Semiconductor materials have received substantial attention as photocatalysts for controlling water pollution. Among these materials, perovskite-structured SrSnO 3 is a promising candidate for this application, whereas BaSnO 3 exhibits very low activity. In the present work, Sr 1-x Ba x SnO 3 (x = 0, 0.25, 0.50, 0.75 and 1) was synthesized by solid-state reaction and was applied in the photocatalytic discoloration of the organic dye Remazol Golden Yellow. The perovskite structure was obtained for all compositions of the solid solutions with both Sr The two materials appear to feature different mechanisms of photodegradation: the direct mechanism prevails in the case of BaSnO 3 , whereas the indirect mechanism appears to play a key role in the case of SrSnO 3 .

Tin dioxide (SnO 2) gas sensors with reliable sensing properties and low-cost are most desired for application in the detection of hazardous gases in heavy industries, 1,2 in-house safety monitoring, 3 and food quality control. 4 Most SnO 2based gas sensors are formed by a single heated layer of sensing material deposited over a pair of electrodes, which usually needs high operating temperatures (200-400ºC) to achieve their most desirable sensing response. 3,

The inadequate discharge of effluents from different sources without prior treatment can impact the characteristics of soil and water, which reflect serious environmental problems. Advanced oxidative processes (AOP) appear as a viable alternative for environmental remediation, including wastewater treatment. Herein, α-MoO3 and α-Fe2O3 semiconductors were synthesized at low temperature by a Pechini-based method and then applied in photocatalysis. The catalytic efficiency was performed under visible light toward the degradation of an organic persistent pollutant (Rhodamine B dye, RhB), commonly present in industries wastewater. The results indicated that the synthesized α-MoO3 or α-Fe2O3 photocatalysts presented a pronounced activity and promoted an efficient RhB degradation after 15 min of reaction. α-MoO3 had a degradation efficiency of 93% and 98%, while α-Fe2O3 showed 67% and 100% RhB degradation without and with the addition of H2O2, respectively. These results suggest that the synthesized oxides have high oxi-reductive capacity, which can be used for a fast and effective photodegradation of RhB and other organic persistent pollutants to minimize environmental impacts.

No abstract

No abstract

CaFe2O4 nanofibers were successfully synthesized via solution blow spinning (SBS), and the influences of heat-treatment on morphological, microstructural, magnetic, and optical properties of the nanofibers were evaluated. In the synthesis process, stoichiometric amounts of iron and calcium nitrates were dissolved in an aqueous solution containing polyvinylpyrrolidone (PVP) and, after that, hybrid nanofibers (PVP/precursors) were produced by SBS. The hybrid nanofibers were calcined and then subjected to microstructural, morphological, and magnetic characterizations. The results evidenced that the fibers presented the crystalline nature of the single-phase CaFe2O4, with a crystallite size of 32.7 and 34.4 nm for the samples calcined at 800 and 1000 °C, respectively. The CaFe2O4 fibers calcined at 600 and 800 °C presented a homogeneous morphology, without beads, and mean diameters of 521 and 427 nm, respectively. The results also revealed nanofibers with low band gaps of approximately 1.98 eV and characteristics of soft magnetic materials.

No abstract

Bulk nanocrystalline samples of (La1−xPrx)0.67Ba0.33MnO3 (0.075 ≤ x ≤ 0.30) manganites with a fixed carrier concentration are prepared by the sol–gel based Pechini method.