Au nanoparticles decorated graphitic carbon nitride nanosheets as a sensitive and selective fluorescence probe for Fe3+ and dichromate ions in aqueous medium.

Graphitic carbon nitride mutated with metal nanoparticles has captivated great interest as an effective fluorescent sensor for the detection of harmful ions present in water. In the present work, bulk-gCN was synthesized using melamine as precursor, and further Au-gCN nanocomposite were fabricated via in-situ direct reduction deposition method. The structural, morphological, compositional, stability and optical properties of bulk gCN and Au-gCN nanocomposite were examined using various scattering and spectroscopic techniques such as HRTEM, XPS, XRD and SEM. The synthesized bulk gCN straggles during selectivity studies with different cations and anions because of its uneven surface morphology, however in Au-gCN gold nanoparticles are uniformly distributed on the gCN sheets which results in its enhanced selectivity over bulk gCN. This leads to the fabrication of an optical sensor for Fe3+ and Cr2 ions with limit of detection of 4.62 and 2.77 µM, respectively. The sensing of Fe3+ ions corresponds to the photoinduced electron transfer (PET) mechanism, while the detection of chromate species is associated with an inner filter effect (IFE). The practical applicability of the sensor was also evaluated for different environmental water samples. The high stability, sensitivity, and specificity of Au-gCN nanocomposite make it a potential fluorescent probe for Fe3+ and Cr2 ions in water samples.

Preserving plum perfection: Buckwheat starch edible coating with xanthan gum and lemongrass essential oil.

The research focused on the fabrication of composite coatings using buckwheat starch (BS) and xanthan gum (XG) with incorporation of lemongrass (Cymbopogon citratus) essential oil (LEO) with varying concentration (0.75 %, 1.0 % and 1.25 % (w/v). BS was extracted from buckwheat groats (Fagopyrum esculentum) and its physico-chemical characteristics were determined. BS showed spherical and polygonal morphology and its XRD pattern was similar to starch extracted from other cereal sources. The amount of reducing sugar, starch and amylose content in extracted BS were 0.99 ± 0.33 %, 86.32 ± 0.22 % and 21.02 ± 1.89 % respectively, which indicates that BS is a suitable base material for the formation of edible coatings. XG was mixed with BS in different ratios (1:1, 2:1, 3:1 and 4:1) to optimize the best ratio of combination for composite coatings. The coating with a ratio of 2:1 was very smooth and was chosen for incorporation of LEO and the coatings physical, functional, mechanical, thermal and micro-structural characteristics were examined. The coating S5 with 1.25 % (w/v) concentration of LEO showed the best results with least moisture content (MC), minimum water vapor permeability (WVP) and maximum contact angle value. Moreover, the S5 formulation had the highest antioxidant (73.3 %) ability and maximum antimicrobial efficiency with inhibition zones of 22.09 ± 0.06 mm and 28.65 ± 0.14 mm against S. aureus and E. coli respectively. The coatings were then coated on plum fruit, and various parameters like weight loss, pH, shrinkage and TSS were calculated every 4th day during the 20 days of refrigeration period. The coated plums' ripening pace was delayed by the S5 formulation which improved moisture retention, maintained the plums' TSS value and overall pH. Therefore, composite coatings made up of BS, XG and 1.25 % (w/v) can be used as a cost-effective bio-active coating material for plum preservation under refrigeration conditions.

Cobalt-based co-ordination complex-derived nanostructure for efficient oxygen evolution reaction in acidic and alkaline medium.

Electrochemical water splitting is one of the most important method for energy conversion and storage. For this, the design and development of a low-cost robust electrocatalyst are highly desirable. In this study, Cobalt-based electrocatalyst for Oxygen Evolution Reaction was synthesized by thermal treatment of Cobalt-dehydroacetic acid (Co-DHA). The as-synthesized Co nanostructures and Co-DHA crystals were characterized with powder X-ray diffraction, X-ray photoelectron spectroscopy thermo-gravimetric analysis, and field emission scanning electron microscopy. The electrochemical O2 evolution study shows the overpotential (at 10 mV/cm-2) correspond to 294 mV vs reference hydrogen electrode (RHE) for K-300 (Co3O4@300), whereas K-500 (Co3O4@500) shows 170 mV vs RHE values in 1 M KOH solution, respectively. Similar trends have been observed for electrochemical O2 evolution studies in 0.5 M H2SO4, where K-300 and K-500 shows the overpotential (at 10mV/cm-2) of 234 mV vs RHE, and 199 mV vs RHE, respectively. The outcomes show better catalytic efficiency of K-500 as compared to K-300.

Highly Efficient Mesoporous Carbonaceous CeO2 Catalyst for Dephosphorylation.

Phosphorus is fast becoming a critical element, as the global supply and demand are reaching unsustainable levels. Herein, the synthesis, characterization, and applicability of a novel biomass-derived mesoporous carbonaceous material decorated with CeO2 (CeO2-S400) as an efficient catalyst for the dephosphorylation of 4-nitrophenyl phosphate disodium salt hexahydrate are reported. The presence and distribution of CeO2 are evidenced by inductively coupled plasma mass spectrometry (ICP-MS) (118.7 mg/g), high-resolution transmission electron microscopy (HRTEM), and energy dispersive X-ray (EDX) mapping. The apparent rate constant for the efficient catalysis of 4-nitrophenyl phosphate disodium salt hexahydrate was 0.097 ± 0.01 for CeO2-ES and 0.15 ± 0.03 min-1 for CeO2-S400, which followed first-order kinetics. Rate constants normalized by the catalytic loading (k m) were 80.84 and 15.00 g-1 min-1 for CeO2-ES and CeO2-S400, respectively, and the normalized rate constants with respect to surface area were 3.38 and 0.04 m-2 min-1 for CeO2-ES and CeO2-S400, respectively. This indicates that the presence of CeO2 nanoparticles has a catalytic effect on the dephosphorylation reaction.

Attitudes and empathy of youth towards physically disabled persons.

The present study aimed to investigate the attitude and empathy of youth towards physically disabled persons. This study followed a quantitative paradigm. The sample comprised of 100 participants (Male = 50; Female = 50) who were under the age range of 18-25 years. Purposive sampling was taken to gather the data. Attitudes Towards Disabled Persons (ATDP) Scale and the Toronto Empathy Questionnaire were administered on the participants. All the responses were entered on the SPSS software which was analysed through descriptive statistics, t-test, and Pearson's correlation. Findings of this study showed that both males and females had negative attitude towards physically disabled person. Furthermore, males and females were equally empathetic towards physically disabled person. Consequently, there were no gender differences in the attitude and empathy of youth towards physically disabled persons. Also, significant and positive correlation was seen between the two constructs, i.e., attitude and empathy. These results indicated a need of destigmatization about disability especially physical disability in the society.