Supporting information

Carbon nanofiber-supported PdNi alloy nanoparticles as highly efficient bifunctional

catalysts for hydrogenand oxygen evolution reactions

Jiawei Chen, Jiadong Chen, Danni Yu, Ming Zhang*, Han Zhu, Mingliang Du

College of Materials and Textiles, Zhejiang Sci-Tech University, Hangzhou 310018, PR China;

Tel: 86-571-86843255; Fax: 86-571-86843255; E-mail: zhangming@zstu.edu.cn

Fig. S1 FE-SEM images of (a) PdNi/CNFs-1:0.5; (b) PdNi/CNFs-1:1; (c) PdNi/CNFs-1:2 ; (d) PdNi/CNFs-1:4.

Fig. S2 XRD patterns of the PdNi/CNFs-1:0.5, PdNi/CNFs-1:1, PdNi/CNFs-1:2, PdNi/CNFs-1:4.

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Fig. S3 Hydrogen evolution reaction electrocatalysis in 0.5 M H2SO4. (a) polarization curves and (b) corresponding Tafel plots of the PdNi/CNFs-1:0.5, PdNi/CNFs-1:1, PdNi/CNFs-1:2 and PdNi/CNFs-1:4; (c-d) the CV plots of the Pd/CNFs, Ni/CNFs at scan rates of 20-200 mV s-1.

Fig.S4 HER in 0.5 M H2SO4.(a) Polarization curves of the PdNi/CNFs-1:2 electrode before and after 1000 potential cycles (scan rate: 01 V s-1); Inset is CV curves of the indicated electrode

before and after potential cycles; (b) TEM image of PdNi/CNFs-1:2 after 1000 potential cycles; OER in 1M KOH;(c) Polarization curves of the PdNi/CNFs-1:2 electrode before and after 1000 potential cycles (scan rate: 100 mV s-1); Inset is CV curves of the indicated electrode before and

after potential cycles; (d) TEM image of PdNi/CNFs-1:2 after 1000 potential cycles.

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Fig. S5 (a) The changes of element content of Ni and Pd for the PdNi/CNFs-1:2 before and after electrochemical stability test through the EDS spectra; (b) XRD patterns of the PdNi/CNFs-1:2

before and after stability test.

Fig. S6 OER and HER electrocatalysis in 1 M KOH. (a) Polarization curves and (b) corresponding Tafel plots of the PdNi/CNFs-1:0.5, PdNi/CNFs-1:1, PdNi/CNFs-1:2 and PdNi/CNFs-1:4 for

OER; (c) polarization curves and (d) corresponding Tafel plots of the PdNi/CNFs-1:0.5, PdNi/CNFs-1:1, PdNi/CNFs-1:2 and PdNi/CNFs-1:4 for HER.

Table S1 The comparison of HER activity among recently reported various electrocatalysts.

Catalystsη at 10 mA cm-2

(mV)Tafel slope(mV dec-1)

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Table S2 The comparison of OER activity among recently reported various electrocatalysts.

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