finally featured, highlighting the advantages of using nanotechnology and environmental resources as well as their potential towards the production of alternative energies.

Polypyrrole-modified iron oxide nanomaterials have been synthesized employing a one-step hydrothermal protocol. The influence of the reaction temperature has been investigated by performing the synthesis at four different temperatures (Ppy@Fe2O3-120 °C, Ppy@Fe2O3-140 °C, Ppy@Fe2O3-160 °C, and Ppy@Fe2O3-180 °C). Synthesized materials exhibited an unprecedentedly peculiar morphology (star/coral reef-like architectures), induced by the presence of pyrrole in the reaction media. Full characterization of the samples revealed the critical influence of temperature on the crystallinity, textural properties and specially on (C+N)/Fe surface ratios in the materials. As-synthesized nanohybrids were integrated into electrodes to construct supercapacitor devices. A effective tuning of the electrochemical features was achieved by controlling the (C+N)/Fe ratio on the surface, strongly dependent on reaction temperature. The best electrochemical performance was reached by Ppy@Fe2O3-180 °C nanohybrid, which exhibited a re...

A protein-templated titania nanocomposite (PT-TiO2) was successfully synthesized by a water-free mechanochemical approach. A biomass valorization strategy was developed by employing egg white from ...

A carbonaceous material with desirable properties for lithium-ion batteries (LIBs) was successfully obtained using a low cost and eco-environmental approach based on the mechanochemical dry milling of spent coffee grounds (SCG) followed by further carbonization at 800 °C. The spent coffee grounds derived carbon material (C-SCG) was employed as anodic material delivering a specific capacity of 360 mAh g−1 in the second cycle at current density of 0.1 A g−1. Additionally, the C-SCG material exhibited a competitive anode performance with a reversible capacity of 285 mAh g−1 and a remarkable coulombic efficiency nearly to 100% from the 2nd cycle. The resulting LIBs showed remarkable capacities retention over 100 cycles with a decay rate per cycle of 0.23%. This work contributes to the development of eco-environmental batteries using low-cost materials as a promising solution for increasing energy storage demands.

The electrocatalytic properties of some endohedral fullerenes for hydrogen evolution reactions (HER) were recently predicted by DFT calculations. Nonetheless, the experimental catalytic performance under realistic electrochemical environments of these 0D-nanomaterials have not been explored. Here, for the first time, we disclose the HER electrocatalytic behavior of seven M

Platinum (Pt)-based-nanomaterials are currently the most successful catalysts for the oxygen reduction reaction (ORR) in electrochemical energy conversion devices such as fuel cells and metal-air batteries. Nonetheless, Pt catalysts have serious drawbacks, including low abundance in nature, sluggish kinetics, and very high costs, which limit their practical applications. Herein, we report the first rationally designed nonprecious Co-Cu bimetallic metal-organic framework (MOF) using a low-temperature hydrothermal method that outperforms the electrocatalytic activity of Pt/C for ORR in alkaline environments. The MOF catalyst surpassed the ORR performance of Pt/C, exhibiting an onset potential of 1.06 V vs RHE, a half-wave potential of 0.95 V vs RHE, and a higher electrochemical stability (ΔE1/2 = 30 mV) after 1000 ORR cycles in 0.1 M NaOH. Additionally, it outperformed Pt/C in terms of power density and cyclability in zinc-air batteries. This outstanding behavior was attributed to the unique electronic synergy of the Co-Cu bimetallic centers in the MOF network, which was revealed by XPS and PDOS.

Fullerene-based low-dimensional (LD) heterostructures have emerged as excellent energy conversion materials. We constructed van der Waals 1T-MoS

An emerging class of heterostructures with unprecedented (photo)electrocatalytic behavior, involving the combination of fullerenes and low-dimensional (LD) nanohybrids, is currently expanding the field of energy materials. The unique physical and chemical properties of fullerenes have offered new opportunities to tailor both the electronic structures and the catalytic activities of the nanohybrid structures. Here, we comprehensively review the synthetic approaches to prepare fullerene-based hybrids with LD (0D, 1D, and 2D) materials in addition to their resulting structural and catalytic properties. Recent advances in the design of fullerene-based LD nanomaterials for (photo)electrocatalytic applications are emphasized. The fundamental relationship between the electronic structures and the catalytic functions of the heterostructures, including the role of the fullerenes, is addressed to provide an in-depth understanding of these emerging materials at the molecular level.

In recent years, the incorporation of molecular enzymes into nanostructured frameworks to create efficient energy conversion biomaterials has gained increasing interest as a promising strategy owing to both the dynamic behavior of proteins for their electrocatalytic function and the unique properties of the synergistic interactions between proteins and nanosized materials. Herein, we review the impact of proteins on energy conversion fields and the contribution of proteins to the improved activity of the resulting nanocomposites. We address different strategies to fabricate protein-based nanocatalysts as well as current knowledge on the structure–function relationships of enzymes during the catalytic processes. Additionally, a comprehensive review of state-of-the-art bioelectrocatalytic materials for water-splitting reactions such as hydrogen evolution reaction (HER) and oxygen evolution reactions (OER) is afforded. Finally, we briefly envision opportunities to develop a new generation of electrocatalysts towards the electrochemical reduction of N2 to NH3 using theoretical tools to built nature-inspired nitrogen reduction reaction catalysts.

Porous carbon encapsulated non-precious metal nanocatalysts have recently opened the ways towards the development of high-performance water remediation and energy conversion technologies. Herein, we report a facile, scalable and green synthetic methodology to fabricate porous carbon encapsulated transition metal nanocatalysts (M@TP: M = Cu, Ni, Fe and Co) using commercial tissue paper. The morphology, crystalline structure, chemical composition and textural properties of the M@TP nanocatalysts were thoroughly characterized. The catalytic activity of the M@TP nanocatalysts was investigated for the degradation of Congo red (CR) via peroxymonosulfate activation. Co@TP-6 was found to be the most active catalyst allowing 97.68% degradation in 30 min with a higher rate constant of 0.109 min−1. The nanocatalysts also displayed a carbon shell thickness-dependent electrocatalytic hydrogen evolution reaction (HER) activity, most likely due to the shielding effect of the carbon layers over the electron transfer (ET) processes at the metal core/carbon interfaces. Remarkably, the Ni@TP-6 electrocatalyst, with the smaller carbon shell thickness, showed the best electrocatalytic performance. They delivered an ultralow onset potential of −30 mV vs RHE, an overpotential of 105 mV at a current density of 10 mA·cm−2 and an excellent electrochemical stability to keep the 92% of the initial current applied after 25000 s, which is comparable with the HER activity of the state-of-the-art Ni-based catalysts.

Here, we report the synthesis and characterization of crystalline C60 nanomaterials and their applications as bifunctional water splitting catalysts. The shapes of the resulting materials were tuned via a solvent engineering approach to form rhombic-shaped nanosheets and nanotubes with hexagonal close packed-crystal structures. The as-synthesized materials exhibited suitable properties as bifunctional catalysts for HER and ORR reactions surpassing by far the electrocatalytic activity of commercially available amorphous C60. The C60 nanotubes displayed the most efficient catalytic performance with a small onset potential of −0.13 V vs. RHE and ultrahigh electrochemical stability properties towards the generation of molecular hydrogen. Additionally, the rotating-disk electrode measurements revealed that the oxygen reduction mechanism at the nanotube electrochemical surfaces followed an effective four-electron pathway. The improved catalytic activity was attributed to the enhanced local electric fields at the high curvature surfaces.

Control of electron-transfer (ET) processes across electrochemically active biomaterials by tuning the surface properties of platform materials plays a key role in the design of highly efficient bi...

In this work, two different strategies have been employed to explore the potential valorization of biomass waste. A TiO2-based sample was prepared by a dry-milling strategy, involving orange peel valorization toward nanostructured materials. Subsequently, ruthenium deposition was accomplished by a chemical reduction method to obtain different ruthenium loadings on the titania support. The prepared catalysts were characterized using a multitechnique approach in terms of chemical, structural, and morphological properties. Levulinic acid, a typical model molecule associated with lignocellulosic biomass, was subsequently converted into N-heterocycles in a continuous flow reactor. The prepared Ru-TiO2 systems exhibited outstanding catalytic performance in terms of conversion and selectivity in comparison with Ru/P25 and Ru/C catalytic references. Maximum activity (79% conversion, 85% selectivity to 1-ethyl-2-(ethylideneamino)-5-methylpyrrolidin-2-ol) was achieved for the sample containing 3 wt % Ru, homogeneou...

The efficient electronic wiring of silica-encapsulated laccases has been applied for the first time to the bioelectrocatalytic reduction of oxygen. The synthesized silica/laccase composites were evaluated electrochemically and characterized by UV–vis, Fourier transform infrared (FT-IR), dynamic light scattering, and X-ray photoelectron spectroscopy. FT-IR measurements showed that laccase preserved its native-like structure after the biosilicification process. The one-pot biosilicification synthesis facilitated the accommodation of the enzymes in highly effective orientations for the direct electron transfer of the T1 redox centers. Consequently, the biosilicified laccase deposited on Ni electrodes exhibited an efficient bioelectrocatalytic oxygen reduction, with current densities of up to 0.94 mA/cm2.

Mechanochemistry has emerged as one of the most interesting synthetic protocols to produce new materials. Solvent-free methodologies lead to unique chemical processes during synthesis with the consequent formation of nanomaterials with new properties. The development of mechanochemistry as a synthetic method is supported by excellent results in a wide range of applications. This feature highlights some representative contributions focused on protocols that could be easily extended to the synthesis of other advanced nanomaterials. Materials for batteries, supercapacitors, and catalytic processes are discussed, indicating the potential future directions of each field. Theoretical aspects and a revision of recent real in situ analyses of the synthesis procedures are also featured. This contribution attempts to present, in a comprehensive way, mechanochemistry as an open research line and a consolidated methodology to synthesize advanced nanomaterials.

The acid/base interfacial behavior of mixed self-assembled monolayers (SAMs) of 1-decanethiol (DT) and 11-mercaptoundecanoic acid (MUA) formed on gold from a micellar medium has been characterized by electrochemical impedance spectroscopy (EIS) and infrared reflection–absorption spectroscopy (IRRAS) titration experiments as a function of their surface composition. The surface composition is determined from the interfacial capacitance of the SAMs that behave as a dielectric medium of the expected thickness for well-organized layers. The interaction parameter and the apparent and the intrinsic surface pKa values of these pH-responsive SAMs are obtained by fitting the EIS and IR titration curves to the 1-pK model. The shift in the surface pKa while decreasing the MUA surface fraction resembles the behavior of homogeneously mixed systems. The trends observed can be explained by the lowering of intermolecular in-plane repulsive interactions between neighboring MUA molecules and by the local solvation and hydro...