Electronic Supplementary

Electronic Supplementary

In-situ growth of Co3O4 nanoparticles on mesoporous carbon nanofibers: a new nanocomposite for nonenzymatic amperometric sensing of H2O2

Yue Ni a,b, Yuan Liaoa, b, Mingbo zhengc, *, Shijun Shao a,*

aCAS Key Laboratory of Chemistry of Northwestern Plant Resources of CAS and Key Laboratory for Natural Medicine of Gansu Province, Lanzhou institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, P. R. China.

b University of Chinese Academy of Sciences, Beijing 100039, P. R. China.

cSchool of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, P. R. China.

* Corresponding author: Tel: +86-931-4968209; Fax: +86-931-8277088; E-mail:,

Fig. S1.Nitrogen adsorption-desorption isotherms and BJH pore size distribution curve from adsorption branch (inset) of MCNFs.

The BET surface area and the total pore volume of MCNFs were determined to be 1420.2 m2 g-1 and 3.5 cm3 g-1, respectively.

Fig. S2.Typical XRD patterns of MCNFs and Co3O4-MCNFs nanocomposites.

MCNFs exhibited two broad peak at around 23o and 43o, corresponding to the (0 0 2) and (1 0 0) planes. The XRD spectrum of Co3O4-MCNFs nanocomposites showed that the diffraction peaks at 2θ values of 31.18o, 36.93o, 44.73o, 59.30o and 65.31o correspond to (2 2 0), (3 1 1), (4 0 0), (5 1 1) and (4 4 0) crystal planes, respectively.

Fig. S3.XPS survey spectra of Co3O4-MCNFs (a) and deconvoluted high resolution XPS spectra of Co 2p (b).

As shown in the Co 2p XPS spectra (Fig. S3b), there were two characteristic peaks centered at 780.6 and 796.2 eV, which corresponded to Co 2p3/2 and Co 2p1/2 spin-orbit peaks of the Co3O4 phase, respectively.

Fig. S4.(a) CVs of 1 mM H2O2 on the Co3O4-MCNFs/Nafion/GCE at different scan rates: From inner to outer: 20, 40, 60, 80, 100, 120, 140, 160, 180 and 200 mV/s. inset is the calibration curve of redox peak current to the scan rate. (b) CV responses of the Co3O4-MCNFs/Nafion/GCE with different concentrations of H2O2 (from 0 to 2.0 mM) in 0.1 M NaOH solution at a scan rate of 100 mV s-1.

The linear relationship between the redox peak currents (anodic peak at about 0.2 V and cathodic peak at -0.4 V) and the scan rate was: Ipa(μA)=20.16+386.86v(V/s), R2=0.994; Ipc(μA)=-35.04-411.51v(V/s), R2=0.998.

Table S1 Recovery data for the determination of H2O2 in simulated milk samples using thecalibration curve method.

H2O2 added (mM) / H2O2 found (mM) / RSDa (%) / Recovery (%)
0 / - / - / -
0.005 / 0.00499 / 0.69 / 99.81
0.01 / 0.0099 / 1.79 / 99.02
0.02 / 0.01984 / 0.03 / 99.19
0.05 / 0.0481 / 1.29 / 96.19

aCalculated as a mean of three measurements