Ultrasonication-aided synthesis of nanoplates-like iron molybdate: Fabricated over glassy carbon electrode as an modified electrode for the selective determination of first generation antihistamine drug promethazine hydrochloride

The innovation of novel and proficient nanostructured materials for the precise level determination of pharmaceuticals in biological fluids is quite crucial to the researchers. With this in mind, we synthesized iron molybdate nanoplates (Fe₂(MoO₄)₃; FeMo NPs) via simple ultrasonic-assisted technique (70 kHz with a power of 100 W). The FeMo NPs were used as the efficient electrocatalyst for electrochemical oxidation of first-generation antihistamine drug- Promethazine hydrochloride (PMH). The as-synthesized FeMo NPs were characterized and confirmed by various characterization techniques such as XRD, Raman, FT-IR, FE-SEM, EDX and Elemental mapping analysis and electron impedance spectroscopy (EIS). In addition, the electrochemical characteristic features of FeMo NPs were scrutinized by electrochemical techniques like cyclic voltammetry (CV) and differential pulse voltammetry technique (DPV). Interestingly, the developed FeMo NPs modified glassy carbon electrode (FeMo NPs/GCE) discloses higher peak current with lesser anodic potential on comparing to bare GCE including wider linear range (0.01–68.65 µM), lower detection limit (0.01 µM) and greater sensitivity (0.97 µAµM^-1cm⁻²). Moreover, the as-synthesized FeMo NPs applied for selectivity, reproducibility, repeatability and storage ability to investigate the practical viability. In the presence of interfering species like cationic, anionic and biological samples, the oxidation peak current response doesn’t cause any variation results disclose good selectivity towards the detection of PMH. Additionally, the practical feasibility of the FeMo NPs/GCE was tested by real samples like, commercial tablet (Phenergan 25 mg Tablets) and lake water samples which give satisfactory recovery results. All the above consequences made clear that the proposed sensor FeMo NPs/GCE exhibits excellent electrochemical behavior for electrochemical determination towards oxidation of antihistamine drug PMH.     

Sonochemical synthesis of nickel-manganous oxide nanocrumbs decorated partially reduced graphene oxide for efficient electrochemical reduction of metronidazole

In the present work, we report on the synthesis of crump-like nickel manganous oxide nanoparticles decorated partially reduced graphene oxide (NiMnO@pr-GO) nanocomposite through high-intensity ultrasonic bath sonication (ultrasonic frequency = 37 kHz and power = 150 W). The NiMnO@pr-GO nanocomposite modified glassy carbon electrode (GCE) was then employed for the electrochemical reduction of detrimental metronidazole (MNZ). The crystalline phase and formation of the NiMnO@pr-GO nanocomposites were confirmed by X-ray diffraction and other spectroscopic techniques. The cyclic voltammetry results demonstrate that this NiMnO@pr-GO nanocomposite modified GCE has a lower reduction potential and higher catalytic activity towards MNZ than do NiMnO and GO modified GCEs. Under optimized conditions, the fabricated NiMnO@pr-GO electrode can detect metronidazole over a wide linear range with a lower limit of detection of 90 nM. The sensitivity of the sensor was 1.22 µA µM^-1cm⁻² and was found to have excellent selectivity and durability for the detection of MNZ.     

Sonochemical synthesis and fabrication of perovskite type calcium titanate interfacial nanostructure supported on graphene oxide sheets as a highly efficient electrocatalyst for electrochemical detection of chemotherapeutic drug

In green approaches for electrocatalyst synthesis, sonochemical methods play a powerful role in delivering the abundant surface areas and nano-crystalline properties that are advantageous to electrocatalytic detection. In this article, we proposed the sphere-like and perovskite type of bimetal oxides which are synthesized through an uncomplicated sonochemical procedure. As a yield, the novel calcium titanate (orthorhombic nature) nanoparticles (CaTiO₃ NPs) decorated graphene oxide sheets (GOS) were obtained through simple ultrasonic irradiation by a high-intensity ultrasonic probe (Titanium horn; 50 kHz and 60 W). The GOS/CaTiO₃ NC were characterized morphologically and chemically through the analytical methods (SEM, XRD, and EDS). Besides, as-prepared nanocomposites were modified on a GCE (glassy carbon electrode) and applied towards electrocatalytic and electrochemical sensing of chemotherapeutic drug flutamide (FD). Notably, FD is a crucial anticancer drug and also a non-steroidal anti-androgen chemical. Mainly, the designed and modified sensor has shown a wide linear range (0.015–1184 µM). A limit of detection was calculated as nanomolar level (5.7 nM) and sensitivity of the electrode is 1.073 μA μM⁻¹ cm⁻². The GOS/CaTiO₃ modified electrodes have been tested in human blood and urine samples towards anticancer drug detection.     

Ultrasonication and hydrothermal assisted synthesis of cloud-like zinc molybdate nanospheres for enhanced detection of flutamide

Ultrasonication is one of the emerging probes for nanoparticles synthesis as well as promoting the material property by treasuring the precious time during a chemical reaction. In this present work, we successfully designed a cloud-like α-ZnMoO₄ nanospheres (ZMNS) using ultrasound assistance (bath sonication with the power of 60 W and frequency of 37/80 kHz) hydrothermal method for catalyzing the effective electrochemical determination of anti-androgen drug candidate flutamide (FLT). The crystallinity and phase purity were investigated using powder X-ray diffractometric analysis. The FTIR and Raman spectra information were compared to detect the possible bonding in ZMNS. The texture and surface morphology were studied using Field emission scanning electron microscope and High-resolution Transmission electron microscope images. The presence of the elements (Zn, Mo and O) and the absence of any other impurities were monitored and confirmed using EDAX analysis. The fabrication of ZMNS modified GCE was performed carefully. Additionally, the ZMNS modified glassy carbon electrode (GCE) exhibits superior electrocatalytic activity by means of higher cathodic peak current towards the detection of FLT. The fashioned electrode attained two wide linear response ranges (0.1 to 73 µM; 111 to 1026 µM) with a lower detection limit of about 33 nM correspondingly. Furthermore, the fabricated sensor displayed excellent sensitivity of 1.095 µA µM⁻¹ cm⁻² and good selectivity for FLT sensing even in the existence of similar interfering compounds and biomolecules. Along with that, the designed sensor executed noticeable reproducibility, repeatability, and enduring stability.     

Synthesis of novel amperometric urea-sensor using hybrid synthesized NiO-NPs/GO modified GCE in aqueous solution of cetrimonium bromide

In this study NiO nanostructures were synthesized via combinational synthetic method (ultrasound-assisted biosynthesis) and immobilized on the glassy carbon electrode (GCE) as a highly sensitive and selective enzyme-less sensor for urea detection. NiO-NPs were fully characterized using SEM, EDX, XRD, BET, TGA, FT-IR, UV–vis and Raman methods which revealed the formation of NiO nanostructures in the form of cotton like porous material and crystalline in nature with the average size of 3.8 nm. GCE was modified with NiO-NPs in aqueous solution of cetrimonium bromide(CTAB). Highly adhesive NiO/CTAB/GO nanocomposite membrane has been formed on GCE by immersing NiO/CTAB modified GCE in GO suspension. CTAB has a major role in the production and immobilization of the nanocomposites on the GCE surface and the binding NiO nanoparticles on GO plates. In addition, CTAB/GO composition made a highly adhesive surface on the GCE. The resulting NiO/CTAB/GO/GCE contains potently sensitive to urea in aqueous environments. The response of as developed amperometric sensor was linear in the range of 100–1200 µM urea with R² value of 0.991 and limit of detection (LOD), 8 µM. The sensor responded negligibly to various interfering species like glucose, uric acid and ascorbic acid. This sensor was applied successfully for determining urea in real water samples such as mineral water, tap water and river water with acceptable recovery.     

Simple sonochemical synthesis of novel grass-like vanadium disulfide: A viable non-enzymatic electrochemical sensor for the detection of hydrogen peroxide

Design and fabrication of novel inorganic nanomaterials for the low-level detection of food preservative chemicals significant is of interest to the researchers. In the present work, we have developed a novel grass-like vanadium disulfide (GL-VS₂) through a simple sonochemical method without surfactants or templates. As-prepared VS₂ was used as an electrocatalyst for reduction of hydrogen peroxide (H₂O₂). The crystalline nature, surface morphology, elemental compositions and binding energy of the as-prepared VS₂ were analyzed by X-ray diffraction, Raman spectroscopy, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. The electrochemical studies show that the GL-VS₂ modified glassy carbon electrode (GL-VS₂/GCE) has a superior electrocatalytic activity and lower-reduction potential than the response observed for unmodified GCE. Furthermore, the GL-VS₂/GCE displayed a wide linear response range (0.1–260 μM), high sensitivity (0.23 μA μM⁻¹ cm⁻²), lower detection limit (26 nM) and excellent selectivity for detection of H₂O₂. The fabricated GL-VS₂/GCE showed excellent practical ability for detection of H₂O₂ in milk and urine samples, revealing the real-time practical applicability of the sensor in food contaminants.     

Sonochemical synthesis and fabrication of neodymium sesquioxide entrapped with graphene oxide based hierarchical nanocomposite for highly sensitive electrochemical sensor of anti-cancer (raloxifene) drug

The ultrasound-assisted synthesis of a novel neodymium sesquioxide nanoparticles (Nd₂O₅ NPs) decorated graphene oxide (GO) nanocomposite under ultrasonic probe (Ultrasonic processor model-PR 1000; frequency-30 kHz; power of 100 W/cm²) has been reported. After then, SEM, TEM, XRD, EDX and electrochemical impedance spectroscopy characterized was analyzed using Nd₂O₅ NPs@GO nanomaterial. Furthermore, the nanomaterial modified GCE (glassy carbon electrode) shows excellent electrochemical sensing performance towards anti-cancer drug. Raloxifene is one of the important anti-cancer drug. Moreover, the fabricated electrochemical sensor has showed a wide linear range for raloxifene between 0.03 and 472.5 µM and nanomolar detection limit (18.43 nM). In addition, the Nd₂O₅ NPs@GO modified sensor has been applied to the determination of raloxifene in human blood and urine samples.     

Sonochemical synthesis of novel thermo-responsive polymer and tungsten dioxide composite for the temperature-controlled reversible “on-off” electrochemical detection of β-Blocker metoprolol

Thermo-responsive polymer nanocomposite based on poly (styrene-co-N-isopropylacrylamide) hybrid tungsten dioxide (WO₂@PS-co-PNIPAM) was synthesized by a facile ultrasonic irradiation (Frequency; 20 kHz, power; 180 W, calorimetrically determined power; 5.73 W in the bath, and Type; probe) method in the presence of water as inisolv. The as-synthesized WO₂@PS-co-PNIPAM modified glassy carbon electrode (WO₂@PS-co-PNIPAM/GCE) was acting as a reversibly switched detection for the electrooxidation of metoprolol (MTP), with the thermal stimuli response of the PNIPAM. In below lower critical solution temperature (LCST), the PS-co-PNIPAM expanded to embed the electroactive sites of WO₂, and the MTP could not proceed via the polymer to attain electronic transfer, indicating the “off” state. Rather, in above LCST, the PS-co-PNIPAM shrank to reveal electroactive sites and expand cyclic voltammetric background peak currents, the MTP was capable to undergo electro-oxidation reaction usually and produce the response current, indicating “on” state. Additionally, the proposed sensor had excellent sensitivity (2.21 µA µM⁻¹ cm⁻²), wide dynamic range (0.05–306 µM), and a low limit of detection of 0.03 µM for MTP. Intriguingly, the fabricated sensor demonstrates the good selectivity towards the detection of MTP among the possible interfering compounds. Eventually, the WO₂@PS-co-PNIPAM/GCE has been utilized in the analysis of MTP in human blood serum samples.     

Nitrobenzene electrochemical sensor based on silver nanoparticle supported on poly-melamine functional multi-walled carbon nanotube

A novel and convenient electrochemical sensor, based on multi-walled carbon nanotube (MWCNT)–poly-melamine(PMel)–silver nanoparticle (AgNP) composite-modified glassy carbon electrode (GCE), was fabricated for the determination of nitrobenzene (NB). The modified electrode not only played an efficient electrocatalytic role for the reduction of NB but also significantly reduced the overpotential of NB, and the peak current increased greatly compared with bare GCE or other modified electrodes. The excellent performance of NB sensor can be ascribed to the synergistic effect between MWCNT and AgNP. The synergistic effect promoted the electron transfer between MWCNT and AgNP significantly and enhanced the electrochemical reduction ability of NB remarkably. Besides, PMel has huge nitrogen and amine groups, which contributes to the dispersion of silver nanoparticles and also improves the electrocatalytic activity and sensitivity of the sensor. The integration of PMel/MWCNT with AgNP provided a high-performance platform for the NB determination. Under the optimized experimental conditions, the developed sensor showed a wide linear calibration ranges from 20 to 1000 μM and from 1000 to 6000 μM, with a low detection limit (0.55 μM) for the detection of NB. At the same time, the modified electrode exhibited good stability and reproducibility and acceptable selectivity. Moreover, the proposed sensors were successfully employed to determine NB in real samples, and the recoveries were between 97.2 and 104.6 %.     

Ultrasound-assisted facile one-pot synthesis of ternary MWCNT/MnO2/rGO nanocomposite for high performance supercapacitors with commercial-level mass loadings

Commercial application of supercapacitors (SCs) requires high mass loading electrodes simultaneously with high energy density and long cycle life. Herein, we have reported a ternary multi-walled carbon nanotube (MWCNT)/MnO₂/reduced graphene oxide (rGO) nanocomposite for SCs with commercial-level mass loadings. The ternary nanocomposite was synthesized using a facile ultrasound-assisted one-pot method. The symmetric SC fabricated with ternary MWCNT/MnO₂/rGO nanocomposite demonstrated marked enhancement in capacitive performance as compared to those with binary nanocomposites (MnO₂/rGO and MnO₂/MWCNT). The synergistic effect from simultaneous growth of MnO₂ on the graphene and MWCNTs under ultrasonic irradiation resulted in the formation of a porous ternary structure with efficient ion diffusion channels and high electrochemically active surface area. The symmetric SC with commercial-level mass loading electrodes (∼12 mg cm⁻²) offered a high specific capacitance (314.6 F g⁻¹) and energy density (21.1 W h kg⁻¹ at 150 W kg⁻¹) at a wide operating voltage of 1.5 V. Moreover, the SC exhibits no loss of capacitance after 5000 charge−discharge cycles showcasing excellent cycle life.     

Facile sonochemical synthesis of rutile-type titanium dioxide microspheres decorated graphene oxide composite for efficient electrochemical sensor

In this reports the facile and green synthesis of rutile-type titanium dioxide nanoparticles decorated graphene oxide nanocomposite via the ultrasonication process (frequency: 50 kHz, Power: 100 W/cm² and Ultrasonic type: Ti-horn). Because, the sonochemical synthesis method is simple, non-explosive and harmless method than other conventional technique. Furthermore, the synthesized material was characterized by various analytical techniques including FESEM, EDX, XRD, EIS and electrochemical methods. Then, the synthesized TiO₂ MPs@GOS composite was applied for the electrocatalytic detection of theophylline (TPL) using CV and amperometric (current-time) techniques. Captivatingly, the modified sensor has excellent electrocatalytic performance with the wider linear range from 0.02 to 209.6 µM towards the determination of theophylline and the LOD and sensitivity of the modified sensor was calculated as 13.26 nM and 1.183 μA·µM⁻¹·cm⁻², respectively. In addition, a selectivity, reproducibility and stability of the TiO₂ MPs@GOS modified GCE were analyzed towards the determination of theophylline molecule. Finally, the real time application of TiO₂ MPs@GOS modified theophylline sensor was established in serum and drug samples.     

Layered nanocomposite of zinc sulfide covered reduced graphene oxide and their implications for electrocatalytic applications

Herein, we have synthesized zinc sulfide nanospheres (ZnS NPs) encapsulated on reduced graphene oxide (RGO) hybrid by an ultrasonic bath (50 kHz/60 W). The physical and structural properties of ZnS NPs@RGO hybrid were analyzed by TEM, XRD, EIS and EDS. As-prepared ZnS NPs@RGO hybrid was applied towards the electrochemical determination of caffeic acid (CA) in various food samples. The ZnS NPs@RGO hybrid modified electrode (GCE) exhibited an excellent electrocatalytic performance towards caffeic acid detection and determination, when compared to other modified electrodes. Therefore, the electrochemical sensing performance of the fabricated and nanocomposite modified electrode was significantly improved owing to the synergistic effect of ZnS NPs and RGO catalyst. Furthermore, the hybrid materials provide highly active electro-sites as well as rapid electron transport pathways. The proposed electrochemical caffeic acid sensor produces a wide linear range of 0.015–671.7 µM with a nanomolar level detection limit (3.29 nM). In addition, the real sample analysis of the proposed sensor has applied to the determination of caffeic acid in various food samples.     

Green sonochemical synthesis and fabrication of cubic MnFe2O4 electrocatalyst decorated carbon nitride nanohybrid for neurotransmitter detection in serum samples

The binary nanomaterials and graphitic carbon based hybrid has been developed as an important porous nanomaterial for fabricating electrode with applications in non-enzymatic (bio) sensors. We report a fast synthesis of bimetal oxide particles of nano-sized manganese ferrite (MnFe₂O₄) decorated on graphitic carbon nitride (GCN) via a high-intensity ultrasonic irradiation method for C (30 kHz and 70 W/cm²). The nanocomposites were analyzed by powder X-ray diffraction, XPS, EDS, TEM to ascertain the effects of synthesis parameters on structure, and morphology. The MnFe₂O₄/GCN modified electrode demonstrated superior electrocatalytic activity toward the neurotransmitter (5-hydroxytryptamine) detection with a high peak intensity at +0.21 V. The appealing application of the MnFe₂O₄/GCN/GCE as neurotransmitter sensors is presented and a possible sensing mechanism is analyzed. The constructed electrochemical sensor for the detection of 5-hydroxytryptamine (STN) showed a wide working range (0.1–522.6 μM), high sensitivity (19.377 μA μM⁻¹ cm⁻²), and nano-molar detection limit (3.1 nM). Moreover, it is worth noting that the MnFe₂O₄/GCN not only enhanced activity and also promoted the electron transfer rate towards STN detection. The proposed sensor was analyzed for its real-time applications to the detection of STN in rat brain serum, and human blood serum in good satisfactory results was obtained. The results showed promising reproducibility, repeatability, and high stability for neurotransmitter detection in biological samples.     

Sonochemical synthesis and anchoring of zinc oxide on hemin-mediated multiwalled carbon nanotubes-cellulose nanocomposite for ultra-sensitive biosensing of H2O2

In this work, the metal oxide and biopolymer nanocomposites on multiwalled carbon nanotubes (MWCNT) were prepared using a simple sonochemical method. The hexagonal nanorods of zinc oxide (ZnO NR) were synthesized by probe sonication (frequency = 20 kHz, amplitude = 50) method and were integrated on ultrasonically functionalized MWCNT-cellulose nanocrystals (MWCNT-CNC) for the first time. The stable hemin bio-composites also were prepared using the bath sonication (37 kHz of frequency, 150 W of power) method, and was used for the selective and ultrasensitive electrochemical detection of H₂O₂. The UV–Vis spectroscopy studies confirmed the presence of native hemin on MWCNT-CNC/ZnO NR nanocomposite. Cyclic voltammetry studies revealed that an enhanced redox electrochemical behaviour of hemin was observed on hemin immobilised MWCNT-CNC/ZnO NR nanocomposite than that of other hemin modified electrodes. Also, the MWCNT-CNC/ZnO NR/hemin modified SPCE showed 2.3 folds higher electrocatalytic activity with a lower reduction potential (−0.2 V) towards H₂O₂ than that of other investigated hemin modified electrodes including hemin/MWCNT and hemin/CNC-ZnO. The fabricated biosensor displayed a stable amperometric response (-0.2 V vs Ag/AgCl) in the linear concentration of H₂O₂ ranging up to 4183.3 µM with a lower detection limit of 4.0 nM.     

Synthesis and comparative study of optical and electrical properties of Au-doped carbon nanotubes prepared in different reaction media

We introduce the synthesis, characterization and physical properties of gold (Au) doped multiwalled carbon nanotubes (MWCNTs) in different reaction media. In order to dope MWCNTs with Au nanoparticles (NPs), first functionalized carbon nanotubes (f-MWCNTs) were prepared. The reduction of gold (III) chloride trihydrate for synthesizing Au NPs in the presence of f-MWCNTs was performed by using sodium citrate as a reducing agent. The produced nanocomposites were characterized using FTIR, XRD and TEM analyses to explore their chemical structures and morphologies. All of the samples have been characterized by TGA and resultantly, the composite made into ethylene glycol exhibited the most concentration of Au NPs into the composite network. This work probes the optical characteristics, such as UV–vis absorption, and optical band gap. Hall effect analyses declared some pleasing variations in electrical characteristics. Remarkably, the n-type doping of Au NPs in the p-type MWCNTs’ network led to a downshift of the Fermi level. This process increased the doped samples electrical conductivity. The results indicated that modification of MWCNTs with Au NPs has generally an important role in decreasing the band gap and increasing the electrical activity of MWCNTs. Our research outcomes provide a new vision into how different reaction media could affect the characteristics of MWCNT/Au nanocomposites. We discovered that ethylene glycol could be considered as a perfect reaction medium for preparation of high-quality doped CNTs with excellent physical properties. Our effort opens up the door to far more investigations on the role of the reaction medium in products’ characteristics.     

Contact resistance of multi-walled carbon nanotube/natural rubber nanocomposites with metallic ball

This paper reports on the contact resistance (R_c) between carbon filler/natural rubber (NR) nanocomposite and gold ball: three varieties of nanocomposites were prepared from carbon black (CB) and two kinds of multi-walled carbon nanotubes (MWCNTs) with different diameter. R_c of MWCNT/NR nanocomposite was remarkably less than that of CB/NR nanocomposites. The relationship between R_c of MWCNT/NR nanocomposites and applied load was expressed in the formula, R_c=C·P⁻ⁿ (P: load, C and n: constant): for the MWCNTs (diameters of 13 nm)/NR and MWCNTs (diameters of 67 nm)/ NR nanocomposites, they were expressed as R_c=1724·P^−0.6 and R_c=344·P^−0.37, respectively. The former (MWCNT, ϕ13 nm) showed higher R_c than the latter (MWCNT, ϕ67 nm) over whole region of applied load. The mechanical hardness of the former was higher (90 HsA) than that of the latter (82 HsA). Therefore, the smaller contact area between the nanocomposite and gold ball of the former resulted in higher R_c. The apparent specific contact resistivity was calculated from the observed values of R_c and contact area: 130 Ω mm² and 127 Ω mm² for the former (MWCNT, ϕ13 nm) and the latter (MWCNT, ϕ67 nm), respectively.     

A feasible sonochemical approach to synthesize CuO@CeO2 nanomaterial and their enhanced non-enzymatic sensor performance towards neurotransmitter

A nanostructured and high conductive cupric oxide (CuO NPs) with hierarchical CeO₂ sheets-like structure was synthesized by a facile sonochemical approach. Furthermore, CuO/CeO₂ nanostructure is synthesized by high-intensity ultrasonic probe (Ti-horn, 50 kHz and 100 W) at ambient air. Moreover, the synthesized CuO/CeO₂ material was characterized by various analytical techniques including FESEM, EDX, XRD and electrochemical methods. Then, the synthesized CuO/CeO₂ composite was applied for the electrocatalytic detection of dopamine using CV and DPV techniques. In addition, the CuO/CeO₂ modified electrode has good electrocatalytic performance with high linear range from 0.025 to 98.5 µM towards the determination of dopamine drug and high sensitivity of the CuO/CeO₂ modified drug sensor was calculated as 16.34 nM and 4.823 μA·µM⁻¹·cm⁻², respectively. Moreover, a repeatability, reproducibility and stability of the CuO@CeO₂ mixture modified electrode were analyzed towards the determination of dopamine biomolecule. Interestingly, the real time application of CuO@CeO₂ modified electrode was established in different serum and drug samples.     

Viscoelastic and Dielectric Behavior of Poly(1‐Butene)/Multiwalled Carbon Nanotube Nanocomposites

Linear viscoelastic properties and dielectric behavior of poly(1‐butene)/multiwalled carbon nanotube (MWCNT) nanocomposites were investigated. Dynamic mechanical analysis showed significant increase in storage modulus in the rubbery regime. The tan δ peak temperature remained constant; however, the peak intensity was lowered for the nanocomposites. In melt rheological studies the nanocomposites showed a shift in crossover frequency to the lower side, suggesting delayed relaxation of the molecular chains in the presence of MWCNT and this shift was found to depend on the content of MWCNT. The dielectric constant increased from 2.2 to 70 for the nanocomposite with 7 wt. % MWCNT. The electrical conductivity increased significantly, from 10^?15 to 10^?3 S/cm. The results of rheology and dielectric studies indicate that a percolation network is formed that is responsible for the observed changes.     

Multiwalled carbon nanotubes decorated with nitrogen, palladium co-doped TiO2 (MWCNT/N, Pd co-doped TiO2) for visible light photocatalytic degradation of Eosin Yellow in water

Multiwalled carbon nanotube (MWCNT/N), Pd co-doped TiO₂ nanocomposites were prepared by calcining the hydrolysis products of the reaction of titanium isopropoxide, Ti(OC₃H₇)₄ containing multiwalled carbon nanotubes with aqueous ammonia. The prepared samples were characterised by Fourier transform infrared spectroscopy, Raman spectroscopy, thermogravimetric analysis, diffuse reflectance UV?CVis spectrophotometry (DRUV?CVis), XRD, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). DRUV?CVis analysis confirmed the red shift in the absorption edge at lower MWCNT percentages. SEM and TEM images showed the complete coverage of the MWCNTs with clusters of anatase TiO₂ at low MWCNT percentages. Higher MWCNT levels led to their aggregation and consequently poor coverage by N, Pd co-doped TiO₂. The photocatalytic activities of the nanocomposites were monitored by photodegradation of Eosin Yellow under simulated solar and visible light irradiation (???>?450?nm). Irradiation with simulated solar radiation gave higher dye-degradation rates compared to visible radiation. The optimum MWCNT weight percentage in the composites was found to be 0.5. High degradation-rate constants of 3.42?×?10^?2 and 5.18?×?10^?3?min^?1 were realised for the 0.5% MWCNT/N, Pd co-doped TiO₂ composite, using simulated solar light and visible light, respectively.     

Effect on ion dissociation in MWCNT-based polymer nanocomposite

Polymer nanocomposite has been proven to improve the property of polymer salt complex. Organo-modified clay and inorganic oxides are the most commonly used filler for polymer nanocomposite (PNC). However, single wall carbon nanotube (SWCNT)/multiwall carbon nanotube (MWCNT) are becoming popular filler for PNC for their high surface area and high mechanical stability. In this work, a series of PNC sample has been prepared by using polyethylene oxide (PEO)-polydimethylsiloxane (PDMS) blend as polymer matrix, an optimized salt stoichiometry of Ö/Li ~15, and surface-modified MWCNT as filler. The effect of ion-polymer and ion-MWCNT interaction in the polymer nanocomposite has been investigated by using XRD, SEM, FTIR, and electrical study. X-ray diffraction pattern confirms the dispersion of MWCNT inside the polymer chain and modifies the structural parameter of the polymer matrix. FTIR spectra indicate inclusion of MWCNT inside the polymer salt complex which changes the ion dissociation/association in the polymer host matrix. Further, the changes in structural, thermal, and electrical property of the polymer salt complex system have been studied by using SEM, DSC, and impedance analysis. Dc conductivity study shows that optimized PNC sample has conductivity of 8.04 × 10⁻⁵ S cm⁻¹. This is almost two order enhancement from pure polymer salt system (10⁻⁶ S cm⁻¹).