A new cathodic scheme for hydrogen peroxide (H 2 O 2 ) measurement by Fe 3 O 4 -based chemical sensor was described. The unique characteristic of electrocatalytic property was firstly investigated by voltammetry. And then the amperometric response of H 2 O 2 was measured at À 0.2 V (vs. Ag/AgCl) by Fe 3 O 4 modified glassy carbon rotating disk electrode. The kinetic parameter was also calculated from Koutecky-Levich plot, and the value was 6.4 Â 10 À4 cm s À1 in pH 3 citrate buffer. In order to benefit the possible biomedical applications, Fe 3 O 4 /chitosan modified electrode was also investigated in this experiment. There were several characteristic enhancements by the coated chitosan thin film for H 2 O 2 sensor. The calibration curves were found to be linear up to 4.0 and 5.0 mM (r ¼ 0.999) in pH 3 and 7 with the detection limits of 7.6 and 7.4 mM L À1 (S/N ¼ 3). The stability was evaluated by the results of half-life time (t 50% ) for 9 months at room temperature and 24 months at 4 8C.

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Iron(III) hexacyanoferrate(II), Fe4III[FeII(CN)6]3, has been used to modify the LiMn2O4 (LMO) cathodes for improving the high rate performances of lithium ion batteries. Iron(III) hexacyanoferrate(II) is a mixed valence compound with electronic and ionic conductivity, which differs from conventional inert modification materials for LMO cathodes. Both thin film and powder type cathodes have been investigated. The modified LMO cathodes can be discharged at high C-rates and still deliver applicable capacities, which satisfies the requirement of electric vehicles. The enhanced high rate performances can be attributed to the reduced interface charge transfer resistances due to iron(III) hexacyanoferrate(II) modification, as measured by the electrochemical impedance spectra.

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