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Electrochemical CO2 conversion offers a sustainable approach to alleviate the energy crisis but remains a long-standing challenge. Herein, atomically dispersed FeN5 sites anchored on N-doped carbon matrix templated by zeolitic imidazole framework-8 (ZIF-8) are facilely synthesized for efficient catalyzing CO2 reduction. The FeN5 single-atom catalyst (Fe-SA/ZIF) presents the Faradaic efficiency of 98% at −0.7 V vs. RHE and over 95% in a wide potential range from −0.4 to −1.0 V vs. RHE, surpassing most of the reported single-atom catalysts for CO2RR. Further density functional theory (DFT) calculations reveal that the outstanding activity of FeN5 sites mainly originates from the lowered d-band center modulated by the out-of-plane coordinated pyridinic N, which reduces the CO adsorption energy from −1.71 to −1.49 eV compared to FeN4 moieties. Thus, the synergistic effect between FeN4 sites and the coordinated pyridine offers new insight in designing outstanding electrocatalysts for multiple applications.

It is vital to explore sustainable and highly efficient catalysts for the oxygen reduction reaction (ORR) with increasing energy demand. Herein, a cobalt (Co) atom dispersed on an N-doped carbon na...

The preparation of freestanding electrodes with excellent conductivity and mechanical strength plays a vital role in simplifying the electrode fabrication process and reducing the electrode cost. H...

Polyanion-type Na3V2(PO4)3 (NVP) is an overwhelmingly attractive cathode material for sodium-ion batteries (SIBs) because of its high structural stability and fast Na+ mobility. However, its practi...

Metal-doped carbon dots (CDs) exhibited promising application in fluorescence and magnetic resonance (MR) imaging, but developing manganese-doped CDs (Mn-CDs) with long wavelength emission and enhanced MR performance is a challenge. Herein, using a one-step solvothermal method, Mn-CDs with redshifted orange emission and enhanced longitudinal relaxation were synthesized for fluorescence and MR imaging. The results indicated that the prepared Mn-CDs had a uniform size distribution, and the average size was 5 nm. Moreover, Mn-CDs possessed a stronger fluorescence performance than Mn-free CDs, and simultaneously, the emission wavelength can redshift from 542 nm (green emission) to 578 nm (orange emission), owing to the increasing N-doping. Because of the movement limit of Mn

Borohydride magnesium is widely studied as a promising hydrogen storage material due to its high gravimetric and volumetric density (14.9 wt % and 112 g/L, respectively). Different types of catalys...

Background: One of the underlying mechanisms of Parkinson’s disease is the aggregation of α-synuclein proteins, including amyloids and Lewy bodies in the brain. Aim: To study the inhibitory effect of doped carbon nanotubes (CNTs) on amyloid aggregation. Materials & methods: Molecular dynamics tools were utilized to simulate the influence of CNTs doped with phosphorus, nitrogen and bromine and nitrogen on the formation of α-synuclein amyloid. Results: The CNTs exhibited strong interactions with α-synuclein, with phosphorus-doped CNTs having the most substantial interactions. Conclusion: Doped-CNTs, especially phosphorus-doped carbon nanotube could effectively prevent α-synuclein amyloid formation, thus, it could be considered as a potential treatment for Parkinson’s disease. However, further in vitro and clinical investigations are required.

The development of low cost, efficient, and sustainable electrocatalysts for the hydrogen evolution reaction (HER) is critical to the success of the hydrogen economy. Low-cost and high-efficiency N...

Conversion of CO2 into valuable chemicals via electrochemical CO2 reduction reaction (CO2RR) is a promising technology to alleviate the energy crisis and the greenhouse effect. Herein, low-cost woo...

The properties and, hence, the application of materials are dependent on the way their constituent atoms are arranged. Here, we report a facile approach to produce body-centered cubic (bcc) and face-centered cubic (fcc) phases of bimetallic FeCo crystalline nanoparticles embedded into nitrogen-doped carbon nanotubes (NCNTs) with equal loading and almost similar particle size for both crystalline phases by a rational selection of precursors. The two electrocatalysts with similar composition but different crystalline structures of the encapsulated nanoparticles have allowed us, for the first time, to account for the effect of crystal structure on the overall work function of electrocatalysts and the concomitant correlation with the oxygen reduction reaction (ORR). This study unveils that the electrocatalysts with lower work function show lower activation energy to facilitate the ORR. Importantly, the difference between the ORR activation energy on electrocatalysts and their respective work functions are found to be identical (∼0.2 eV). A notable decrease in the ORR activity after acid treatment indicates the significant role of encapsulated FeCo nanoparticles in influencing the oxygen electrochemistry by modulating the material property of overall electrocatalysts.

As a promising cost-effective electrocatalyst for hydrogen evolution reaction (HER), molybdenum disulfide (MoS2) has been drawing more attention. However, the desired performances are restricted by...

The supporting effect of a N-doped carbon film induced superior crystallinity in electrodeposited Ni@Ni(OH)2 core–shell nanoparticles. This improvement resulted in a much higher regeneration rate of catalytic sites (NiOOH), leading to higher oxidation currents of sugars. Also, the overpotential of the maltopentaose (G5) oxidation reaction decreased significantly, probably due to the effect of the electrostatic interaction between NPs and G5.

Combining the high operational security of magnesium-ion batteries (MIBs) and the fast Li intercalation mechanism of lithium-ion batteries (LIBs), Li+/Mg2+ hybrid-ion batteries (LMIBs) have been developed and are regarded as a promising source of stored power for applications. However, pristine MoS2 with an interplanar distance of 0.62 nm only allows Li+ intercalation, leading to limited energy densities and mediocre electrochemical performance. Herein, we designed and prepared a material consisting of hierarchical interlayer-expanded MoS2 nanosheets/hollow N-doped carbon nanofibers (O–MoS2/HN-CNFs) with interplanar expanded O–MoS2 (0.94 nm). HN-CNFs adequately conduct electrons, and the expanded interlayer spacing of O–MoS2 ensures that Mg2+ and Li+ simultaneously intercalate into the host, even at 1000 mA g−1. Additionally, O–MoS2/HN-CNFs can significantly reduce the ion diffusion barrier and increase the number of intercalated active sites. As a result, O–MoS2/HN-CNFs exhibited superior rate capabilities, good cycling performance, and long-term cycling stability, with a reversible capacity of 134.4 mA h g−1 at 1000 mA g−1 after 2000 cycles.

Bendiocarb, a type of carbamate pesticide, plays a crucial role in controlling a wide range of pests. Due to its harmful impact on humans and the environment, the need for inexpensive, portable, efficient and easy-to-use analytical devices has become essential. In this study, an environmentally friendly paper-based analytical device (PAD) with a chemiluminescence (CL) sensing platform was investigated and characterized for the facile, reliable and sensitive detection of the bendiocarb pesticide. It is based on the enhancing effect of SO32- on the CL reaction of sulfur, nitrogen-doped carbon quantum dots (S,N-CQDs)-KMnO4 in acidic media. According to the experiments, S,N-CQDs and SO32- both are oxidized by KMnO4 to generate (S,N-CQDs*) and (SO2*) in their excited states, emitting at 510 nm. This indicates that an energy transfer process is taking place from SO2* to S,N-CQDs, resulting in a remarkably intensified CL emission. Interestingly, another emission was also observed around 660 nm contributing to about 20 to 25% of the total CL emission. This emission is related to the Mn2+* species produced by reducing MnO4-. The established multi-emission CL system was tested for analytical applications. Under optimal experimental conditions, a good linear relationship was observed between the bendiocarb concentration and the CL intensity of the established CL system. The linear detection range was 0.1-10 μg mL-1, with a limit of detection (LOD) of 0.02 μg mL-1. Finally, the method was successfully applied for the measurements of bendiocarb in water and juice samples. The obtained recovery values (97.5-105.5) verified the suitable accuracy of the results.

The development of cost-effective, efficient, and novel catalytic systems is always an important topic for heterogeneous catalysis from academia and industrial points of view. Heteroatom-doped carbon materials have gained more and more attention as effective heterogeneous catalysts to replace metal-based catalysts, because of their excellent physicochemical properties, outstanding structure characteristics, environmental compatibility, low cost, inexhaustible resources, and low energy consumption. Doping of heteroatoms can tailor the properties of carbons for different utilizations of interest. In comparison to pure carbon catalysts, these catalysts demonstrate superior catalytic activity in many organic reactions. This review highlights the most recent progress in synthetic strategies to fabricate metal-free heteroatom-doped carbon catalysts including single and multiple heteroatom-doped carbons and the catalytic applications of these fascinating materials in various organic transformations such as oxidation, hydrogenation, hydrochlorination, dehydrogenation, etc.

The construction of an acid resistant catalyst for synthesis of γ-valerolactone from levulinic acid in aqueous media is an important but highly challenging goal. Herein, an efficient Co@NCNT-800 (after 800 °C pyrolysis) catalyst was constructed by confining Co in N-doped carbon nano-tubes (NCNT) from low cost materials by a facile strategy. Combined with the characterization results and control experiments, the in situ formed Co and Co-Ox, but not Co-Nx, proved to be the main synergistic active sites of the catalyst. It was also found that Co species are completely isolated within the bamboo-like NCNT, which could protect the metal nanoparticles from agglomeration and leaching in the strong acid reaction system. The γ-valerolactone yield of no less than 99.9% can be obtained under a relatively mild condition, and the catalytic performance has not been significantly reduced within five cycles. Therefore, this work may pave a way for the design of robust non-noble catalyst, and has potential for the production of γ-valerolactone from biomass in large-scale industries.

Environment-friendly Fe-based material@N-doped carbon nanoparticles imbedded in polylactic acid (PLA) matrix are prepared and applied in microwave absorption field. In the synthesis process, polydopamine (PDA) in the precursor could rationally regulate the phases of the iron-based particles and carbon contents. It turns out that optimizing the chemical composition plays a vital role in modulating microwave absorption performance. For instance, the maximum reflection loss (RLmax) for Fe@N-doped carbon particles (S-120) reaches −61.6 dB (12.56 GHz, 2.1 mm), and the effective bandwidth is 4.48 GHz (from 13.52 GHz to 18 GHz) with a thickness of only 1.7 mm. The excellent microwave absorption performance could be attributed to perfect impedance matching brought by the synergies of multiple components. Moreover, the microwave absorbers display not only high microwave absorption performance but also environment-friendly characteristics that can avoid leaving stubborn waste after failure. The preparation process of the composite is pollution-free and the PLA in the composite can almost be naturally degraded within one month under simulated marine environment. This work may provide a new perspective on preparing high-efficient functional materials which are also harmless to the environment.

Microwave absorbents with specific morphology and structure have fundamental significance for tuning microwave absorption (MA). Herein, N-doped carbon sphere nanoparticles and hollow capsules were successfully fabricated via oxidative polymerization of dopamine in different mixed solutions, without any template preparation or etching process. Compared to solid particles, the microwave absorbents consisting of N-doped carbon with a hollow structure showed enormously enhanced MA performance, exhibiting a broad effective absorption bandwidth (from 12.7 GHz to 17.9 GHz) and a minimum reflection loss of −27.2 dB with a sample thickness of 2.0 mm. This work paves an attractive way for simple and eco-friendly preparation of advanced light weight microwave absorbents.

Co, N co-doped carbon (CoN@C) with properly engineered heteropores was facilely synthesized using metal carbonate hydroxides as metal precursor and multistage porogen. CoN@C therefore exhibits superior ORR catalytic activity with a half-wave potential of 0.876 V vs. RHE, and the CoN@C-based zinc-air battery can be stably cycled for 100 h.

Heteroatom-doped carbon materials (HDCMs) have been widely studied as some of the most prominent material candidates for use in a wide range of applications, such as batteries, supercapacitors (SCs), and the oxygen reduction reaction (ORR). Over the past few years, various metal-free heteroatom-doped carbon composites have been developed via integrating different heteroatoms into carbon with different nanostructures, from single-atom doping (N, P, B, S, etc.) to multiple heteroatom doping (N/P/S, N/S/B, etc.). For the first time, this review comprehensively analyzes the relevant features of HDCMs used in batteries, SCs, and the ORR, and provides guidance for the design of more efficient materials. By controlling the content and types of heteroatom-containing reagents, not only the physical and chemical properties of the material can be adjusted, but also the specific surface area and pore volume can be increased via controlling the morphology, thereby enhancing the electrochemical performance of the material. Subsequently, this review summarizes the developments and the history of HDCMs, including synthesis methods, the relationship between doping (doping position and content) and performance, reaction mechanisms, and evaluations of systems. In addition, the important role of oxygen doping is raised and discussed, to remind researchers not to ignore the role of oxygen in improving material properties. Finally, future developments and challenges relating to key technologies in this thriving field are also discussed in this report.

Biomass-derived carbonaceous materials have been deemed to be one of the up-and-coming electrode materials for high-performance energy storage systems due to their cost-neutral abundant resources, sustainable nature, easy synthesis methods, and environmentally benign features. In this work, various graphene-like porous carbon networks (GPCs) with three-dimensional (3D) hierarchically ordered "ion highways" have been synthesized by the carbonization/activation of orange-peel wastes for use as an electrode material in high-energy supercapacitors. The porous structures and surface morphologies of the GPCs were rationally fine-tuned as a function of the activation agent ratio. The prepared GPCs offered superior specific surface area in addition to a 3D porous structure with a fine-tuned pore size distribution. The electrochemical behaviors of all the GPCs were evaluated in 6.0 M KOH aqueous electrolyte via a three-electrode electrochemical setup. Owing to their synergistic characteristics, including superior specific surface area (1150 m(2) g(-1)), large pore volume, and fine-tuned 3D porous architecture, GPC-3.0 (synthesized with a KOH : GPC ratio of 3.0, by wt.) exhibited the best capacitive behavior amongst the studied GPCs. The 3D hierarchically ordered architecture acts like well-designed ion highways that boost electron transportation, thereby enhancing electrochemical energy storage. A coin-cell-type symmetrical supercapacitor based on GPC-3.0 was tested in both 1.0 M Na2SO4 (salt-in-water) and 12.0 m NaNO3 (water-in-salt) electrolytes. The supercapacitor cell based on the water-in-salt electrolyte offered a wide operating voltage of 2.3 V. The obtained energy density and power density values were comparable to those of commercial high-performance electrical double-layer capacitors. Such notable findings will shed light on next-generation high-rate electrochemical energy storage systems based on biomass-derived carbonaceous materials.

The emergence of carbon quantum dots (CQDs) opens up new opportunities in different branches of science and technology primarily because of their conducive biocompatibility, tunable bandgaps, and u...

We report an electrocatalyst of Pd nanoparticles (NPs) supported on a carbon sphere nanoarchitecture doped with sulfur (S) and nitrogen (N) atoms (PdSNC), which is designed by exploiting a palladiu...

The stagnant chemistry of oxygen evolution reaction (OER) requires intensive studies on the advanced OER catalysts for highly efficient and ultra-stable hydrogen production via water splitting. Her...

It remains a challenge to develop an efficient and facile method to synthesize nonprecious metal electrocatalysts with controlled structure and desired properties. This study reports a two-step pyr...

Disperse metal atoms can boost the catalytic activities of carbon-based electrocatalysts for various important chemical reactions at the heart of clean energy conversion technologies, such as oxyge...

High phosphorus concentrations mainly result in environmental problems such as agricultural pollution and eutrophication, which have great negative influence on many natural water bodies. In this work, calcium lignosulfonate was employed to produce calcium-doped char at 400 and 800 °C. To compare the phosphorus adsorption behaviors of the two carbon materials, batch adsorption experiments were conducted in a phosphorus microenvironment. The factors including the initial solution pH, phosphorus concentration, and adsorbent amount were considered, and the main characteristics of calcium-doped chars before and after adsorption were assessed. The results revealed that the phosphorus removal processes fitted both the Freundlich and pseudo-second-order-kinetic models. According to the Langmuir model, the maximum adsorption capacities of the two adsorbents obtained at 400 and 800 °C toward phosphorus (50 °C) were 53.22 and 17.77 mg/g adsorbent, respectively. The former was rich in calcium carbonate (CaCO3) and hydroxyl and carboxyl groups, and it mainly served as a precipitant and a chelating agent, while the latter with a high surface area was dominant in P adsorption.

Background: Water soluble nitrogen and phosphorus doped carbon dots (CD) have been synthesized using citric acid, tris(2-aminoethyl)amine and orthophosphoric acid via one step microwave assisted pyrolytic method. Methods: The CD synthesized has been characterized using FTIR, UV-Vis, fluorescence spectroscopy and EDAX coupled with SEM techniques. Results: SEM study has shown the formation of nanosized CD with an average size of ~18 nm. Elemental analysis via EDAX has confirmed successful incorporation of nitrogen (30.8% wt) and phosphorus (5.7% wt) atoms in it. The steady state and 3D fluorescence spectroscopic studies have shown its efficient fluorescence emission with emission maxima in the region of ~450 nm. It has shown efficient “turn off” fluorescence behaviour towards transition metal ions like Fe2+ and Co2+ ions and toxic nitrophenolic compounds like p-nitrophenol and picric acid. Its efficient interaction with BSA has been revealed in terms of fluorescence quenching of BSA by steady state, synchronous and 3D fluorescence spectroscopy. It has shown very good in vitro biocompatibility and enhanced cell adhesion properties towards NIH 3T3 fibroblast cells. Moreover, fluorescence microscopy has shown significant uptake of CD by the tested cell line. Conclusion: Such bio-compatible nitrogen and phosphorous doped CD can be potentially useful to estimate metal ions, p-nitrophenol and picric acid using fluorescence spectroscopy and for fluorescence based bio-imaging.

Pharmaceutical contamination is an emerging environmental concern that threatens global health and impacts every hemisphere of existence. The extensive exploitation and unregulated release of these...

Iron oxides have been widely recognized in the energy storage field, owing to the high theoretical capacitance, low cost, and environmental friendliness. However, the intrinsic poor electrical cond...

Metal–organic complex (MOC) multilayers are, for the first time, conformally constructed on Ni foam (NF) via a three-component sequential layer-by-layer (LbL) self-assembly approach and converted t...

In order to improve the cycling capability and rate performance of carbon anode material for sodium ion battery, an easy, green, and scalable thermal pyrolysis method is exploited to synthesize the nitrogen, phosphorus dual‐doped carbon nanosheets from abundant biomass of peach kernel shell and diammonium hydrogen phosphate. This biomass carbon material demonstrates a super‐thin nanosheet microstructure, and its surface area reaches about 2262 m2 g–1. This carbon nanosheet electrode exhibits a large initial coulombic efficiency of 90%, superior rate capability, and high sodium ion storage capacity. It delivers a high Na+ storage capacity of about 332 mAh g–1 at a current density of 100 mA g–1 after 200 cycles. Even at a high current density of 4 A g–1, a good rate performance of 270 mAh g–1 is also achieved. The ultra‐high pseudocapacitance contribution over 90% is the major reason for the excellent Na+ storage performance of this carbon nanosheet electrode. This nitrogen, phosphorus doped biomass carbon anode material with an excellent storage capacity of sodium ion, makes it an appealing candidate for cheap and high‐performance anode materials for sodium ion batteries.

Carbon-based materials, as the traditional anodes for lithium and sodium ion batteries, have drawn extensive attention due to their low cost, available resources and superior cycling stability. Yet the inferior capacitance and sluggish kinetics of these materials severely restrict their further application in lithium and sodium ion batteries. For addressing the aforementioned issues, tremendous efforts have been made and many approaches are proposed, such as designing nanomaterials with various morphologies, creating numerous porosities, and heteroatoms doping. Among them, doping heteroatoms into the lattice of carbon-based materials is demonstrated to be an effective solution based on the results from the experimental and theoretical studies. This approach can modify several characteristics of carbon-based materials obviously, like expanding interlayer distance, generating numerous active sites, and improving electronic conductivity. Therefore, heteroatom-doped carbon-based materials present fantastic cycling stability, excellent rate performance and high capacities compared with pure carbon-based materials. Herein, we present the research progress of heteroatom-doped carbon-based materials for lithium and sodium ion batteries, including N, S, B, P, I, Br, Cl, and F doping/co-doping. The typical synthesis methods, characterization techniques, and electrochemical behaviors of heteroatom-doped carbon-based materials are summarized and clarified. In addition, the importance of heteroatom doping as well as the synergistic effects of co-doping in carbon-based materials is primary emphasized for lithium and sodium storage.

Nitrogen doped graphene quantum dots (N-GQDs) have attracted much attention because of their superior electronic and optical properties. The preparation of N-GQDs can be usually performed via a top...

Efficient synthesis of large-scale vertically aligned nitrogen-doped carbon nanotube arrays (VA-NCNTs) has always been a challenge. In this study, we proposed a facile way to obtain mass VA-NCNTs b...

Metal-containing nanoparticles (M-NPs) in metal/nitrogen-doped carbon (M-N-C) catalysts have been considered hostile to the acidic oxygen reduction reaction (ORR). The relation between M-NPs and the active sites of metal coordinated with nitrogen (MNx ) is hard to establish in acid medium owing to the poor stability of M-NPs. Herein, we develop a strategy to successfully construct a new FeCo-N-C catalyst containing highly active M-NPs and MN4 composite sites (M/FeCo-SAs-N-C). Enhanced catalytic activity and stability of M/FeCo-SAs-N-C is shown experimentally. Calculations reveal that there is a strong interaction between M-NPs and FeN4 sites, which can favor ORR by activating the O-O bond, thus facilitating a direct 4 e- process. Those findings firstly shed light on the highly active M-NPs and FeN4 composite sites for catalyzing acid oxygen reduction reaction, and the relevant reaction mechanism is suggested.