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The growing demand for platinum group metals (PGMs) such as platinum (Pt) and palladium (Pd) necessitates novel approaches for efficient and selective separation and regeneration. Polyhedral oligomeric silsesquioxane (POSS)-based materials offer promising potential for retrieving PGMs from water, especially under raucous conditions. In this study, we present the first-ever development of a novel highly loaded carboxylic acid functionalized sulfur-containing POSS (POSS–S–COOH) through a one-step method. POSS–S–COOH demonstrated exceptional adsorption capabilities, with the highest adsorption capabilities for PtCl62− and PdCl42− measured at 597.2 ± 20.2 mg g−1 and 692.6 ± 25.1 mg g−1, respectively, in highly acidic water media. Remarkably, the adsorbent exhibited high selectivity toward PdCl42− and PtCl62− in the presence of various co-existing and common metal ions, such as Ni(II), Zn(II), Mg(II), Cu(II), Pb(II), Cd(II), Fe(III), and Co(II). Furthermore, it demonstrated proficient recovery capabilities for both PtCl62− and PdCl42− at pH 10, without the need for harsh desorbents such as thiourea, marking a significant achievement in this field. The pseudo-second-order as well as intraparticle diffusion kinetic and Langmuir isotherm data fitting indicated strong interactions resulting from electrostatic, H-bonding, and chelate bonding among the active functional sites of POSS–S–COOH and PtCl62−/PdCl42−. Thermodynamic analyses revealed spontaneous and endothermic adsorption of PtCl62− and PdCl42− by POSS–S–COOH. Density functional theory (DFT) calculations supported these findings, demonstrating high binding energy and low energy gaps, contributing to the proficient adsorption of PtCl62−/PdCl42− by POSS–S–COOH. Furthermore, POSS–S–COOH displayed excellent acid-resistance at pH 1, making it a promising adsorbent for potential industrial applications. This novel approach opens up new avenues for highly selective and easily regenerable POSS–S–COOH for the retrieval of precious metals from highly acidic water media. [ABSTRACT FROM AUTHOR]

A new reduced graphene oxide (rGO) based bi‐phasic crystal of MnO2, namely α‐MnO2 nanorods and δ‐MnO2 nanoflakes containing heterostructured hybrid nanoflower rGO@α‐MnO2/rGO@δ‐MnO2 has been fabricated through a facile hydrothermal method followed by annealing treatment. The successful synthesis of the hybrid material was studied by XRD, Raman, BET, FESEM with EDX, FTIR and TEM analyses. An efficient N‐alkylation reaction of substituted aromatic amines with aromatic alcohols was carried out under solvent‐free aerobic conditions in the presence of catalytic amount of rGO@α‐MnO2/rGO@δ‐MnO2. The catalyst shows excellent activity in terms of high yields (up to 98 %), short reaction time (10 h) along with a simple work‐up process. The spent material can be regenerated several times without causing any serious decrease in catalytic activity. Moreover, cyclic voltammetry (CV), galvanostatic charge‐discharge (GCD), and cyclic stability techniques were executed to evaluate the performances of rGO@α‐MnO2, rGO@δ‐MnO2, and rGO@α‐MnO2/rGO@δ‐MnO2 as energy storage materials. Among all those materials, rGO@α‐MnO2/rGO@δ‐MnO2 exhibited a proficient specific capacitance, CS (267 F/g at 1 A/g) along with excellent cycling ability (∼83 % retention up to 10000 cycles). The superb electrochemical performance of rGO@α‐MnO2/rGO@δ‐MnO2 might be ascribed to the combination of bi‐phasic α‐MnO2 and δ‐MnO2 with rGO sheets, resulting in a flower‐like structure. [ABSTRACT FROM AUTHOR]