RESUMO
Flat panel reactors, coated with photocatalytic materials, offer a sustainable approach for the commercial production of hydrogen (H2) with zero carbon footprint. Despite this, achieving high solar-to-hydrogen (STH) conversion efficiency with these reactors is still a significant challenge due to the low utilization efficiency of solar light and rapid charge recombination. Herein, hybrid gold nano-islands (HGNIs) are developed on transparent glass support to improve the STH efficiency. Plasmonic HGNIs are grown on an in-house developed active glass sheet composed of sodium aluminum phosphosilicate oxide glass (H-glass) using the thermal dewetting method at 550 °C under an ambient atmosphere. HGNIs with various oxidation states (Au0, Au+, and Au-) and multiple interfaces are obtained due to the diffusion of the elements from the glass structure, which also facilitates the lifetime of the hot electron to be ≈2.94 ps. H-glass-supported HGNIs demonstrate significant STH conversion efficiency of 0.6%, without any sacrificial agents, via water dissociation. This study unveils the specific role of H-glass-supported HGNIs in facilitating light-driven chemical conversions, offering new avenues for the development of high-performance photocatalysts in various chemical conversion reactions for large-scale commercial applications.
RESUMO
A potential adsorbent, Sb4O5Cl2@NbSe2 composite, was generated from the Sb4O5Cl2 photocatalyst and 5 wt % layered 2H-NbSe2 nanoparticles for the highly effective removal of Cr(VI) and Fe(III) ions and methyl orange (MO) from aqueous solution, and a comparison was drawn against the precursors. Sb4O5Cl2 crystallites and NbSe2 nanoparticles were synthesized hydrothermally, and the composite was prepared by the incipient wetness impregnation technique. The crystal structure of Sb4O5Cl2 was determined by single-crystal X-ray diffraction (SCXRD) data. Powder X-ray diffraction (PXRD) study revealed the 2H phase of NbSe2 nanoparticles. Field emission scanning electron microscopy (FESEM) analysis confirmed the formation of the spherical-shaped NbSe2 nanoparticles from rod-shaped bulk 2H-NbSe2. Morphological changes from the hexagonal to irregular prismatic shape were found upon the formation of the Sb4O5Cl2@NbSe2 composite compared to pure Sb4O5Cl2. Negative ζ-potential values indicated that electrostatic interactions were the predominant factor for the adsorption process. Sb4O5Cl2@NbSe2 provided removal efficiencies of 99% for MO in 6 h, 96.52% for Cr(VI) within 2.5 h, and 92.43% for Fe(III) within 4 h of 10 mg/L initial concentration. The maximum adsorption capacities of the composite for MO, Fe(III), and Cr(VI) were found to be 66.56, 131.48, and 122.30 mg/g, respectively, as calculated using the Langmuir isotherm equation.
RESUMO
Metal nanoparticles (MNPs) are synthesized using various techniques on diverse substrates that significantly impact their properties. However, among the substrate materials investigated, the major challenge is the stability of MNPs due to their poor adhesion to the substrate. Herein, it is demonstrated how a newly developed H-glass can concurrently stabilize plasmonic gold nanoislands (GNIs) and offer multifunctional applications. The GNIs on the H-glass are synthesized using a simple yet, robust thermal dewetting process. The H-glass embedded with GNIs demonstrates versatility in its applications, such as i) acting as a room temperature chemiresistive gas sensor (70% response for NO2 gas); ii) serving as substrates for surface-enhanced Raman spectroscopy for the identifications of Nile blue (dye) and picric acid (explosive) analytes down to nanomolar concentrations with enhancement factors of 4.8 × 106 and 6.1 × 105 , respectively; and iii) functioning as a nonlinear optical saturable absorber with a saturation intensity of 18.36 × 1015 W m-2 at 600 nm, and the performance characteristics are on par with those of materials reported in the existing literature. This work establishes a facile strategy to develop advanced materials by depositing metal nanoislands on glass for various functional applications.
