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In recent times cost-effective advanced materials with dual applications in photocatalytic water treatment and electrochemical sensing have been explored and developed. Herein we report facile solution combustion synthesis of ZnO/Fe 2 O 3 (ZF) type-II heterojunction for electrochemical sensing of dopamine and visible assisted photocatalytic reduction of carcinogenic Cr(VI) into Cr(III). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to evaluate the compatibility of the electrodes for DA sensing. Furthermore, DPV curves revealed that ZF2 (ZnO: Fe 2 O 3 - 3:0.5) modified GCEs possessed 0.27 μM and 0.7 μM of LOD and LOQ with good linear range from 3 μM to 30 μM. Overall, reproducibility and interference studies confirm the efficient use of material for DA sensing. The junction ZF2 shows best performance with 88% Cr(VI) photo-reduction under visible light in 90 min and 100% reduction with tartaric acid as sacrificial agent (utilizing holes) in just 45 min. The effect of sacrificial agents and scavengers suggest the photogenerated electrons were major active species followed by ●O 2 −. The CB edges have enough potential for rapid reduction of hexavalent chromium under visible light and solar light. The photoluminescence and electrochemical impedance suggest lowered recombination, high charge separation and charge transfer capacity in the heterojunction. The transfer of electrons from conduction band of Fe 2 O 3 to that of ZnO having high enough negative potential to reduce Cr(VI), thus utilizing the CB potential of wide band gap ZnO for rapid visible photocatalysis. In addition shortcomings as low conductivity Fe 2 O 3 and high band gap of ZnO are both minimized in the junction. This study confirmed that popular semiconductors as ZnO and Fe 2 O 3 have enough potential in dual role as electrochemical sensors and visible photocatalysts with best performance by optimizing the conditions and ratios. Image 1 [ABSTRACT FROM AUTHOR]

In this paper, we report the fabrication and systematic characterization of Fe Doped ZnO thin Films. Fe x Zn 1− x O ( x =0<0.05) films were prepared by RF magnetron sputtering on Si (400) substrate. Influence of Fe doping on structural, optical and magnetic properties has been studied. The X-ray diffraction (XRD) analysis shows that Fe doping has affected the crystalline structure, grain size and strain in the thin films. The best crystalline structure is obtained for 3% Fe Doping as observed from Atomic Force Microscopy (AFM) and X-ray diffraction (XRD). The magnetic properties studied using Vibrating Sample Magnetometer reveals the room temperature ferromagnetic nature of the thin films. However, changing the Fe concentration degrades the magnetic property in turn. The mechanism behind the above results has been discussed minutely in this paper. [ABSTRACT FROM AUTHOR]

Mg0.9Mn0.1Gd x Fe2-x O4 nanoferrites were processed for the first time by a solution combustion technique. X-ray diffraction studies revealed the spinel cubic structure of the synthesized ferrites. The particle size was observed to increase (13-16nm) with an increase in Gd3+ ion content. The cation distribution is inferred from the X-ray diffraction. It is observed from cation distribution that Gd3+ ions preferred octahedral (B) sites. The DC resistivity was found to be increasing with an increase in Gd3+ content. The dielectric constant ε' and loss tangent (tan &#948) was observed to decrease with the addition of Gd3+ content as well as with the increase in frequency. The variations in DC resistivity as well as dielectric constant with the increasing substitution of Gd3+ ions have been correlated to the cation distribution. The very high values of DC resistivity (~108 Ωcm) and low values of loss tangent (0.9-0.008) are the prime achievements of this work. [ABSTRACT FROM AUTHOR]