Search

To dates, the facile synthesis of inorganic–coated organic polymer composite has received greater attention in the order of research fields including advanced materials and electrochemical analysis owing to the complementary or synergistic effects. In this context, Pr2O3 and Pr2O3 coated polystyrene (Pr2O3/PS) inorganic–organic colloidal composite were prepared via ultrasound-induced radicals initiated precipitation and dispersion polymerization methods. The synthesized Pr2O3/PS composite was systematically studied by FE-SEM, TEM, EDX, FT-IR, XRD, and XPS analysis. This composite modified glassy carbon electrode (Pr2O3/PS GCE) was utilized to construct a novel electrochemical sensor for the detection assay of chemotherapy agent methotrexate (MTA). Under optimal condition, the designed sensor showed outstanding performance for MTA trace level detection over the linear concentration range of 0.01–236 µM with a detection limit of 0.8 nM for MTA. Furthermore, the prepared sensor accomplished excellent stability and relevant reproducibility, in addition to reliable practical assay in real human blood serum and urine samples. Besides, the possible MTA sensing mechanism of Pr2O3/PS GCE has been deliberated in detail. Our finding suggested that the developed Pr2O3/PS composite might be a favorable material for the fabrication of the high-performance electrochemical sensor.

Herein, we are reporting carboxylic acid-functionalized multi-walled carbon nanotubes-polyindole/Ti2O3 hybrid nanocomposite (f-MWCNTs-PIN/Ti2O3) synthesis, phase structure and morphology studies with extended applications. FE-SEM, and TGA results shows that the hybrid nanocomposite having good thermal stability. This hybrid nanocomposite is utilized to prepare a photo-anode of dye-sensitized solar cells (DSSCs). Interestingly, the doped with TiO2 (f-MWCNTs-PIN/Ti2O3/TiO2) hybrid nanocomposite based photo-anode for DSSC reported power conversion efficiency (PCE) of 8.6% and it is about 6% higher than that of un-doped TiO2 photo-anode. The corresponding short-circuit photocurrent density (Jsc) of 18.30 mA cm−2, open circuit voltage (Voc) of 0.71 V, fill factor (FF) of 0.66, and dye absorption amount is 0.16 × 10−6 mol cm−2 respectively. The obtained results suggest that the hybrid nanocomposite is a suitable photo-anodic material for DSSCs applications.

We applied the nitrogen-doped graphene@nickel oxide (NGE/NiO) nanocomposite doped TiO2 as a photo-anode for dye-sensitized solar cells (DSSCs) on fluorine-doped tin oxide (FTO) substrates by screen printing method. Power conversion efficiency (PCE) of 9.75% was achieved for this DSSCs device, which is greater than that of DSSCs devices using GO/TiO2, and NiO/TiO2 based photo-anodes (PCE=8.55, and 9.11%). Also, the fill factor (FF) of the DSSCs devices using the NGE/NiO/TiO2 nanocomposite photo-anode was better than that of other photo-anodes. The NGE/NiO/TiO2 short-circuit photocurrent density (Jsc) of 19.04mAcm-2, open circuit voltage (Voc) of 0.76V, fill factor (FF) of 0.67 and dye absorption rate 0.21×10-6molcm-2. The obtained results suggest that as-prepared NGE/NiO/TiO2 nanocomposite is suitable photo-anode for DSSCs application.

The controlled morphological TiO 2 particles have gained great importance in a wide variety of applications due to their promising physico-chemical properties. In this study, TiO 2 microstructures with various shapes to utilize as scattering layer in dye-sensitized solar cell (DSSC) applications were successfully synthesized via different hydrothermal conditions. The effects of the versatile preparation parameters including the amount of titania precursor and surfactant, the addition of ethanol/water, and the hydrothermal process temperature and time on the TiO 2 morphology were investigated. The structural and morphological analysis clearly shown that the preparation conditions played crucial roles in the morphology, particle size, and crystalline phase of the TiO 2 microparticles. Different kinds of shapes such as rice- (∼1.10 μm (l) and ∼0.41 μm (w)), star- (∼3.60 μm) and flower-like (3.75 μm) TiO 2 morphological structures were obtained. The morphology and size of the TiO 2 particles were mainly governed by the concentrations of titanium tetraisopropoxide (TTIP) precursor, amounts of tetramethylammonium hydroxide (TMAH) surfactant and hydrothermal temperatures and durations. The as-prepared rice-shaped TiO 2 was composed of mixed anatase and brookite binary phases, whereas the star- and flower-shaped TiO 2 microstructures were consisted of ternary anatase, rutile, and brookite crystalline TiO 2 phases. The three different rice-, star-, and flower-shaped TiO 2 microstructures were employed as scattering layers for photoanodes in DSSCs. Among them, the star-like TiO 2 photoanode based DSSC exhibited the highest power conversion efficiency of 9.56%, which was also better than those of the devices fabricated without scattering layer (a-TiO 2 , 8.38%) and with commercial P25 as scattering layer (a-TiO 2 /P25-TiO 2 , 8.52%) at the same film thickness of ∼14 μm.

Bifunctional electrocatalysts to enable efficient oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) are essential for fabricating high performance metal–air batteries and fuel cells. Here, a defect rich nitrogen and sulfur co-doped graphene/iron carbide (NS-GR/Fe3C) nanocomposite as an electrocatalyst for ORR and OER is demonstrated. An ink of NS-GR/Fe3C is developed by homogeneously dispersing the catalyst in a Nafion containing solvent mixture using an ultrasonication bath (Model-DC150H; power − 150 W; frequency − 40 kHz). The ultrasonically prepared ink is used for preparing the electrode for electrochemical studies. In the case of ORR, the positive half-wave potential displayed by NS-GR/Fe3C is 0.859 V (vs. RHE) and for the OER, onset potential is 1.489 V (vs. RHE) with enhanced current density. The optimized NS–GR/Fe3C electrode exhibited excellent ORR/OER bifunctional activities, high methanol tolerance and excellent long-term cycling stability in an alkaline medium. The observed onset potential for NS–GR/Fe3C electrocatalyst is comparable with the commercial noble metal catalyst, thereby revealing one of the best low-cost alternative air–cathode catalysts for the energy conversion and storage application.