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The melt-quenching method was used to synthesize the samples of the [(75 − x)B2O3–10TeO2–13SrO–2.0ZnO–xPbO (x = 0.0, 5.0, 10, 15, 25, and 40 mol%)]. The peaks found in the XRD patterns were associated with the crystalline phase, Zn2Te3O8, present in these prepared samples. Substituting B2O3 with PbO resulted in a steady density increase from 2.89 to 4.75 g/cm3. The molar volume (Vm) increased from 30.23 to 31.95 cm3/mol as the concentration of PbO went up from 0 to 40 mol%. The Raman analysis confirmed that the increase in PbO content in the compositions led to a conversion from TeO4 to TeO3 and the change of bridging oxygens to non-bridging oxygens. The optical band gap energy, Urbach energy, and other optical properties were analyzed to determine the optical transmission data. As more PbO was added, the optical band gap energy decreased from 3.140 to 2.930 eV, and the Urbach energy rose from 0.337 to 0.377 eV. Under 300 nm excitation, the photoluminescence spectra showed emission bands linked to electronic transitions of Pb2+. [ABSTRACT FROM AUTHOR]

Glass samples comprising Bi2O3, B2O3, TeO2, MgO, and PbO were fabricated using melt quenching. Substituting B2O3 with Bi2O3 resulted in a steady density increase from 2.88 to 7.16 g/cm3 due to the difference in atomic weight between the heavier Bi (208.98 g/mol) and lighter B (10.811 g/mol). As the Bi2O3 concentration rose from 0 to 60 mol%, the molar volume (Vm) gradually increased from 31.02 to 45.69 cm3/mol, owing to the discrepancy in the radii of the Bi3+ and B3+ ions, measuring 0.96 and 0.84 Å, respectively. Increasing the non-bridging oxygens (NBOs) led to a corresponding rise in the molar volume. Incorporating varying concentrations of Bi2O3, ranging from 0 mol% (BMTPBi0) to 60 mol% (BMTPBi60), induced alterations in several physical parameters, consequently affecting the structural characteristics of the glass. Raman analysis confirmed that an increase in Bi2O3 content within the glass composition led to the conversion of TeO4 to TeO3, resulting in the transformation of bridging oxygens into NBOs. As the Bi2O3 content increased, there was a 3.080–2.090 eV decrease in the optical band gap energy as a result of the rise in NBOs (and consequently, an increase in disorder), leading to a rise in Urbach energy from 0.390 to 0.740 eV. The optimal sample was determined as BTMPBi30 due to its balanced properties and potential advantages. The BTMPBi30 as modifier with heavy metal has high transmittance. The band gap energy of BTMPBi30 (2.920 eV) is reasonable and falls within the range suitable for many optical applications. The Urbach energy increases with Bi2O3 content, and for BTMPBi30 (ΔE = 0.480 eV), it is within an acceptable range, indicating a certain level of disorder. Under 300 nm excitation, the photoluminescence spectra indicate distinct emission bands dependent on the species Bi3+ and Pb2+, making BTMPBi30 a potential candidate for applications requiring photoluminescent properties. [ABSTRACT FROM AUTHOR]

Hierarchical structures have recently attracted significant interest due to their exceptional performance in energy storage and catalytic applications. In this study, novel hierarchical Fe2TiO5 nanosheets, fabricated by one-step solvothermal process, for boosted photocatalytic conversion of CO2 with water to fuels, were investigated. The characteristics and properties of these photocatalysts were analyzed using various techniques including XRD, FESEM, TEM, XPS, UV–vis, and PL spectroscopy. The hierarchical Fe2TiO5 nanosheets demonstrated significant performance, yielding 149.5 µmole/g-cat of CH3OH and 61.6 µmole/g-cat of dimethyl ether (DME), respectively. Compared to TiO2 samples, the optimized 2D hierarchical nanosheets of Fe2TiO5 displayed 3.8-fold and 4.1-fold higher efficiency in CH3OH and DME production, highlighting the advantages of their structure. The 2D hierarchical nanosheets of Fe2TiO5 facilitate electron transfer to CO2 due to their unique structure, providing efficient electron pathways and electron storage sites within the nanosheets, thereby enhancing photoactivity. Moreover, the extended stability of Fe2TiO5 in CO2 conversion further confirms the controllable selectivity and stability offered by the 2D hierarchical nanosheets structure. This study suggests that the fabrication of hierarchical structures holds promise for advancing high-performance photocatalysts for solar fuel production through CO2 conversion. [ABSTRACT FROM AUTHOR]