Phosphorus-doped Carbon Nanotube Research Articles

Pt Loading of Phosphorus-Doped Carbon Nanotube Aerogels in Fuel Cell-Type Gas Sensors for Ultrasensitive H2 Detection.

A phosphorus-doped carbon nanotube (CNT) aerogel as the support material was loaded with Pt nanoparticles in fuel cell-type gas sensors for ultrasensitive H2 detection. The high surface area of the CNT scaffold is favorable to providing abundant active sites, and the high electrical conductivity facilitates the transport of carriers generated by electrochemical reactions. In addition, the CNT aerogel was doped with phosphorus (P) to further enhance the conductivity and electrochemical catalytic activity. As a result, the fuel cell-type gas sensor using the Pt/CNT aerogel doped with the optimal P content as the sensing material shows considerable performance for H2 detection at room temperature. The sensor exhibits an ultrahigh response of -921.9 μA to 15,000 ppm of H2. The sensitivity is -0.063 μA/ppm, which is 21 times higher than that of the conventional Pt/CF counterpart. The sensor also exhibits excellent repeatability and humidity resistance, as well as fast response/recovery; the response/recovery times are 31 and 4 s to 3000 ppm of H2, respectively. The modulation of the structure and catalytic properties of the support material is responsible for the improvement of the sensor performance, thus providing a feasible solution for optimizing the performance of fuel cell-type gas sensors.

Potential treatment of Parkinson's disease using new-generation carbon nanotubes: a biomolecular insilico study.

Background: One of the underlying mechanisms of Parkinson's diseaseis 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.

Phosphorus-doping activates carbon nanotubes for efficient electroreduction of nitrogen to ammonia

The electrochemical nitrogen reduction reaction (NRR) as an energy-efficient approach for ammonia synthesis is hampered by the low ammonia yield and ambiguous reaction mechanism. Herein, phosphorus-doped carbon nanotube (P-CNTs) is developed as an efficient metal-free electrocatalyst for NRR with a remarkable NH3 yield of 24.4 μg·h−1·mg−1cat. and partial current density of 0.61 mA·cm−2. Such superior activity is found to be from P doping and highly conjugated CNTs substrate. Experimental and theoretical investigations discover that the electron-deficient phosphorus sites with Lewis acidity should be genuine active sites and NRR on P-CNTs follows the distal pathway. These findings provide insightful understanding on NRR processes on P-CNTs, opening up opportunities for the rational design of highly-active cost-effective metal-free catalysts for electrochemical ammonia synthesis.

The adsorption mechanism of platinum on phosphorus-doped single walled carbon nanotube

Platinum nanoparticles on phosphorus-doped carbon materials exhibit high electrocatalytic activity and long-time stability as shown in recent experimental studies. In the present work, we use density functional theory calculations to study the adsorption nature of atomic platinum on phosphorus-doped carbon nanotube. Our calculation results demonstrate enhancement of the binding energy of Pt on P-doped CNT compared to pristine and nitrogen-doped CNTs. This increase in binding energy primarily results from the significant orbital hybridization between Pt sd hybridized orbital and P sp hybridized orbital.

Development of functionalized doped carbon nanotube/polysulfone nanofiltration membranes for fouling control

ABSTRACTThis work describes the fabrication of nitrogen doped and phosphorus doped carbon nanotube (fP‐CNT and fN‐CNT)/polysulfone blend membranes via a phase inversion method. The structural morphology, hydrophilicity, rejection, and permeability properties of the blend membranes were found to be dependent on the amount and type of functionalized CNTs (fCNTs) incorporated (i.e., fN‐CNTs, fP‐CNTs). The results showed that PSf membranes modified with P‐ or N‐doped CNTs have significantly improved hydrophilicity, thermal stability, water uptake, and surface charge compared to membranes modified with pristine fCNTs. Scanning electron microscopy studies demonstrated that the addition of the doped CNTs resulted in the formation of ‘finger‐like’ structures subsequently leading to increased membrane porosities and pore sizes. Thus, doped CNTs imparted on the transport mechanism of the parent membranes resulting in enhanced flow rates and better selectivity. This increase could be due to a combination of steric limitations from the carboxylic functional groups present in their surfaces leading to electrostatic repulsions between functional groups present in the membranes and the humic acid molecules. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41835.

A solvothermal synthesis of phosphorus doped carbon nanotube as a bi-functional electrocatalyst for oxygen reduction and oxygen evolution reaction

Electrocatalysts for the oxygen reduction and oxygen evolution reactions play a critical role in the performance of metal-air batteries. In this study, a phosphorus doped carbon nanotube (P-CNT) is facilely synthesized via a one-step process and in-situ solvothermal method. The electrocatalytic activity for the oxygen reduction reaction (ORR) and oxygen evolution reaction(OER) of the catalyst was studied with the rotating ring-disk electrode (RRDE) technique. The doping of phosphorus can obviously improve the electrocatalytic activity of CNT towards both the ORR and OER. Four electron reduction pathway is dominant on P-CNT during the ORR process, which is comparable to the commercial Pt/C (20 wt%). The electrocatalytic activity of P-CNT towards the OER is superior to that of Pt/C (20 wt%). Moreover, the long-term stability of P-CNT outperforms that of Pt/C (20 wt%). The high electrocatalytic activity and long-term stability of P-CNT are attributed to P-doping in CNT and the strong coupling between phosphorus and carbon.

Pt supported on phosphorus-doped carbon nanotube as an anode catalyst for direct methanol fuel cells

Phosphorus-doped multiwalled carbon nanotubes (P-MCNTs) were synthesized by thermolysis and employed as supports to prepare Pt/P-MCNTs catalyst for direct methanol fuel cells (DMFCs). Pt/P-MCNTs exhibited much higher electrocatalytic activity and longer-term stability for methanol oxidation than Pt/MCNTs in acidic medium, due to the higher dispersion and utilization rate and the improvement of intrinsic activity for methanol oxidation of Pt nanoparticles, indicating a highly potential application of Pt/P-MCNTs in DMFCs.