Photon upconversion, morphology dependent magnetic property, a high sensitive non-enzymatic hydrogen peroxide and hydrazine electrochemical sensing study of 3D micro-snowflake structured α-Fe2O3

16^th International Conference on Emerging Materials and Nanotechnology

March 22-23, 2018 | London, UK

S. Majumder , B. Saha, S. Kumar and S. Banerjee

Jadavpur University, India
Saha Institute of Nuclear Physics, India

Posters & Accepted Abstracts: J Material Sci Eng

Abstract :

In this manuscript we have successfully synthesized a large scale 3D dendritic �±-Fe2O3 hierarchical structure via a hydrothermal reaction1. The crystallinity, composition, purity, morphology of the synthesized �±-Fe2O3 is characterized by PXRD, FESEM, TEM, EDS, FTIR and Mossbauer analysis. The FESEM and TEM images reveal that the sample exhibit micro-snowflake like shape having six-fold symmetry with symmetric branching along each arm consists of a long central trunk and secondary branches. Various shape and morphology of �±-Fe2O3 have been modeled on the basis of their growth evolution. The UV-Vis spectra shows visible light absorption and PL exhibiting a peak near UV region indicates up-conversion property. So, we can use this sample for visible light mediated catalysis applications, photodectector and photo-voltaic application purposes. Here the effect of morphology of �±-Fe2O3 on their magnetic property has been studied by M-T (100 Oe applied field) and M-H (at 10K, 100K, 300K). The variation in surface adsorbed OH- ions causes surface spin pinning, and as a result, the spin relaxation mechanism is disturbed, results to higher coercivity. The spin pinning and the associated magnetic surface anisotropy are the possible reason for increase in coercivity. At low temperature Exchange bias has been observed. Cyclic voltammetry (CV) study indicates that this �±-Fe2O3 structure shows excellent performance towards hydrogen peroxide (H2O2) reduction and hydrazine (N2H4) oxidation in alkaline medium. Further, amperomatric I-t measurements show a high sensitivity of 7.16 �µA/mM/cm2 in a wide range of 0.1-5.5 mM with the limit of detection of 0.01 mM (S/N=3) towards H2O2 sensing. The sample also exhibits a good sensitivity of 24.03 �µA/mM/cm2 in the linear range between 50 �µM and 1340 �µM with the limit of detection of 5 �µM towards hydrazine detection1. Good reproducibility, stability and selectivity suggest its suitability for fabrication of H2O2 and hydrazine sensor. sumitmajumder2779@gmail.com