Bamboo-like Nitrogen-doped Carbon Nanotubes Research Articles

Bamboo-like nitrogen-doped carbon nanotubes directly grown from commercial carbon black for encapsulating FeCo nanoparticles as efficient oxygen reduction electrocatalysts

Efficient methods for preparing carbon nanotube (CNT)-confined metal catalysts are of great significance for electrocatalysis. Hence, in this study, Fe and Co promoters were added to the precursors of commercial carbon black and melamine to form N-doped CNTs confined bimetallic catalysts (FeCo@N-CNTs) via in situ pyrolysis. The FeCo@N-CNT catalysts exhibited a bamboo-like morphology with FeCo alloy nanoparticles encapsulated in the CNTs and high activity toward the oxygen reduction reaction, with a half-wave potential of 0.864 mV, higher than that of commercial Pt/C (0.827 mV) in alkaline solutions. The catalytic performance is attributable to the synergistic effects between the FeCo alloy and N-doped CNT structure. Moreover, the confinement of the FeCo nanoparticles inside the CNTs imparted the prepared catalysts with resistance to methanol poisoning and long-term stability. This versatile method of synthesizing CNTs directly from carbon black provides a new strategy for preparing high-performance non-precious-metal-based N-doped CNT catalysts for practical fuel cell applications.

Adding Fe/dicyandiamide to Co-MOF to greatly improve its ORR/OER bifunctional electrocatalytic activity

Exploring efficient non-precious metal oxygen electrocatalysts for oxygen reduction/evolution reactions (ORR/OER) is of great importance in electrochemical energy conversion devices like metal-air battery. Among them, carbon-based composites derived from metal-organic framework (MOF) exhibit excellent catalytic performance in ORR/OER. In this paper, Co-MOF-67 was firstly prepared, and then mixed with FeCl3·6 H2O and dicyandiamide, followed by a one-step pyrolysis to obtain bamboo-like nitrogen-doped carbon nanotubes. For the samples, Fe and Co nanoparticles were encapsulated in the front end of the carbon nanotubes and the presence of new (n)-diamond carbon was unexpectedly found. The obtained catalyst (FeCo@CNTs-60) has an onset potential of 1.04 V for ORR in alkaline solution, which is close to the commercial Pt/C (40 wt% Pt) of 1.05 V. The onset potential of 1.02 V in quasi-neutral solution exceeds that of Pt/C of 0.99 V. In addition, FeCo@CNTs-60 exhibited a low potential difference of 0.81 V between OER and ORR potentials. The alkaline zinc-air batteries, fabricated with the sample as the electrocatalyst of air electrode, exhibit higher peak power density and stability than Pt/C, while the rechargeable batteries present superior cycling discharge/charge stability at 5 mA·cm−2 and 10 mA·cm−2. In particular, the battery with FeCo@CNTs-60 was conducted for continuous over 1300 h of ultra long-term cycle charging / discharging test at a current density of 5 mA·cm−2, and it reveals excellent stability with high voltage efficiency and also presents superior cycle charging / discharging stability after replacing the Zn plates and electrolyte.

Co3C-stabilized-CoFe heterostructure wrapped by bamboo-like N-doped carbon nanotubes for highly-efficient oxygen electrocatalysis

Bimetallic alloys have been showing unexpectedly high activity for oxygen reduction reaction (ORR) in alkaline electrolytes. However, many fundamental questions regarding the ORR stability and poor oxygen evolution reaction (OER) performance of bimetallic alloys remain unresolved. Here, we prepare a cobalt carbide-stabilized CoFe alloy wrapped by hollow bamboo-like nitrogen-doped carbon nanotubes (CoFe-Co3C@NCNTs) using bimetallic Prussian-blue-analogue and dicyandiamide as precursors. Interestingly, the spherical CoFe-Co3C heterojunctions are always encapsulated at one end of the tube. The as-marked CoFe-Co3C@NCNTs-20 catalyst exhibits an ultra-high ORR activity (half-wave potential of 0.934 V) and a relatively good OER activity (overpotential of 0.320 V), which are superior to Pt/C and RuO2, respectively. CoFe-Co3C@NCNTs-20 also shows excellent ORR/OER stabilities and potential difference between ORR and OER (0.616 V). Excellent activity and stability benefit from the synergies between CoFe-Co3C and NCNTs, while the hollow structure/conductive skeleton enhances the mass/charge transfers, respectively. The NCNTs coating greatly enhances the stability of the CoFe-Co3C heterojunctions to avoid the corrosion of active sites in alkaline media. Moreover, rechargeable zinc-air battery assembled with CoFe-Co3C@NCNTs-20 cathode shows high power-density (209.15 mW cm−2) and open-circuit voltage (1.505 V). It provides a new reference for promoting the development of bimetallic alloy-coupled transition metal carbide catalysts.

Large-scale and solvent-free synthesis of magnetic bamboo-like nitrogen-doped carbon nanotubes with nickel active sites for photothermally driven CO2fixation

The development of a method for the large-scale and solvent-free preparation of hierarchical pore single-atom catalysts is highly desirable but challenging.

High polarity catalyst of CoFe alloy/fluoride interconnected by bamboo-like nitrogen-doped carbon nanotubes for efficient oxygen evolution reaction

The easy agglomeration and low conductivity of high polarity catalysts restrict the active phase formation for oxygen evolution reaction (OER) in water-splitting reactions, even for the catalysts with conductive NC species derived from MOFs carbonization. Herein, as a proof of concept, the bamboo-like nitrogen-doped carbon nanotube (N-doped CNT) from dicyandiamide pyrolysis was introduced into MOFs-derived high polarity catalyst of CoFe alloy and fluoride, and the performance for OER can be largely improved to low overpotentials of 231 mV to drive 10 mA cm−2 when loaded on the glassy carbon electrode. The structural evolution induced by the N-doped CNT introduction was carefully studied by both spectroscopic analysis and electrochemical measurements, and it was revealed that forming the structure of carbon nanotube interconnected active sites prevented the active site agglomeration and improved the catalytic conductivity, which improved the mass transfer, and active site exposure. The largely improved performance was attributed to the easy active phase formation by high polarity metal fluoride, the synergy between Fe and Co species, and conductivity improvement by N-doped carbon nanotubes derived from dicyandiamide with high graphitic N. The current work showed some novel contributions to catalytic ability boosting for MOF-derived catalysts in OER catalysis.

Bamboo-shaped Co@NCNTs as superior sulfur host for Li-S batteries

Functional and active carbon material is of great concern in facilitating the performance of lithium-sulfur (Li-S) battery. In this work, we develop a bamboo-like nitrogen-doped carbon nanotubes (Co@NCNTs-2) with low cobalt metal content, which acts as not only the host matrix for sulfur loading but also an efficient catalyst for the adsorption and conversion of lithium polysulfides (LiPSs). The characterization results show that the Co particles are mainly encapsulated inside the Co@NCNTs-2, and the N species are mainly distributed on the outer surface of Co@NCNTs-2. The Co particles are the growth sites of carbon nanotubes and are wrapped by carbon to form Co@NCNTs-2. It is confirmed that the uniform graphitized structure contributes to charge transfer, while the enriched N species assist the trap and catalytic conversion of the polysulfides, thus helping to restrain the shuttle effect. As a result, the resultant Co@NCNTs-2-S cathode presents high reversible capacity at different current densities and exhibits superior cycling stability for 300 cycles at 0.5 C.

Facile synthesis of bamboo-like Ni3S2@NCNT as efficient and stable electrocatalysts for non-enzymatic glucose detection

The rational design and controllable synthesis of metal–carbon composites as low cost and efficient catalysts have become the focus of research on non-enzymatic glucose detection. Herein, nickel sulfide nanocrystals encapsulated/dispersed by bamboo-like nitrogen-doped carbon nanotubes (Ni3S2@NCNT) are facilely synthesized by pyrolysis and sulfuration of Ni2+-dicyandiamide complex. During the pyrolysis, nickel nanoparticles are formed to promote the growth of NCNTs, while the NCNTs can disperse Ni nanoparticles to prevent them from oxidation and aggregations. The synergistic effects between Ni3S2 active sites and NCNTs also facilitate electronic transfer and enhance catalytic performances. Thus, Ni3S2@NCNT demonstrates excellent performances on glucose oxidation with unprecedented sensitivity (1447.64 μA mM−1 cm−2), low detection limit (0.14 μM), and wide linear range (0.46 μM-3.19 mM). Furthermore, as-fabricated sensors with superior performances indicate promising application prospects on non-enzymatic glucose detection in artificial sweat. This study will provide a general strategy for the controllable fabrication of catalysts with similar structures for other applications.

Pd Catalysts Supported on Bamboo-Like Nitrogen-Doped Carbon Nanotubes for Hydrogen Production

Bamboo-like nitrogen-doped carbon nanotubes (N-CNTs) were used to synthesize supported palladium catalysts (0.2–2 wt.%) for hydrogen production via gas phase formic acid decomposition. The beneficial role of nitrogen centers of N-CNTs in the formation of active isolated palladium ions and dispersed palladium nanoparticles was demonstrated. It was shown that although the surface layers of N-CNTs are enriched with graphitic nitrogen, palladium first interacts with accessible pyridinic centers of N-CNTs to form stable isolated palladium ions. The activity of Pd/N-CNTs catalysts is determined by the ionic capacity of N-CNTs and dispersion of metallic nanoparticles stabilized on the nitrogen centers. The maximum activity was observed for the 0.2% Pd/N-CNTs catalyst consisting of isolated palladium ions. A ten-fold increase in the concentration of supported palladium increased the contribution of metallic nanoparticles with a mean size of 1.3 nm and decreased the reaction rate by only a factor of 1.4.

Platinum quantum dots enhance electrocatalytic activity of bamboo-like nitrogen doped carbon nanotubes embedding Co-MnO nanoparticles for methanol/ethanol oxidation

Interaction of multi-active components can effectively maximize the overall catalytic ability of alcohol fuel cells. Herein, the self-assembled nitrogen doped carbon nanotubes (NCNTs) containing Co-MnO composite (Co-MnO/NCNTs) are successfully synthesized using dihydrodiamine as carbon and nitrogen source through one-step synthesis. In order to further improve the catalytic activity of Co-MnO/NCNTs for alcohol oxidation, small amounts of platinum quantum dots are uniformly loaded on Co-MnO/NCNTs formation of quaternary hybrid (named Pt/Co-MnO/NCNTs) during microwave reduction stage. Notably, the prepared Pt/Co-MnO/NCNTs hybrids possess the excellent methanol and ethanol oxidation mass current density of 1775.4 and 1112.8 mA mg−1 in alkaline condition, which are 3.6 and 2.25 times higher than that of Pt/C catalysts, respectively. The current density of ethanol catalytic oxidation is lower than that of methanol, which may be due to the partial oxidation of acetyl (the intermediate product of ethanol) on the Pt (1 1 1) crystal surface. More importantly, CO oxidation experiments reveal that strong electronic synergistic effect between MnO and Pt quantum dot can greatly improve the CO anti-poisoning ability. Another significant advantage of Pt/Co-MnO/NCNTs is that low platinum loading leads to low cost effective, which demonstrates that the modification non-noble metal catalysts with a few noble metals quantum dots is a promising choice to mass produce high performance catalyst with remarkably boosting electrocatalytic activity for alcohol oxidation.

Iron-Nanoparticle-Loaded Nitrogen-Doped Carbon Nanotube/Carbon Sheet Composites Derived from MOF as Electrocatalysts for an Oxygen Reduction Reaction

Exploring highly active, stable, and inexpensive electrocatalysts for the oxygen reduction reaction (ORR) is pivotal in developing high-performance energy conversion devices. Moreover, the production of catalysts containing transition metals with the appropriate nitrogen doping level is a potential approach to increase ORR catalytic efficiency, especially under acidic conditions. In this study, a hierarchical graphitic porous carbon-containing Fe and N was obtained via pyrolysis of a bimetal MOF (Fe/ZIF-8) composited with pyrrole. Further experimental and theoretical results confirmed that the synergistic effects between Fe-based nanoparticles and N-doping in the networks are likely form one of the main reasons for better ORR performance. Under optimized conditions, the resultant Fe-bNCNT/NC-900 (iron-based nanoparticles enwrapped in bamboo-like nitrogen-doped carbon nanotubes (bNCNTs) grown on N-doped sheet-like carbon) exhibits high electrocatalytic activity, high selectivity (direct 4e– reduction of oxygen to water), and stability in both acidic and alkaline electrolytes. Under acidic conditions, the half-wave potential (E1/2 = 0.770 VRHE) of Fe-bNCNT/NC-900 is comparable to commercial Pt/C (E1/2 = 0.800 VRHE). However, this catalyst shows better activity with a half-wave potential of 0.920 VRHE, which is more than Pt/C (E1/2 = 0.880 VRHE) in an alkaline electrolyte. The E1/2 of Fe-bNCNT/NC-900 under acidic and alkaline conditions experienced a 170 and 28 mV loss after 20 000 continuous cycles, and these results show the prepared catalyst has promising stability.

Bamboo-like nitrogen-doped carbon nanotubes on iron mesh for electrochemically-assisted catalytic oxidation

In this study, bamboo-like nitrogen-doped carbon nanotubes (BN-CNTs) are successfully deposited on etched iron mesh (d-Fe) using chemical vapor deposition (CVD) method with acetonitrile as precursor. The acidic etching process is necessary for the special BN-CNTs structure formation by exposing more Fe0 sites. The BN-CNTs/d-Fe is then evaluated for the electrochemically-assisted PMS activation to degrade phenol. Under cyclic voltammetry (CV, 0–1 V vs. RHE) assistant, 20 ppm phenol can be degraded in 30 min with a rate constant of 0.2837 min−1, ~78 times more than that without CV. Some Fe3+ species in the catalyst will be reduced at the initial stage, a two-step pseudo-first-order kinetic is thus used for the degradation curves fitting. Both the structure defects and doped nitrogen atoms are responsible for the high catalytic activity of BN-CNTs. According to the quenching tests, both radical and non-radical processes are present for PMS activation, thus obtaining enhanced organics removal efficiency. The electrochemically assistant could enhance the PMS adsorption on the electrode as well as electrons transfer between Fen+ and PMS, thus increasing the PMS activation efficiency. The utilization of earth-abundant Fe mesh for the fabricating free-standing electrodes provide a potential low-cost and effective strategy of waste water remediation.

Co nanoparticles coupling induced high catalytic activity of nitrogen doped carbon towards hydrogen evolution reaction in acidic/alkaline solutions

The development of highly-efficient and noble-metal-free catalysts with low cost and high durability for hydrogen evolution reaction (HER) is of great importance to many energy-related technologies. This work reports that nitrogen-doped carbon coated Co nanoparticles encapsulated in bamboo-like nitrogen-doped carbon nanotubes (Co@NC/B-NCNTs), synthesized by a simple calcination of Co(NO3)2, melamine and P123, is a promising catalyst for HER in both acidic and alkaline solutions. In acidic solution, the Co@NC/B-NCNTs has the HER onset potential of ∼0 V and only needs an overpotential of 7 mV to drive the current density of 10 mA cm−2. Its HER catalytic activity is very close to that of Pt/C. In alkaline solution, its onset potential and overpotential to drive 10 mA cm−2 are 100 and 182 mV, respectively. Both the values are lower than those of many other catalysts reported. The DFT calculations show electronic coupling between Co nanoparticles and NC layer plays an important role in high catalytic activity of Co@NC/B-NCNTs. The Co nanoparticles can change the charge density distribution of the outer NC layer, affecting its properties for hydrogen adsorption and desorption. Additionally, the pyridinic N in the outer NC layer is calculated to be a promising active site for HER.

Novel Fe3C Nanoparticles Encapsulated in Bamboo-Like Nitrogen-Doped Carbon Nanotubes as High-Performance Electrocatalyst for Zinc-Air Battery

In this paper, a novel material of Fe3C nanoparticles encapsulated inside the bamboo-like nitrogen-doped carbon nanotubes (Fe3C@b-NCNTs) is synthesized by pyrolysis of the mixture of iron salt and melamine-formaldehyde resin/SiO2 hybrid, and explored as the electrocatalyst for air-cathode of zinc-air battery. The morphology, structure and composition of Fe3C@b-NCNTs samples obtained at three different heat-treatment temperatures (700 °C, 800 °C, and 900 °C, respectively) are characterized by SEM, TEM, HR-TEM, HAADF-STEM, XRD, XPS, Raman and BET. Through electrochemical measurements using cyclic voltammetry, linear sweep voltammetry, and chronoamperometry, the oxygen reduction reaction (ORR) performance of such catalysts are evaluated. The obtained Fe3C@b-NCNTs-800 shows high and even better activity and stability than Pt/C catalyst. The excellent ORR performance of such catalyst can be ascribed to the bamboo-like nanotube structure, the adequate nitrogen doping level, and the synergistic effect between graphitic carbon layer and Fe3C nanoparticles. It is believed that the graphitic carbon layers can prevent Fe3C nanoparticles from agglomeration and protect Fe3C nanoparticles against electrolyte corrosion, while Fe3C nanoparticles activate the neighboring graphitic carbon layers and thus boost ORR activities. A rechargeable home-made zinc-air battery (ZAB) is assembled by using this catalyst for air cathode. The high performance of the assembled ZAB suggests that this Fe3C@b-NCNTs-800 catalyst is a promising electrcatalyst for metal-air batteries.

Bamboo-like nitrogen-doped carbon nanotubes encapsulated with NiFeP nanoparticles and their efficient catalysis in the oxygen evolution reaction

There is an urgent need to develop efficient, durable, earth-abundant, and low-cost electrocatalysts for the oxygen evolution reaction (OER) that occurs during the electrochemical splitting of water. Herein, we develop a method to synthesize uniform nitrogen-doped bamboo-like carbon nanotubes (NBCNT) encapsulated with NiFeP nanoparticles (NiFeP@NBCNT). When the as-fabricated nanocomposites are used to catalyze the OER, it exhibits exceptionally high activity in alkaline solution (180 mV @10 mA cm−2 and a low Tafel slope of 59 mV dec−1) and outstanding long-term stability. The turnover frequency (TOF) for NiFeP@NBCNT at an overpotential of 350 mV are calculated to 3.38 s−1. The OER reaction mechanism on the NiFeP@NBCNT modified electrode is explored by comparing the XPS spectra before and after electrochemical OER testing. The excellent catalytic properties make NiFeP@NBCNT a promising candidate for electrochemical catalysis in water splitting.

FeCo-Doped Hollow Bamboo-Like C-N Composites as Cathodic Catalysts for Zinc-Air Battery in Neutral Media

Precious metal-free C-N composites possess great significance as replacements for Pt-based catalysts used as cathodes in fuel cells. Herein, we have fabricated the Fe/Co-doped C-N composite catalysts, marked as C-N, Co/C-N and Fe-Co/C-N, by direct pyrolysis of the dried suspensions consisting of cobalt/iron salt, dicyandiamide and glucose. For the Fe-Co/C-N catalyst, its morphological texture is characterized by Fe-Co nanoparticles and hollow bamboo-like nitrogen-doped carbon nanotubes (C-N nanotubes). The electroactivity of the prepared samples for oxygen reduction reaction (ORR) in a neutral medium has been investigated. The catalyst Fe-Co/C-N presents the highest ORR current density of 5.1 mA·cm−2 @0.8V (vs Ag/AgCl) in a neutral medium. A zinc-air battery in neutral KNO3 solution, assembled with zinc as the anode and carbon paper loaded by the prepared catalysts as the air electrode (cathode), displays excellent and stable discharge performance. The maximum power density of the Fe-Co/C-N catalyst is 32 mW·cm−2, and the continuous discharge time reaches 209, 155, 17 h at constant discharging current density of 25, 50 and 100 mA·cm−2 respectively. Simultaneously, the air electrode using the Fe-Co/C-N as the catalyst shows good cycle stability and repeatability. Results reveal that the Fe-Co/C-N is a very promising cathodic catalyst applied in neutral zinc-air battery.

Efficient electrocatalysis of hydrogen evolution by ultralow-Pt-loading bamboo-like nitrogen-doped carbon nanotubes

The highly effective catalysts for the electrochemical hydrogen generation with substantially reduced cost are strongly desirable, but difficult to achieve. The reduction of Pt-loading by downsizing the Pt nanoparticles is an efficient strategy for obtaining low-cost and high-activity HER electrocatalysts. Herein, we describe a facile strategy to the formation of ultrafine Pt nanoparticles (NPs) bonding to N-doped bamboo-like carbon nanotubes, serving as a highly active and durable catalyst with ultra-low Pt loading for the electrochemical hydrogen generation. With the addition of mesoporous silica to change the wettability of the electrode from hydrophobicity to hydrophilicity of the electrode, the optimized nanocomposite catalyst with ultra-low Pt loading (0.74 wt%) shows a near-zero onset potential (Uonset), an extremely low overpotential of 40 mV to reach 10 mA cm−2 (η10), a small Tafel slope of 33 mV dec−1, and excellent long-term stability, which are comparable to those of 20 wt% Pt/C catalyst. The outstanding properties ensure this promising nanocomposite with significantly reduced Pt loading to become one of the most active catalysts towards the electrochemical hydrogen generation in acid medium.

Structural analysis and oxygen reduction reaction activity in bamboo-like nitrogen-doped carbon nanotubes containing localized nitrogen in nodal regions

Nitrogen-doped carbon nanotubes (N-CNTs) act as a metal-free catalyst for oxygen reduction reaction (ORR), but improving the ORR activity of N-CNTs remains challenging due to a lack of structural information. The N-CNTs with higher nitrogen concentration (an average surface nitrogen concentrations, 14.3 at.%) than the N-CNTs fabricated by conventional chemical vapor deposition method were synthesized using a dielectric barrier discharge in high pressure nitrogen and the spatial distribution of nitrogen in the N-CNTs was demonstrated by transmission electron microscopy in conjunction with electron energy loss spectroscopy. Nitrogen atoms were found to be concentrated at nodal regions in the bamboo-like structure, at concentrations above 23 at.%. At the point of the ORR, the highest onset potential was observed in the N-CNTs due to relatively highly incorporated pyridine-like nitrogen.

Bamboo-like nitrogen-doped carbon nanotubes formed by direct pyrolysis of Prussian blue analogue as a counter electrode material for dye-sensitized solar cells

Nitrogen-doped carbon materials were prepared by direct pyrolysis of nanostructured Prussian blue analogue (metal hexacyanoferrates) without additional carbon sources and metal catalysts. The pyrolysis temperature played a crucial role in determining the structure of resultant carbon materials. Bamboo-like nitrogen-doped carbon nanotubes (NCNTs) could be formed at a pyrolysis temperature of 700°C, while only the nitrogen-doped carbon spheres (NCNSs) were obtained at 500°C. After removal of metal catalysts, the bamboo-like NCNTs exhibited superior electrocatalytic behavior towards I−/I3− than the hollow NCNSs, primarily due to their higher surface area and electrical conductivity in comparison with NCNSs. The photoelectron conversion efficiency of dye-sensitized solar cell (DSC) using NCNT counter electrode reached 7.48%, which was even better than that using Pt counter (7.12%) and much higher than that using NCNS counter (5.53%). The improved photovoltaic performance of DSC employing metal-free NCNT counter electrode was primarily attributed to the significantly reduced diffusion and charge-transfer resistances in porous NCNT catalyst layer in comparison with the compact NCNS electrode.

Core-shell Co@Co3O4 nanoparticle-embedded bamboo-like nitrogen-doped carbon nanotubes (BNCNTs) as a highly active electrocatalyst for the oxygen reduction reaction.

The current bottleneck for fuel cells and metal-air batteries lies in the sluggish oxygen reduction reaction (ORR) on the cathode side. Despite tremendous efforts, to develop a highly efficient ORR catalyst at low cost remains a great challenge. Herein, we have synthesized core-shell Co@Co3O4 nanoparticles embedded in the bamboo-like N-doped carbon tubes (BNCNTs) by a simple approach comprising thermal treatment of cobalt carbonate hydroxide and urea and oxidization. The ORR catalytic activities of the Co@Co3O4/BNCNT composites are closely dependent on the oxidization degree of the Co nanoparticles and the N content in the BNCNTs. When oxidized at 300 °C, the as-formed Co@Co3O4/BNCNTs-300 composite catalyst with an N/C molar ratio of ∼ 1.6% achieves the maximum ORR catalytic activity. The composite catalyst also exhibits a higher ORR catalytic activity than the Co3O4/carbon nanotube (CNT) catalyst. The tolerance for methanol molecules and the cycle stability performance of the composite catalyst are even superior to those of the highly efficient Pt/C catalyst. Such an excellent ORR catalytic activity can be ascribed to (1) the core-shell Co@Co3O4 nanoparticles embedded in BNCNTs, (2) the N-doping in BNCNTs, and (3) the synergetic effect of (1) and (2) on Co3O4 firmly attached to both Co nanoparticles and BNCNTs, resulting in accelerated electron transport and enhanced charge delocalization.

Bamboo-like nitrogen-doped carbon nanotubes toward fluorescence recovery assay for DNA detection

Pyrolysis of melamine/CoCl2·6H2O mixture under Ar followed by acid leaching results in the formation of a large amount of bamboo-like nitrogen-doped carbon nanotubes (NCNTs). When used as a novel sensing platform toward fluorescence recovery assay for DNA detection, the NCNTs show a low detection limit of 5nM and a high selectivity down to single-base mismatch.