Platinum substituted Cobalt(II, III) Oxide: Interplay of tetrahedral Co(II) sites towards electrochemical oxygen evolution activity

Substitution of ionic platinum is carried out in Co3O4 host synthesized by solution combustion strategy. These Pt substituted Co3O4 spinels characterized by XRD show pure crystalline phase of Co3O4 without any separated peaks related to Pt/PtOx. Electrochemical OER activities of these spinels are investigated by cyclic voltammetry, linear sweep voltammetry and chronoamperometry in neutral, alkaline and neutral buffer electrolytes. LSV studies on 1% Pt substituted Co3O4 exhibit a low overpotential (¿) of 455 mV at 20 mA cm-2 in KOH, as compared to PBS medium. Tafel slope value of 117 mV dec-1 in KOH represents one electron EC mechanism. The detailed XPS studies indicate that Pt doping increases the tetrahedral Co2+ sites of Co3O4. XPS studies before and after OER also infers that the mixed valence of Co in the host (Co3O4) undergoes redox (Co2+/Co3+) changes with simultaneous reduction in Pt dopant from Pt4+ to Pt2+ influencing the OER activity

Assessment of herbaceous biomass: A study in Rowghat mining areas of Chhattisgarh, India

We studied Rowghat sites of Chhattisgarh, India, with the objective to assess herbaceous layer composition, biomass and to prepare management implications for conservation of ecologically sensitive species in mined areas. Ten sites (Anjrel, Khodgaon, Khadkagaon, Takrel, Rav Dongri, Tarhur, Godenmar Dongri, Parmad Dongri, Bhusujkun Dongri and Bedhiyar Nala) were selected for the study. We randomly placed quadrats of 1x1 m size in each site. A sum of 36 species distributed in 15 families were encountered in Rowghat mining site. The total density of all herbs was highest (724000) in Bhusujkun Dongri followed by Khadkagaon (678000), Rav Dongri (662000) and lowest was recorded from Godenmar Dongri (502000). The density of herbs across the study area ranged from 9,000 (D. ciliaris) to 2,50,000 (S. viridis) in the areas of Tarhur and Bediyar Nala. The herb species were unevenly distributed across mined areas. The Chlorophytum tuberosum and Cassia tora were recorded only from Tarkel and Godenmar Dongri sites, respectively. The total belowground biomass ranged between 0.097 t/ha in Godenmar Dongri to 0.18 t/ha in Rav Dongri. An ecological approach is must to restore the collieries. Protection of ecologically sensitive herbs is necessary. Prolonged ban on mining activity in Rowghat forest area is needed to restore degraded forest

Study on photoinduced charge transfer between Citrus Limon capped CdS quantum dots with natural dyes

The development of highly efficient Quantum dots-based Dye Sensitized Solar Cells (DSSCs) capable of absorbing a broader spectrum of solar light has garnered significant interest. In these systems, the proper selection of sensitizers plays a crucial role. Consequently, the exploration of highly efficient, cost effective and non-toxic sensitizer options has led to a growing focus on natural dyes. In this study, we investigated the credibility of natural dyes Beta Vulgaris, Ixora coccinea and Butea monosperma were explored as potential sensitizer in a Cadmium Sulphide (CdS) quantum dots-based system. Moreover, the effect of Citrus Limon Extract (CLE) as a capping agent through X-ray Photoelectron Spectroscopy (XPS) and Electron Paramagnetic Resonance (EPR) analyses. A Density Functional Theory (DFT) model was also presented to explore the charge accumulation on CdS surface due capping action. Quenching mechanism of CLE-CdS with different dyes under various irradiation conditions was studied and their mechanism were defined. Lastly, our finding demonstrates the effect of H-aggerated dye on CLE-CdS, indicating its potential in increasing solar light absorption