Enhanced Thermal Stability under DC Electrical Conductivity Retention and Visible Light Activity of Ag/TiO₂@Polyaniline Nanocomposite Film

The development of organic–inorganic photoactive materials has resulted in significant advancements in heterogeneous visible light photocatalysis. This paper reports the synthesis of visible light-active Ag/TiO₂@Pani nanocomposite film via a simple biogenic–chemical route. Electrically conducting Ag/TiO₂@Pani nanocomposites were prepared by incorporating Ag/TiO₂ in <i>N</i>-methyl-2-pyrrolidone solution of polyaniline (Pani), followed by the preparation of Ag/TiO₂@Pani nanocomposite film using solution casting technique. The synthesized Ag/TiO₂@Pani nanocomposite was confirmed by UV–visible spectroscopy, photoluminescence spectroscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The Ag/TiO₂@Pani nanocomposite film showed superior activity towards the photodegradation of methylene blue under visible light compared to Pani film, even after repeated use. Studies on the thermoelectrical behavior by DC electrical conductivity retention under cyclic aging techniques showed that the Ag/TiO₂@Pani nanocomposite film possessed a high combination of electrical conductivity and thermal stability. Because of its better thermoelectric performance and photodegradation properties, such materials might be a suitable advancement in the field of smart materials in near future

Facile Synthesis of SnS₂ Nanostructures with Different Morphologies for High-Performance Supercapacitor Applications

SnS₂ is an emerging candidate for an electrode material because of the considerable interlayer spaces in its crystal structures and the large surface area. SnS₂ as a photocatalyst and in lithium ion batteries has been reported. On the other hand, there are only a few reports of their supercapacitor applications. In this study, sheetlike SnS₂ (SL-SnS₂), flowerlike SnS₂ (FL-SnS₂), and ellipsoid-like SnS₂ (EL-SnS₂) were fabricated via a facile solvothermal route using different types of solvents. The results suggested that the FL-SnS₂ exhibited better capacitive performance than the SL-SnS₂ and EL-SnS₂, which means that the morphology has a significant effect on the electrochemical reaction. The FL-SnS₂ displayed higher supercapacitor performance with a high capacity of approximately ∼431.82 F/g at a current density of 1 A/g. The remarkable electrochemical performance of the FL-SnS₂ could be attributed to the large specific surface area and better average pore size. These results suggest that a suitable solvent is appropriate for the large-scale construction of SnS₂ with different morphologies and also has huge potential in the practical applications of high-performance supercapacitors

Defect-Induced Band Gap Narrowed CeO₂ Nanostructures for Visible Light Activities

This work reports an electron beam irradiation (30 kGy and 90 kGy) approach to narrow the band gap of the pristine CeO₂ nanostructure (p-CeO₂) to enhance their visible light activity through defect engineering. This was confirmed by diffuse reflectance spectroscopy, photoluminescence, Raman spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller, electrochemical impedance spectroscopy, and linear scan voltammetry. XPS revealed changes in the surface states, composition, Ce⁴⁺ to Ce³⁺ ratio, and other defects in the modified CeO₂ nanostructures (m-CeO₂). The m-CeO₂ exhibits excellent photocatalytic activities by degrading 4-nitrophenol and methylene blue in the presence of visible light (λ > 400 nm) compared to the p-CeO₂. The optical, photocatalytic, and photoelectrochemical studies and proposed mechanism further support the enhanced visible light photocatalytic activities of the m-CeO₂. This study confirmed that defect-induced band gap engineered m-CeO₂ could be used effectively as photocatalyst and photoelectrodes owing to their enhanced visible light photocatalytic activities