Graphene TiO2 Research Articles

Tribological properties of Ni–W–TiO2–GO composites produced by ultrasonically–assisted pulse electro co–deposition

The Ni–W–TiO2–Graphene oxide co–deposition with excellent mechanical properties, high wear resistance was produced using ultrasonic–assisted pulse electrodeposition. In the present study, the effects of concentration of graphene oxide and TiO2 particle on the morphology, microstrain, crystallite size, hardness, elastic modulus, and tribological properties of the NiW co–deposition were studied. The morphology, microstructure, and phase analysis of the coatings were investigated using X–ray diffractometer (XRD) and Field Emission Scanning Electron Microscopy (FESEM). X–ray diffraction (XRD) analyses showed that the crystallite size of the Ni(W) matrix decreased with incorporated graphene oxide and TiO2 particles while increased microstrain. Raman analysis is used to confirm the existence of graphene oxide and ceramic particles in the Ni(W) matrix. FESEM results indicated that the Ni–W–TiO2–Graphene oxide co–deposition displayed a compact surface structure, while the crystallite size and microstrain of the composite coating were 7 nm and 3.5 × 10−3, respectively. Nano–mechanical test results showed a maximum of 8.1 GPa and ~209 GPa increases in hardness and elastic modulus with adding graphene oxide and TiO2, respectively. Incorporation of graphene oxide and TiO2 particles into the matrix, the wear rate of the resulting coating can be increased significantly. The tribological behavior of the Ni–W–GO composite coating deposited various graphene oxide concentrations and NiW, Ni–W–TiO2, the Ni–W–TiO2–Graphene oxide coating was compared, and their different wear mechanisms have been discussed. Detailed studies of the worn surface were performed with SEM, EDS, and Raman.

Enhanced efficiency of polyamide membranes by incorporating TiO2-Graphene oxide for water purification

Membrane-based separation processes are very effective in several applications such as purification of drinking water and treatment of wastewater. Polymer-inorganic composite reverse osmosis membrane is a powerful method that opens the door to merge different properties of inorganic materials like mechanical and thermal stability with organic polymer properties including processability and flexibility. This work aims to modify aromatic polyamide membrane surfaces by the simultaneous incorporation of graphene oxide (GO) and TiO2 composite, to enhance the salt rejection and filtration performance of the membrane. 1, 3, 5-benzenetricarbonyl chloride, TiO2-GO composite, and m-phenylenediamine were polymerized on the surface of porous polysulfone support. Fourier Transform infra-red spectroscopy, X-ray photoelectron spectroscopy, and X-ray diffraction were applied to confirm the presence of TiO2-GO composite on the membrane surface. Scanning electron microscopy equipped with energy-dispersive X-ray and atomic force microscopy were carried out to analyze the surface morphology and reveal the smoothening of the modified membrane surface. Water contact angle measurements were carried out to visualize the hydrophilicity improvements of modified membranes. The performance parameters of the membrane, including permeate flux, salt rejection, and oil rejection were evaluated using a laboratory setup. The incorporation of TiO2-GO composite into the membrane matrix enhanced the membrane performance with 62 LMH (Lm−2h−1) permeate flux, 97% salt rejection, and 100% hydrocarbons rejection, due to changes in charge, roughness, and hydrophilicity of the membrane surface.

Aminosilicate modified mesoporous anatase TiO2@graphene oxide nanocomposite for dye-sensitized solar cells

Highly ordered aminosilicate modified mesoporous anatase TiO2 graphene oxide (mTiO2@GO/NH2) nanocomposite microspheres are prepared by hydrothermal method and are investigated using various spectral and microscopic techniques. X-ray photoelectron spectroscopy and Fourier-transform infrared spectral analyses confirmed the presence of NH2 groups in the mTiO2@GO/NH2 nanocomposites. The mTiO2@GO/NH2 exhibits lower photoluminescence intensity than bare mesoporous TiO2 microspheres, disclosing an efficient photoelectron transfer from the mesoporous TiO2 to GO through aminosilicate chain. Atomic force microscopic analysis reveals that mTiO2@GO/NH2 thin film has highly ordered porous structure. The highly porous mTiO2@GO/NH2 exhibits good dye loading for light harvesting and allow good electrolyte contact, which minimizes the back-electron transfer between photoanode and oxidized dye molecules. The dye-sensitized solar cell (DSSC) based on mTiO2@GO/NH2 nanocomposite photoanode, with optimum amount of (3-aminopropyl)triethoxysilane (APTES), delivers an overall photo-conversion efficiency of 5.11%, which is 2.5-fold higher than that of the DSSC based on pure mesoporous TiO2 microspheres (mTiO2 MS) photoanode. The significant photovoltaic performance of the present DSSC based on mTiO2@GO/NH2 photoanode is due to synergistic effects between the TiO2 and GO heterojunction.

A highly sensitive and selective molecularly imprinted electrochemical sensor modified with TiO2-reduced graphene oxide nanocomposite for determination of podophyllotoxin in real samples

To obtain an electrochemical sensor with high sensitivity and good selectivity for determination of podophyllotoxin (PPT), a kind of graphene composite ([email protected]2) with multi-layer structure and excellent conductivity was prepared by hydrothermal treatment of reduced graphene oxide (rGO) and TiO2 nanoparticles. The composite was characterized by transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), and a sensor using [email protected]2 as a signal amplification element was fabricated by in-situ polymerization of PPT imprinted membrane (PPT-MIM) on the [email protected]2 modified glassy carbon electrode (PPT-MIM/[email protected]2/GCE). The structure and electrochemical performance of PPT-MIM/[email protected]2/GCE as well as the mechanism with superior conductivity of [email protected]2 exceeding the ones of the mixture of TiO2 and rGO (TiO2-rGO) or the pure TiO2 and rGO were explained with different technologies. Under the optimal conditions, the present sensor showed a linear response for the determination of PPT by differential pulse voltammetry (DPV) in the range of 1.0 × 10−9 − 1.0 × 10−7 mol L−1 (R2 = 0.9980) and 1.0 × 10−7 − 3.0 × 10−4 mol L−1 (R2 = 0.9991) with the limit of quantification is 1.0 × 10−9 mol L−1 and the limit of detection of 3.0 × 10−10 mol L−1. The sensor not only possesses high sensitivity and good selectivity, but also exhibits excellent repeatability and stability. It has been used to detect PPT in real samples (including Podophyllum hexandrum, human urine and human whole blood) with satisfied recoveries of 92.0%–102.3%.

UV Light-Modulated Fluctuation-Enhanced Gas Sensing by Layers of Graphene Flakes/TiO2 Nanoparticles

We present experimental results of fluctuation-enhanced gas sensing by low-cost resistive sensors made of a mixture of graphene flakes and TiO2 nanoparticles. Both components are photocatalytic and activated by UV light. Two UV LEDs of different wavelengths (362 and 394 nm) were applied to modulate the gas sensing of the layers. Resistance noise was recorded at low frequencies, between 8 Hz and 10 kHz. The sensors’ response was observed in an ambient atmosphere of synthetic air and toxic NO2 at selected concentrations (5, 10, and 15 ppm). We observed that flicker noise changed its frequency dependence at different UV light wavelengths, thereby providing additional information about the ambient atmosphere. The power spectral density changed by a few times as a result of UV light irradiation. The sensors were operated at 60 and 120°C, and the effect of UV light on gas sensing was most apparent at low operating temperature. We conclude that UV light activates the gas-sensing layer and improves gas detection at low concentrations of NO2. This result is desirable for the detection of the components of gas mixtures, and the modulated sensor can replace an array of independent resistive sensors which would consume much more energy for heating. We also suggest that a more advanced technology for preparing the gas-sensing layer, by use of spin coating, will produce corresponding layers with thickness of about a few μm, which is about ten times less than that for the tested samples. The effects induced by the applied UV light, having a penetration depth of only a few μm, would then be amplified.

Photo-generation of mercury cold vapor mediated by graphene quantum dots/TiO2 nanocomposite: On line time-resolved speciation at ultra-trace levels

Mercury speciation was achieved using a nanocomposite, consisting of graphene quantum dots (GQDs) and TiO2 nanoparticles, to mediate photo-degradation of mercurial species into the Hg cold vapor detected by atomic spectrometry. Sample solution (containing Hg2+, CH3CH2Hg, and CH3Hg at hundreds of ng L−1) was placed in quartz tube containing formic acid solution (2% v/v) and microliter aliquot of GQDs/TiO2 nanocomposite dispersion (0.6 mg of nanocomposite). The tube was placed inside a photochemical reactor then, adapted to the mercury-dedicated spectrometer. Quantitative speciation was achieved taking advantage of the differences in UV photodegradation kinetics: Hg2+ (5 min), CH3CH2Hg (9 min) and CH3Hg (13 min). Gas-chromatography cold vapor atomic fluorescence spectrometry was used to confirm the evolution of the reactions over time during photo-reaction. The limits of detection were 10 ng L−1 for CH3CH2Hg and 7 ng L−1 for Hg2+ and CH3Hg.

Hybrid 1D/2D Carbon Nanostructure-Incorporated Titania Photoanodes for Perovskite Solar Cells

The incorporation of carbon nanotubes (CNTs) and graphene, two amazing carbon nanostructures, in photovoltaics has drawn a lot of attention, especially as TiO2–CNT or TiO2–graphene nanocomposite photoanodes. In this study, we prepare a hybrid TiO2–CNT–graphene mesoporous thin film through a mixed-solvent and in situ hydrothermal synthesis, as well as an engineered two-step calcination process, and employ it as a photoanode in perovskite solar cells. The best-performance device (with 0.5 wt % (CNT + graphene)) shows a short-circuit current density of 24.8 mA cm–2, which is 43.4, 39.3, and 19.2% higher than that of bare TiO2-, TiO2–CNT-, and TiO2–graphene-based cells, respectively. Owing to the combination of high electron extraction ability of CNTs and enormously high specific surface area of graphene sheets confirmed by photoluminescence spectroscopy and photovoltage decay measurements, superior charge transport is provided in the photoanode system, resulting in this enhanced photovoltaic performance, with a power conversion efficiency of up to 13.97%. This work demonstrates that the simultaneous presence of graphene and CNT, instead of employing them individually, in a nanocomposite system with TiO2 is able to bring the field of charge collection studies in PSCs up to the mark.

Functionalized Graphene Derivatives and TiO2 for High Visible Light Photodegradation of Azo Dyes.

Functionalized graphene derivatives including graphene oxide (GO), reduced graphene oxide (rGO), and heteroatom (nitrogen/sulphur (N/S) or boron (B))-doped graphene were used to synthesize composites with TiO2 (T). The photocatalytic performance of composites was assessed for the degradation of Orange G dye (OG) under simulated solar light. All the prepared graphene derivatives—TiO2 composites showed better photocatalytic performance than bare TiO2. A higher photocatalytic activity was found for the composites containing GO and N/S co-doped rGO (kapp = 109.2 × 10−3 and 48.4 × 10−3 min−1, for GO-T and rGONS-T, respectively). The influence of both initial solution pH and the reactive species involved in the OG degradation pathway were studied. The photocatalytic activity of the samples decreased with the increase of the initial pH (from 3.0 to 10.0) due to the occurrence of electrostatic repulsive forces between the photocatalysts surface and the molecules of OG, both negatively charged. The use of selective scavengers showed that although the photogenerated holes dominate the degradation mechanism, radicals and singlet oxygen also participate in the OG degradation pathway. In addition, reutilization experiments indicated that the samples were stable under the reaction conditions used.

Laser synthesis of TiO2–carbon nanomaterial layers with enhanced photodegradation efficiency towards antibiotics and dyes

Graphene-based photocatalytic layers were prepared by reactive matrix assisted pulsed laser evaporation technique. Binary, nitrogen doped reduced graphene oxide (RGO)/TiO2 and ternary RGO/TiO2/graphitic carbon nitride (g-C3N4) compounds were synthesized and simultaneously deposited onto solid substrates. Aqueous dispersions of commercial graphene oxide platelets and TiO2 nanoparticles were prepared. NH3 or melamine powder was added to the dispersions to achieve enhanced nitrogen doping and synthesis of g-C3N4 during laser irradiation. The photocatalytic efficiency of the layers towards degradation of antibiotic, chloramphenicol and organic dye molecules was systematically investigated and correlated with structural, compositional, and morphological features. This study provides new insights into the importance of TiO2 crystal facets and the synergistic effects between TiO2 nanocrystals and the other constituents, nitrogen doped RGO and g-C3N4 of the hybrid layers. As a result of combined effect of constituent materials, TiO2, RGO, and g-C3N4 as well as N doping of RGO, through the generation of quaternary and pyrrolic N functionalities, the composite layers showed high photocatalytic efficiency for degradation of organic molecules. Stability and reusability experiments indicated that the composite layers maintain their high photodegradation efficiency towards organic molecules during consecutive degradation cycles. Active radical scavenging experiments were also carried out in order to determine the role of the main active species involved in the photocatalytic degradation process.

Investigation on photo-induced mechanistic activity of GO/TiO2 hybrid nanocomposite against wound pathogens

Pathogenic microorganism delays wound-healing process by causing infection. In recent years, researchers have developed various kinds of photo-active nanomaterials with enhanced antibacterial properties. This work focus on the preparation of graphene oxide and TiO2 nanocomposites (GO/TiO2) as a visible light-induced high efficiency antibacterial material. The hydrothermal method was used for the synthesis of GO/TiO2 nanocomposites at 180 oC for 3 h with different loading percentages of GO (10, 20, 30, 40 and 50 wt. %). The systematic characterization tools including X-ray diffraction analysis, FT-IR, UV-vis, Raman and TEM which were used to understand the physicochemical properties of the prepared GO/TiO2 nanocomposites. Furthermore, GO/TiO2 nanocomposites were used as photocatalytic active materials against wound infection-causing bacteria in the presence of visible light irradiation. The possible antibacterial mechanism under presence and absence of light were depicted. The antibacterial mechanism of the GO/TiO2 nanocomposite was investigated on wound infection-causing bacteria such as Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Enterococcus faecalis. The high hemocompatibility and the cellular biocompatibility of the nanocomposite aids in using it for wound-healing application. Overall, the results suggest that the GO/TiO2 nanocomposite could be developed as a photo-active nanomaterial against pathogenic microorganisms that are present in wound.

Synthesis of Titanium Dioxide (TiO2)/Reduced Graphene Oxide (rGO) thin film composite by spray pyrolysis technique and its physical properties

TiO2/reduced graphene oxide (rGO) thin films prepared from different GO concentrations (0, 3, 5, and 10 wt%) were successfully deposited on fluorine-doped tin oxide (FTO) glass substrates using spray pyrolysis technique (SPT). The structural, morphological and optical properties of the thin films were examined using Raman spectroscopy and X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and UV–Vis spectroscopy, respectively. The presence of rGO in the thin films structure was confirmed by Raman analysis with D and G band intensity ratios (ID/IG) of 1.01, 1.03 and 1.08 for GO concentrations of 3, 5, and 10 wt%, respectively. The characteristic XRD peaks for TiO2 and rGO at 2ϴ values of 25.3° and 22-23°, respectively, indicate the bonding of TiO2 with rGO. Surface morphology analysis of the TiO2/rGO thin films reveal homogenous distribution of graphene nanosheets and TiO2 on FTO glass substrate. In addition, optical transmittance reduced from 80% for TiO2 to 45% for TiO2/rGO prepared with 10 wt% GO. From UV–Vis analysis, band gap energy for TiO2, and TiO2/rGO reduced from 3.63 eV to 3.38 eV, with increase in the concentration (wt.%) of GO in the thin films. Thus, the use of the SPT method is believed to provide a cost-effective and easy approach to synthesize good quality TiO2/rGO thin film on FTO glass for photodetector and solar cell applications.

TiO2 Nanoparticles Decorated Graphene Nanoribbons for Voltammetric Determination of an Anti-HIV Drug Nevirapine

In the present study, electrochemical behavior of nevirapine on a glassy carbon electrode (GCE) modified with TiO2 nanoparticles decorated graphene nanoribbons was investigated. Characterization of different components used for modifications was achieved using Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). The electrochemical behavior of nevirapine on the modified electrodes was examined using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), chronoamperometry (CA), and differential pulse voltammetry (DPV). A considerable oxidation potential decrease of +352 mV for nevirapine in 0.1 M phosphate-buffered saline (PBS), pH 11.0, was achieved due to synergy offered by graphene nanoribbons and TiO2 compared to graphene nanoribbons (+252 mV) and TiO2 (−37 mV), all with respect to the glassy carbon electrode. Under optimized conditions, DPV gave linear calibrations over the range of 0.020–0.14 µM. The detection limit was calculated as 0.043 µM. The developed sensor was used for determination of nevirapine in a pharmaceutical formulation successfully.

Influence of N doping and the functional groups of graphene on a RGO/TiO2 composite photocatalyst

Reduced graphene oxide (RGO) assisted TiO2 composite photocatalysts have attracted increased attention because of their high photocatalytic performance under both UV- and visible-light irradiation. However, the corresponding properties under the long wavelength irradiation is far from expected. In this study, a series of RGO samples with well-designed N impurity and optimized surface functional groups are prepared and employed during hybridization with TiO2 (named N-RGO/TiO2). The coupling between the doped N atoms and surface functional groups is analyzed based on the resulting photocatalytic performances, and the specific mechanism is revealed by the EPR, IR and lifetime of the photoinduced electrons. After comparing the corresponding performances of the RGO/TiO2 and RGO/N-TiO2 specimens, the results show that the surface functional groups of the RGO serve as a precondition to achieve π-d coupling between the graphene basal plane and TiO2 nanoparticles, while N atoms in the RGO enhance the resulting photoactivity under a long wavelength range (>510 nm). The findings provide a potential approach to promote the photocatalytic properties of graphene-based composite photocatalysts with the low-energy incident photons.

Produção de Componentes de Células Fotovoltaicas Sensibilizadas de Baixo Custo de 3ª Geração

As células solares sensibilizadas por corantes apresentam-se como uma nova opção de custo e efiiência em produção de energia limpa. Dessa forma, a utilização de novos sensibilizadores e novos processamentos nos componentes dos eletrodos destas células se faz necessária para uma maior popularização. Assim, neste trabalho, foram estudados materiais como o óxido de grafeno, TiO2 e sensibilizadores a base de antocianinas obtidos por rotas simples e que apresentaram bons resultados. As propriedades estruturais e ópticas indicaram que os pós P25 e TiO2 sensibilizados podem ser aplicados como fotoanodos e o óxido de grafeno como contra-eletrodo nas células fotovoltaicas de baixo custo.

Synergistic Removal of Bromate and Ibuprofen by Graphene Oxide and TiO2 Heterostructure Doped with F: Performance and Mechanism

The batch experiments of photocatalytic oxidation-reduction of bromate and ibuprofen (IBP) by graphene oxide (GO) and TiO2 heterostructure doped with F (FGT) particles were conducted. The performance and mechanism of synergistic removal of bromate and IBP by FGT were discussed. The results show that a demonstrable synergistic effect and excellent removal rate of bromate and IBP by FGT were exhibited. When pH is 5.2 and the dosage of FGT is 0.1 g/L, the reaction rate constants of bromate and IBP increased from 0.0584 min-1 and 0.4188 min-1 to 0.1353 min-1 and 0.4504 min-1, respectively, compared with the degradation of bromate or IBP alone. The reaction of photocatalytic synergistic degradation is appropriately fitted through Langmuir-Hinshelwood first-order kinetics. The mechanism of synergistic removal of bromate and IBP by FGT was discussed. And electrons (e-), hydroxyl radical (⋅OH), and superoxide radical (⋅O2-) are the main active species. The electrons play a main role in the bromate reduction, and bromine is the only reduction product, while the oxidation of IBP is the result of ⋅OH and ⋅O2-, and ⋅OH plays a key role. The recombination of electrons and holes is inhibited by simultaneous consumption of bromate and IBP, which makes full use of the redox properties of FGT and plays a synergistic role in the removal of pollutants. The results indicate that photocatalytic oxidation-reduction by FGT is a promising, efficient, and environmental-friendly method for synchronous removal of combined pollution in water.

Influence of morphology and interfacial interaction of TiO2-Graphene nanocomposites on the visible light photocatalytic performance

In most cases, different morphologies of the same composites correspond to different properties. In this paper, the TiO2/rGO heterostructure system with three morphologies was obtained by one-step hydrothermal method through regulating hydrothermal time. Compared with TiO2 nanoparticle/reduced graphene oxide (TNP/rGO) and TiO2 nanobelt/reduced graphene oxide (TNB/rGO), TiO2 nanotube/reduced graphene oxide (TNT/rGO) showed higher photocatalytic activity (78.5%, 2 ​h) toward degrading Rhodamine B and 2, 4-Dichlorophenol under visible light. The mechanism of enhancing photocatalytic activities of the TiO2/rGO system was confirmed by free radicals trapping experiment, ESR, PL and photocurrent measurement. It is revealed that the hole (h+) is the main reactive specie in TNT/rGO heterojunction and rapid transfer of photogenerated electrons is responsible for enhancing photocatalytic activity. This work not only emphasizes the important role of morphology in improving photocatalytic activity, but also provides a simple strategy to alter the morphology of TiO2.

Modeling and optimization of Photocatalytic Decolorization of binary dye solution using graphite electrode modified with Graphene oxide and TiO2.

In this paper, the experimental design methodology was employed for modeling and optimizing the operational parameters of the photocatalytic degradation of a binary dye solution using a fixed photocatalytic compound. The compound used was modified graphite electrode (GE) with graphene oxide (GO) on which TiO2 nanoparticles were immobilized. GO nanoparticle was deposited on graphite electrode (GO-GE) using electrochemical approach. TiO2 nanoparticles were immobilized on GO-GE by solvent evaporation method. A binary solution containing mixture of methylene blue (MB) and acid red 14 (AR14) was chosen as dye model. The degradation intermediates were detected and analyzed using gas chromatography. Effect of different factors on the photocatalytic decolorization efficiency was investigated and optimized using response surface methodology (RSM). The obtained results indicated that the prepared TiO2-GO-CE can decolorize MB with high efficiency (93.43%) at pH11, dye concentration of 10mg/L and 0.04g of immobilized TiO2 on the GO fabricated plates after 120min of photocatalytic process. It was demonstrated that by modifying GE with GO the stability of the electrode was remarkably enhanced. The ANOVA results (R2 = 0.97 and P value <0.0001 for MB, R2 = 0.96 and P value <0.0001 for AR14) and numerical optimization showed that it is possible to make good prediction on decoloration behavior and save time and energy with less number of experiments using design of experiments (DoE) like the RSM. Graphical abstract Wastewater treatment processWastewater treatment process.

Effect of graphene concentration on tribological properties of graphene aerogel/TiO2 composite through controllable cellular-structure

The microstructure design of the packing is a crucial factor in determining the performances of sealing capacity. Graphene aerogel/TiO2 (GA/TiO2) composites were fabricated by an infiltration method using porous GA as a framework. GA with different pore sizes and morphologies was tuned by changing concentration of graphene. The structural morphology of the graphene layer structure transformed into porous structure as the graphene concentrations increased. In addition, mechanical properties and tribological behaviors of GA/TiO2 composites with different graphene concentrations were comparatively investigated. The results show that the TiO2 particles are more uniformly filled into the GA with higher graphene concentration due to the porous separation effect. Therefore, the GA/TiO2 composites of higher concentrations have a better elongation and mechanical properties. Simultaneously, the tribological behavior is excellent owing to the self-lubricating properties of graphene and tiny TiO2, and the TiO2 cluster can effectively prevent the crack propagation. Moreover, the tribological performance of the GA/TiO2 samples under wet friction conditions is better than that under dry friction conditions due to the self-transport operation of lubricants assisted by the through capillary action, besides the self-lubricating effect of graphene and tiny TiO2 particles.

Simultaneous Detection of 4-Aminophenol and Paracetamol Using a Glassy Carbon Electrode Modified with Graphene Oxide, TiO2 and Gold Nanoparticles

A novel highly sensitive nanoelectrochemical sensor was prepared using graphene oxide/titanium dioxide/gold nanoparticles composites (GT@AuNPs) modified glassy carbon electrode (GCE) to measure paracetamol (PA) and 4-aminophenol (4-AP) simultaneously. It can be found that PA and 4-AP could be completely separated on the GT@AuNPs/GCE using cyclic voltammetry and differential pulse voltammetry technique. Under the best conditions, the linear responses for PA from 0.10 to 300.00 μM with the detection limits of 0.78 nM. And the linear responses for 4-AP from 0.10 to 150.00 μM with the detection limits of 2.36 nM. This sensor can be used to detect acetaminophen in pharmaceutical formulations with satisfactory results, indicating that the electrochemical sensor has potential application value.

Synergistic Effect of Polyethylene Oxide Layer on TiO2/TiO2-Graphene based Perovskite Solar Cell

This article reports the influence of titania (TiO2) and TiO2-graphene (TGr) as electron transport layer (ETL) on the performance of polyethylene oxide (PEO) based perovskite solar cell (PSC). Compared to most commonly used ETLs, graphene based ETLs showed immense promise towards scalable fabrication and higher carrier injection of PSC. Driven by this idea, PEO layer was introduced in TiO2 and TGr based PSC to inspect the feasibility of achieving notably high fill factor. As-grown nanocomposites were analyzed using varied analytical tools to determine the effect of graphene inclusion on their morphology, optical and electrical properties. An increase in the absorption bandwidth and red-shift in the absorption peak was observed from UV-VIS spectra indicating band gap narrowing. By exploiting TGr nanocomposite in perovskite solar cells as electron collection layer, a remarkable fill factor of 44% has been achieved. In short, present disclosure may contribute towards the development of ETL in high performing PEO based perovskite solar cell (PSC).