Employing Piper longum extract for eco-friendly fabrication of PtPd alloy nanoclusters: advancing electrolytic performance of formic acid and methanol oxidation.

Advancement in bioinspired alloy nanomaterials has a crucial impact on fuel cell applications. Here, we report the synthesis of PtPd alloy nanoclusters via the hydrothermal method using Piper longum extract, representing a novel and environmentally friendly approach. Physicochemical characteristics of the synthesized nanoclusters were investigated using various instrumentation techniques, including X-ray photoelectron spectroscopy, X-ray diffraction, and High-Resolution Transmission electron microscopy. The electrocatalytic activity of the biogenic PtPd nanoclusters towards the oxidation of formic acid and methanol was evaluated chronoamperometry and cyclic voltammetry studies. The surface area of the electrocatalyst was determined to be 36.6 m2g-1 by Electrochemical Surface Area (ECSA) analysis. The biologically inspired PtPd alloy nanoclusters exhibited significantly higher electrocatalytic activity compared to commercial Pt/C, with specific current responses of 0.24 mA cm - 2 and 0.17 mA cm - 2 at synthesis temperatures of 180 °C and 200 °C, respectively, representing approximately four times higher oxidation current after 120 min. This innovative synthesis approach offers a promising pathway for the development of PtPd alloy nanoclusters with enhanced electrocatalytic activity, thereby advancing fuel cell technology towards a sustainable energy solution.

Microwave-assisted green synthesis of multi-functional carbon quantum dots as efficient fluorescence sensor for ultra-trace level monitoring of ammonia in environmental water.

This study reports a facile green preparation of self-assembled multi-functional carbon quantum dots (CQDs) via direct pyrolysis technique coupled with microwave-assisted synthesis using Ziziphus Mauritiana stone biomass (as a bio-resource precursor). The synthesized multi-functional CQDs was characterized using FT-IR, XRD, XPS, TEM, and fluorescence spectroscopy techniques. The results exhibit that the prepared CQDs are spherical-shaped with an average diameter of 2-4 nm and showed bright bluish-green emissions property with stable dispersion and high photostability in the aqueous medium. Furthermore, the emission properties of CQDs were examined by quenched with ammonia (NH3) and other molecules in aqueous media. Results indicated that the developed CQDs showed effective fluorescent for the selective and sensitive detection (sensor) of NH3 with a detection limit of 10 nM. Thus, the presented procedure is a simple, low-cost, efficient, chemical-free synthesis of CQDs and can be applied as selective and sensitive (sensor) monitoring of NH3 concentration in aquatic environmental samples.

Novel pure α-, ß-, and mixed-phase α/ß-Bi2O3 photocatalysts for enhanced organic dye degradation under both visible light and solar irradiation.

Combining the pure α- and ß-phases of bismuth oxide enhances its photocatalytic activity under both visible and solar irradiation. α-Bi2O3, ß-Bi2O3, and α/ß-Bi2O3 were synthesized by a solvothermal calcination method. The structural, optical, and morphological properties of the as-synthesized catalysts were analyzed using XRD, UV-DRS, XPS, SEM, TEM, and PL. The bandgaps of α/ß-Bi2O3, α-Bi2O3, and ß-Bi2O3 were calculated to be 2.59, 2.73, and 2.34 eV, respectively. The photocatalytic activities of the catalysts under visible and solar irradiation were examined by the degradation of carcinogenic reactive blue 198 and reactive black 5 dyes. The kinetic plots of the degradation reactions followed pseudo-first-order kinetics. α/ß-Bi2O3 exhibited higher photocatalytic activity (∼99%) than α-Bi2O3 and ß-Bi2O3 under visible and solar irradiation. The TOC and COD results confirmed the maximum degradation ability of α/ß-Bi2O3, and the decolorization percentage remained above 90%, even after five cycles under visible irradiation. The photocatalytic dye degradation mechanism employed by α/ß-Bi2O3 was proposed based on active species trapping experiments.

Facile Synthesis, Characterization and Enhanced Photocatalytic Activities of NiWO4/Nitrogen Doped Reduced Graphene Oxide Nanocomposites.

In this study, we report the synthesis of NiWO4/nitrogen doped reduced graphene oxide nano composite by one-pot hydrothermal method. The NiWO4 nano particles were dispersed uniformly on graphene sheets. The as prepared NiWO4, NiWO4/5% rGO and NiWO4/N-5% rGO composites were analytically characterized by Powder X-ray diffraction (XRD), Raman spectroscopy, Diffuse reflectance spectroscopy (DRS-UV), Scanning electron microscopy (SEM) and N2 adsorption-desorption isotherm. The photocatalytic performances of the synthesized composites were evaluated towards the photo degradation of congo red (CR) under visible light radiation. The synthesized catalysts showed remarkable photocatalytic activity in the degradation of CR. Among the catalysts NiWO4/N-5% rGO showed the highest decolourization of congo red (92%) under visible light irradiation. This high activity is attributed to its high e- transport property. Our results provide an invaluable methodology for designing high-performance photo-catalysts for new energy applications.