Supplementary material (ESI) for Journal of Materials Chemistry This journal is © The Royal Society of Chemistry 2006

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Supporting Information

Periodic mesoporous organosilica mesophases are versatile

precursors for the direct preparation of mesoporous

silica/carbon composites, carbon and silicon carbide materials

Zhuxian Yang, Yongde Xia, and Robert Mokaya*

School of Chemistry, University of Nottingham, Nottingham, NG7 2RD, UK

Ten additional figures showing; low angle region XRD patterns of mesoporous organosilica

mesophase before and after calcination, TEM images of silica/carbon composites and

nanoporous/mesoporous silica, high angle XRD patterns of silica/carbon composites, TGA curves

of silica/carbon composites and silicon carbide, pore size distribution (PSD) curves of

mesoporous carbon and silicon carbide and SEM images of silicon carbide.

Supplementary material (ESI) for Journal of Materials Chemistry This journal is © The Royal Society of Chemistry 2006

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2 θ (degree)

0 2 4 6 8 10

Inte

nsity

(a. u

.)

a

b

Supporting Figure S1. XRD patterns of ethyl-bridged organosilica mesophase before (a) and after

(b) template (CTAB) removal by refluxing in ethanol/HCl solution to generate the mesoporous

organosilica. The XRD pattern of the template free organosilica exhibits a high intensity basal

(100) peak along with (110) and (200) peaks, and therefore confirms that the mesophase has

hexagonal (p6mm) pore channel ordering.

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Supporting Figure S2. TEM images of silica/carbon composites prepared by pyrolysis of

ethyl-bridged organosilica mesophase under argon flow at 800 °C.

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Supporting Figure S3. TEM images of (a) mesostructured silica/carbon composites prepared by

pyrolysis of ethyl-bridged organosilica mesophase under argon flow at 1100 °C and (b)

nanostructured silica obtained via calcination of the silica/carbon composite in air at 550 oC. The

inset in (a) is selected area electron diffraction (SAED) pattern; the SAED pattern shows rings that

may be ascribed to some limited graphitic ordering for the carbon component of the silica/carbon

composite.

Supplementary material (ESI) for Journal of Materials Chemistry This journal is © The Royal Society of Chemistry 2006

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2 θ (degree)

10 20 30 40 50 60

Inte

nsity

(a. u

.)

a

b

c

Supporting Figure S4. XRD patterns (wide angle) of silica/carbon composites prepared by

pyrolysis of mesoporous ethyl-bridged organosilica at various temperatures under argon

flow: (a) 800, (b) 950, (c) 1100 °C.

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Temperature (oC)

0 100 200 300 400 500 600 700 800 900

Mas

s (%

)

a

b

c

2.5

Supporting Figure S5. TGA curves of nanostructured silica obtained via calcination (in air at 550 oC) of silica/carbon composites prepared by pyrolysis of mesoporous ethyl-bridged organosilica

at various temperatures under argon flow; (a) 800, (b) 950, (c) 1100 °C. The TGA curves,

obtained under static air conditions, show that the nanostructured silicas are virtually carbon free;

there is no significant mass loss up to 900 oC. This indicates that all the carbon is removed during

calcination of the silica/carbon composites.

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Supporting Figure S6. TEM images of nanostructured silica (Silica800) obtained via calcination

in air at 550 oC of silica/carbon composite prepared by pyrolysis of ethyl-bridged organosilica

mesophase under argon flow at 800 °C.

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pore size (nm)0 2 4 6 8 10 12 14

dV/d

D (c

m3 g-1

nm-1

)

0.00

0.01

0.02

Carbon800

Carbon950

Supporting Figure S7. Pore size distribution (PSD) curves of carbon materials obtained via

silica etching in hydrofluoric acid of silica/carbon composites prepared by pyrolysis of

ethyl-bridged organosilica mesophases at 800 oC (Carbon800) or 950 oC (Carbon950). The

PSD curves were obtained using the Howarth-Kawazoe method assuming spherical pores.

Supplementary material (ESI) for Journal of Materials Chemistry This journal is © The Royal Society of Chemistry 2006

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Temperature (oC)

0 200 400 600 800 1000

Mas

s (%

)

0

20

40

60

80

100

120

Supporting Figure S8. TGA curve of nanostructured silicon carbide obtained via calcination (in

air at 700 oC/3h), HF-treatment and further calcination (in air at 700 oC/1h) of silica/carbon/SiC

composite prepared by pyrolysis of mesoporous ethyl-bridged organosilica at 1300 °C under

argon flow. The TGA curves, obtained under static air conditions, show that the nanostructured

SiC is carbon free as there is no mass loss up to 1000 oC.

Supplementary material (ESI) for Journal of Materials Chemistry This journal is © The Royal Society of Chemistry 2006

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pore size (nm)0 2 4 6 8 10 12 14

dV/d

D (c

m3 g-1

nm-1

)

0.008

0.010

0.012

0.014

0.016SiC

Supporting Figure S9. Pore size distribution (PSD) curve of SiC sample obtained from

SiC/carbon/silica composite pyrolysed at 1350 oC after calcination (700 oC/3h in air),

HF-treatment and further calcination (700 oC/1h in air) of the composite. The PSD curve

was obtained via BJH analysis of nitrogen adsorption data.

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Supporting Figure S10. Representative SEM images of nanostructured silicon carbide. The silicon

carbide was obtained via pyrolysis of ethyl-bridged organosilica mesophase under argon flow at

1300 oC followed by calcination (700 oC/3h in air) and HF treatment to remove excess carbon and

silica respectively.