Nitrogen-rich Mesoporous Carbon Research Articles

Realizing the label-free sensitive detection of carcinoembryogenic antigen (CEA) in blood serum via a MNC-decorated flexible immunosensor.

A label-free electrochemical immunosensor utilising nitrogen-rich mesoporous carbon (MNC) as the substrate material was developed for the sensitive quantification of carcinoembryonic antigen (CEA). The synergic interactions between MNC and AbCEA also eliminated the need for coupling agents such as EDC/NHS. The novel immunosensor demonstrated a wide detection range from 500 fM (9.04 pg mL-1) to 50 nM (1 μg mL-1) and a low detection limit (LOD) of 500 fM. Moreover, the immunosensor showed sensitivities of 12.27 mA nM-1 cm-2 and 0.066 mA nM-1 cm-2 for detecting CEA in the linear ranges 10 pM to 1 nM and 2 nM to 50 nM, respectively, while maintaining long-term storage stability of 6 weeks. Analysis of real serum sample analysis yielded highly accurate results with recovery rates ranging from 99.3% to 103.7%. Furthermore, the developed paper-based screen-printed electrode exhibited a similar detection range, suggesting its potential for use in point-of-care detection devices in future applications.

Enhanced electrocatalytic activity of 2D ordered mesoporous nitrogen-rich carbon nanosheets functional NiFe2O4 nanospheres for ultrasensitive detection of chlorogenic acid in natural samples

Two-dimensional (2D) porous carbon nanosheets loaded with bimetallic oxide nanospheres are expected to be very attractive electrocatalysts. In this work, we constructed ordered mesoporous nitrogen-rich carbon on the surface of ultrathin-reduced graphene oxide (rGO) using the self-assembly of block polymers and compared the effect of pore structure on the sensing performance. The rGO wrapped by N-doped ordered porous carbon possesses a large specific surface area of 784.9 m2/g. The composite with NiFe2O4 nanospheres with rough surfaces effectively prevented the interlayer accumulation of mNPC@rGO. Meanwhile, the multivalent form of metal elements in NiFe2O4 facilitates the redox reaction. These distinct advantages combine to create an active surface that strongly binds to chlorogenic acid molecules (CGA). Importantly, we have computationally analyzed the reaction mechanism of mNPC@rGO/NiFe2O4 electrocatalytic CGA molecules by density functional theory. In the best case, the mNPC@rGO/NiFe2O4/GCE sensor has a limit of detection (LOD) as low as 2 × 10−11 M and a wide linear range (1 × 10−10−2 × 10−5 M). The sensor displays a remarkable level of selective response to CGA in the presence of other co-interfering species. Furthermore, it has superb repeatability and reproducibility for CGA. The sensor has shown outstanding recovery (95.9%−104.9%) in the practical viability of detecting CGA in food, natural products, and biological samples. This work not only provides a new candidate for the accurate detection of CGA, but also provides insight into the exploration of advanced sensing materials.

Two-dimensional mesoporous nitrogen-rich carbon nanosheets loaded with CeO2 nanoclusters as nanozymes for the electrochemical detection of superoxide anions in HepG2 cells

Two-dimensional (2D) porous carbon-based composite nanosheets loaded with metal oxide nanoclusters are expected to be promising electrocatalysts for high-performance electrochemical sensors. However, for this complicated composite material, strict reaction conditions and complex synthesis steps limit its general application in electrochemical detection. Here we present a facile method to fabricate 2D mesoporous nitrogen-rich carbon nanosheets loaded with CeO2 nanoclusters (2D-mNC@CeO2), for fabricating superoxide anions (O2•−) electrochemical sensor. The method is based on block copolymers self-assembly and the affinity of polydopamine to metal ions to obtain organic-inorganic hybrid, which can be directly converted into 2D-mNC@CeO2 through carbonization strategy without structural deterioration. Characterizations demonstrate that the 2D-mNC@CeO2 owned the 2D N-doped carbon structure with an interlinked hierarchical mesoporous and the uniformly dispersed CeO2 nanoclusters on the surface. Benefitted from the unique structure, the 2D-mNC@CeO2 shortens electron transfer distance, enhances mass transfer efficiency, exposes numerous active sites, and obtain a high Ce3+/Ce4+ ratio for improving electrocatalytic performance. The 2D-mNC@CeO2/SPCEs sensors for O2•− detection has a detection limit of 0.179 μM (S/N = 3) and sensitivity of 401.4 μA cm-2 mM-1. The sensors can be applied to capture electrochemical signals of O2•− released from HepG2 cells, demonstrating the application potential of the sensors to monitor O2•− in biological fields.

Cur-loaded magnetic ZnFe2O4@L-cysteine – Ox, N-rich mesoporous -gC3N4 nanocarriers as a targeted sonodynamic chemotherapeutic agent for enhanced tumor eradication

L-cysteine (L-Cys)-encapsulated ZnFe2O4 nanoparticles (NPs) (ZnFe2O4@L-cysteine) were prepared and then combined with Ox, N-rich mpg-C3N4 nanosheets (ZnFe2O4@L-cysteine- Ox, N-rich mpg-C3N4) (Ox, N-rich mpg-C3N4 as known oxygen-containing functional groups and nitrogen-rich mesoporous graphite-phase carbon nitride). The product was used for targeted delivery of pharmaceutical species and combined therapy. The resulting nanocarrier materials were characterized by HR-TEM, FE-SEM, EDS analysis and element mapping images, FT-IR spectroscopy, XRD, VSM, MTT assay, zeta potential and BET surface area meaurements were performed. The synergistic effect of zinc ferrite (ZnFe2O4) and Ox, N -rich mpg-C3N4 semiconductor was makes the resuting material a candidate for use as a nanosonosensitizer (NSS) for chemosonodynamic therapy (CSDT) and the loading of Curcumin (Cur), which is used to treat lung human cancer cells (A549). The fabricated ZnFe2O4@L-cysteine– Ox, N -rich mp-g-C3N4 nanocarriers exhibited ultrasound (US), as well as, in vitro pH- dependent release of Cur. Upon incubation of with cancer cells in thepresence of the material, O2, O2−., OH., HO2. (reactive oxygen species (ROS)) were efficiently generated upon irradiation with US waves. The application of ZnFe2O4@L-cysteine– Ox, N -rich mpg-C3N4 nanocarriers, as a tool for enhancing the efficacy of ROS through tumor microenvironment is a key strategy for treating some cancers. The developed biodegradable compound was intended to act as a smart drug delivery nanocarriers, with pH and ultrasound trigger and to play a semi-enzymatic sonocatalytic function. The use of deeply penetrating ultrasound waves as the excitation trigger allows the developed nanocarrier to leave hybrid chemotheraputic and SDT effects on the tumors, further to its drug-release function in a pH of 5.5 (rather than in 7.4), which makes it further suitable for delivery of canccer drugs to cells.

Synergistically enhanced iron and zinc bimetallic sites as an advanced ORR electrocatalyst for flow liquid rechargeable Zn–air batteries

A nitrogen-rich mesoporous multi-walled carbon nanotube-dispersed Fe and Zn site oxygen reduction electrocatalyst was designed and fabricated by a secondary coordination chemistry strategy and molten-salt route.

Facile access to template-shape-replicated nitrogen-rich mesoporous carbon nanospheres for highly efficient CO2 capture and contaminant removal

Novel nitrogen-rich mesoporous carbon nanospheres (NMCN) with high surface area and ordered pore geometry are prepared via a facile pathway for efficient CO2 capture and contaminant removal applications.

Copper loaded nitrogen-rich mesoporous carbon nitride as a highly efficient photocatalyst for selective oxidative cleavage of C(sp3)–C(sp3) bonds at room temperature under visible light

A newly designed copper loaded nitrogen-rich mesoporous carbon nitride for photocatalytic selective oxidative cleavage of C(sp3)–C(sp3) bonds at room temperature is presented.

Magnetic composite of \u03b3-Fe2O3 hollow sphere and palladium doped nitrogen-rich mesoporous carbon as a recoverable catalyst for C\u2013C coupling reactions

In this article, palladated-magnetic nitrogen doped porous carbon was prepared from nano magnetic γ-Fe2O3 hollow sphere (h-Fe2O3) with high specific surface area and pore volume. To the purpose, initially h-Fe2O3 was prepared and covered with glucose via hydrothermal treatment with subsequent polymerization of organic shell. The polymerization of melamine-resorcinol–formaldehyde (MRF) was achieved in the presence of Cl-functionalized glucose coated h-Fe2O3 (h-Fe2O3@glu-MRF). Next, the prepared magnetic core–shell hollow sphere was palladated followed by carbonization to yield Pd@h-Fe2O3@C introducing more pores in its structure. The resulted compound, Pd@h-Fe2O3@C, was fully characterized, showing that carbonization process expressively increased the specific surface area. The resulted Pd@h-Fe2O3@C was successfully used for promoting C–C coupling reactions under mild reaction conditions as a heterogeneous catalyst and its activity was compared with some prepared control catalysts. This novel catalyst was magnetically separated simply by a magnet bar and recycled and reused at least in five consecutive runs, without considerable loss of its activity. It is note mentioning that, high recyclability with low Pd leaching are another gains of this protocol.

Vapor deposition of aluminium oxide into N-rich mesoporous carbon framework as a reversible sulfur host for lithium-sulfur battery cathode

Restraining the shuttle effects of lithium polysulfides is the key to improve the cycling reversibility and stability of lithium-sulfur (Li-S) batteries for which design of robust sulfur hosts has been regarded as the most effective strategy. In this work, we report a new type of hybrid sulfur host which is composed of Al2O3 homogenously decorated in nitrogen-rich mesoporous carbon framework (NMC-Al2O3). The NMC-Al2O3 hybrid host features a poly-dispersed spherical morphology and a mesoporous configuration with high surface area and large pore volume that can accommodate a high sulfur content up to 73.5 wt.%. As a result, the fabricated NMC-Al2O3-S cathode exhibits all-round improvements in electrochemical properties in term of capacities (1,212 mAh·g−1 at 0.2 C; 755 mAh·g−1 at 2 C), cycling charge-discharge reversibility (sustainably 100% efficiencies) and stability (1,000 cycles with only 0.023% capacity decay per cycle at 0.5 C). By contrast, the Al2O3-free NMC-S cathode shows both decreased capacities and rapidly descending Coulombic efficiencies during cycling. Density functional theory (DFT) calculations further reveal that the implanted Al2O3 can greatly enhance the chemical adsorption and catalytic conversion for various lithium polysulfides and thereby effectively prevent the polysulfide shuttling and significantly improve the utilizability, reversibility and stability of sulfur cathode.

Insights into mesoporous nitrogen-rich carbon induced synergy for the selective synthesis of ethanol

This work provides an in-depth study on selective ethanol synthesis over cobalt and copper supported on mesoporous nitrogen-rich carbon (MCN) materials. A series of nano-sized Cu–Co@MCN catalysts with variable compositions were designed to maximize the ethanol yield from bio-derived syngas (CO/H2 > 2) by utilizing a nitrogen-rich mesoporous carbon (MCN), which serves two purposes i) the stabilisation of relatively small sized Co nanoparticle crystallites (Co: below 10 nm, geometrical structural promoter) with strong metal support interactions and ii) the promotion of sufficient electronic interactions (electronic promoter) to improve the reducibility of the catalyst. Characterisation of these novel catalysts by a range of techniques (XRD, BET, TPR, HRTEM, XPS, and EXAFS) confirmed that the metal ions are confined within the MCN matrix with highly uniform dispersion. This enhances metal support interactions, which promotes associative CO adsorption over complete CO dissociation. The Cu–Co@MCN catalyst shows potential for higher alcohol synthesis with high product selectivity for C1–C3 oxygenates in the liquid product stream, making it an attractive solution to alternative synthesis of higher alcohols. To elucidate the actual role of surface support nitrogen in-situ synchrotron PXRD studies were performed on the catalyst systems as well as on traditional support alternatives, e.g., carbon nanotubes and activated carbon. Furthermore, insights on catalyst deactivation and selectivity were achieved by in-situ high temperature infrared spectroscopic analysis (DRIFTS) studies, which is followed by in-depth Density Functional Theory (DFT) calculations outline the plausible route via stabilisation of CHO∗, CH2O∗ intermediates for selective ethanol formation.

Long-life Li–S batteries based on enabling the immobilization and catalytic conversion of polysulfides

A novel hierarchical mesoporous nitrogen-rich carbon nanospheres comprising one-dimensional (1D) bamboo-like carbon nanotubes encapsulating Fe3O4 nanoparticles synthesized are used as a high-efficiency host for lithium–sulfur batteries.

Nitrogen-rich mesoporous carbon supported iron catalyst with superior activity for Fischer-Tropsch synthesis

Superior iron-based Fischer-Tropsch synthesis (FTS) catalysts (Fe/NMCs) were developed by impregnating high amount of iron (40 wt%) over nitrogen-rich mesoporous carbons (NMCs) with high porosities. The large pore volumes and specific surface areas of NMCs realized the high loadings and proper dispersions of iron while the nitrogen-containing groups enhanced the basicities of the catalysts. Weak metal-support interactions were observed in Fe/NMCs, which improved the reduction, carburization of iron, and further the FTS activities. FTS tests indicated a medium amount of nitrogen (≤8.3 wt%) did not show obvious effect on the activity of the catalyst, but a much higher amount of nitrogen (≥16.5 wt%) could result in a significant decrease of activity. Nitrogen-containing groups could effectively suppress the methane selectivity and improve the lower olefins selectivity in the FTS reaction. The hydrocarbon productivity of the Fe/NMCs was up to 0.62 g HC/(h·g cat.) at 260 °C, 1 MPa, and H2/CO ratio of 1, much higher than that of any other iron catalyst reported under similar conditions. As a result of the superior performance, Fe/NMCs could be one of ideal candidates for iron-based FTS catalysts in the future.

Au-Pd bimetallic nanoparticles supported on a high nitrogen-rich ordered mesoporous carbon as an efficient catalyst for room temperature Ullmann coupling of aryl chlorides in aqueous media.

An ionic liquid derived highly nitrogen-rich mesoporous carbon supported Au-Pd alloy was found to be an efficient and recyclable catalyst for the Ullmann coupling reaction of various aryl chlorides at room temperature in aqueous media.

Cu/Cu2O nanoparticle interface: Rational designing of a heterogeneous catalyst system for selective hydroamination

One pot highly uniform Cu(0)-Cu(I) oxide nanoparticles (5–10nm) have been synthesized on nitrogen rich mesoporous carbon nanospheres (Cu-NCN) and efficiently utilized as a heterogeneous catalyst towards hydroamination of aromatic terminal alkynes with aniline derivatives. The catalyst bed provides Cu2O nanoparticles stabilized by nitrogen functionalities in the carbon nanospheres, which triggers the catalytic system with significantly large Turn over number (TON) and >99% selectivity towards Markovnikov addition product. The structure and morphology of the copper nanoparticles engraved carbon spheres have been studied by performing nitrogen physisorption studies (BET), X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) characterization techniques.

High-surface-area and nitrogen-rich mesoporous carbon material from fishery waste for effective adsorption of methylene blue

A high quality nitrogen-rich mesoporous carbon material (FSAC) was prepared from carbonized fishery waste through chemical activation using NaOH. The obtained material had a high surface area of 1867m2/g, pore size of 2.5nm and mesopore volume of 0.38cm3/g. The adsorption efficiency of FSAC was examined for methylene blue (MB) removal from aqueous solution in batch method. The effects of initial concentration of dye (25–400mg/L), temperature (30–50°C) and pH (3−11) on the adsorption of MB on FSAC were studied. Evaluation of MB uptake by FSAC revealed that Langmuir isotherm and pseudo-second-order adsorption model adequately described the experimental data. The FSAC spontaneous and endothermic MB uptake at 30 °C gave high adsorption capacity of 184.40mg/g. These results show that FSAC can be used as an efficient and low cost adsorbent for cationic dye removal.

Creative utilization of natural nanocomposites: nitrogen-rich mesoporous carbon for a high-performance sodium ion battery

By creatively utilizing natural inorganic/organic nanocomposites, shrimp skin byproduct was easily converted to nitrogen-rich mesoporous carbon, a promising anode material that showed excellent electrochemical performance for sodium ion batteries.

Macroscopically shaped monolith of nanodiamonds @ nitrogen-enriched mesoporous carbon decorated SiC as a superior metal-free catalyst for the styrene production

Nanodiamonds (NDs) are recognized as a class of robust metal-free catalysts for the steam-free, direct dehydrogenation (DDH) of ethylbenzene (EB) to styrene (ST). In spite of that, some main drawbacks, such as their powdery form along with their tendency to form aggregates, limit their full exploitation at the industrial level. In this work, we describe the preparation of macroscopically shaped monoliths consisting of silicon carbide-based foams coated with a nitrogen-rich mesoporous carbon matrix (NMC) as a non-innocent glue for highly dispersed ND fillers. The NMC phase is prepared from cheap and non-toxic food-grade components and it prevents the undesired NDs agglomeration thus maximizing the reagents exposure throughout the catalytic DDH tests. Moreover, the NMC phase represents a key source of surface basicity capable of inhibiting the occurrence of EB cracking side reactions during the catalytic runs. As a result, the ND@NMC/SiC composite shows excellent dehydrogenation performance already at low ND loading if compared with the powdery NDs and/or the SiC-supported NDs of the state-of-the-art. Noteworthy, the ND@NMC/SiC composite presents its best catalytic performance under DDH conditions close to those used in industrial plants (reaction temperture up to 600°C and EB concentrations up to 10 vol.%) with high ST rates (λcatal. of 9.9mmolSTgcat−1h−1), ST selectivity over 96% and long term stability on stream.

Studies of synergy between metal–support interfaces and selective hydrogenation of HMF to DMF in water

Metal–support interfaces play a very important role in heterogeneous catalysis. The interfacial interactions not only are responsible for stabilizing the necessary oxidation state to facilitate the reaction but also enhance the stability of the catalyst system. Nano dispersion of Ni on mesoporous nitrogen-rich carbon material has been achieved using two different synthesis methods. It was observed that nickel (0) gets stabilized by strong interfacial interaction with the nitrogen atoms of the support material, and the material was found to be very economic and efficient for the conversion of HMF to DMF in aqueous medium. The material shows ⩾99% conversion to 5-(hydroxymethyl) furfural (HMF) within 6h of reaction with 98.7% DMF selectivity. A unique correlation between synthesis methods and particle sizes with catalytic performance has been observed for these newly developed materials. Furthermore, a DFT calculation has been performed to predict the reaction mechanism.

An efficient mesoporous carbon nitride (g-C3N4) functionalized Pd catalyst for carbon–carbon bond formation reactions

Pd-nanoparticles on mesoporous nitrogen-rich carbon nitride (MCN) serves as an efficient heterogeneous catalyst for Sonogashira cross-coupling reactions.

Nitrogen-Rich Mesoporous Carbon as Anode Material for High-Performance Sodium-Ion Batteries

Nitrogen-rich carbon with interconnected mesoporous structure has been simply prepared via a nano-CaCO3 template method, using polyaniline as carbon and nitrogen precursors. The preparation process includes in situ polymerization of aniline in a nano-CaCO3 aqueous solution, carbonization of the composites and removal of the template with diluted hydrochloric acid. Nitrogen sorption shows the carbon-enriched mesopores with a specific surface area of 113 m(2) g(-1). The X-ray photoelectron spectroscopy (XPS) analysis indicates that the carbon has a high nitrogen content of 7.78 at. %, in the forms of pyridinic and pyrrolic, as well as graphitic nitrogen. The nitrogen-rich mesoporous carbon shows a high reversible capacity of 338 mAh g(-1) at a current density of 30 mA g(-1), and good rate performance as well as ultralong cycling durability (110.7 mAh g(-1) at a current density of 500 mA g(-1) over 800 cycles). The excellent sodium storage performance of the nitrogen-rich mesoporous carbon is attributed to its disordered structure with large interlayer distance, interconnected porosity, and the enriched nitrogen heteroatoms.