Single-source-precursor synthesis of high temperature stable SiC/C/Fe nanocomposites from a processable hyperbranched polyferrocenylcarbosilane with high ceramic yield

Yu, Zhaoju; Yang, Le; Min, Hang; Zhang, Pei; Zhou, Cong; Riedel, Ralf

doi:10.1039/c3tc32088j

Cited by 63 publications

(50 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…49,50 In the present study, the HfC x N 1−x particles are embedded in a 2-4 nm thick carbon layer (Fig. 27,48,51 However, the mechanism of its formation is not clear yet. As can be seen from the TEM images, the average particle size of HfC x N 1−x annealed at 1400°C and 1700°C amounts to 8 and 37 nm, respectively.…”

Section: Microstructural Evolution Of the As-prepared Ceramicsmentioning

confidence: 59%

Single-source-precursor synthesis of dense SiC/HfC_xN_1−x-based ultrahigh-temperature ceramic nanocomposites

Wen

et al. 2014

Nanoscale

Self Cite

123

View full text Add to dashboard Cite

A novel single-source precursor was synthesized by the reaction of an allyl hydrido polycarbosilane (SMP10) and tetrakis(dimethylamido)hafnium(iv) (TDMAH) for the purpose of preparing dense monolithic SiC/HfC(x)N(1-x)-based ultrahigh temperature ceramic nanocomposites. The materials obtained at different stages of the synthesis process were characterized via Fourier transform infrared (FT-IR) as well as nuclear magnetic resonance (NMR) spectroscopy. The polymer-to-ceramic transformation was investigated by means of MAS NMR and FT-IR spectroscopy as well as thermogravimetric analysis (TGA) coupled with in situ mass spectrometry. Moreover, the microstructural evolution of the synthesized SiHfCN-based ceramics annealed at different temperatures ranging from 1300 °C to 1800 °C was characterized by elemental analysis, X-ray diffraction, Raman spectroscopy and transmission electron microscopy (TEM). Based on its high temperature behavior, the amorphous SiHfCN-based ceramic powder was used to prepare monolithic SiC/HfC(x)N(1-x)-based nanocomposites using the spark plasma sintering (SPS) technique. The results showed that dense monolithic SiC/HfC(x)N(1-x)-based nanocomposites with low open porosity (0.74 vol%) can be prepared successfully from single-source precursors. The average grain size of both HfC0.83N0.17 and SiC phases was found to be less than 100 nm after SPS processing owing to a unique microstructure: HfC0.83N0.17 grains were embedded homogeneously in a β-SiC matrix and encapsulated by in situ formed carbon layers which acted as a diffusion barrier to suppress grain growth. The segregated Hf-carbonitride grains significantly influenced the electrical conductivity of the SPS processed monolithic samples. While Hf-free polymer-derived SiC showed an electrical conductivity of ca. 1.8 S cm(-1), the electrical conductivity of the Hf-containing material was analyzed to be ca. 136.2 S cm(-1).

show abstract

Section: Microstructural Evolution Of the As-prepared Ceramicsmentioning

confidence: 59%

Single-source-precursor synthesis of dense SiC/HfC_xN_1−x-based ultrahigh-temperature ceramic nanocomposites

Wen

et al. 2014

Nanoscale

Self Cite

123

View full text Add to dashboard Cite

show abstract

“…12 The experiments performed by Yu et al have evidenced that BiOI possesses higher photocatalytic activity than Bi 5 O 7 I and Bi 2 O 3 under visible light irradiation. 13 The higher photocatalytic activity of BiOI is attributed to its narrower band gap. Moreover, the heterostructure BiOI/BiOBr 14 and the solid solution xBiOBr-(1Àx)BiOI 15 have been synthesized to enhance photocatalytic performances.…”

Section: Introductionmentioning

confidence: 99%

The stabilities and electronic structures of single-layer bismuth oxyhalides for photocatalytic water splitting

Zhang

Wang

et al. 2014

Phys. Chem. Chem. Phys.

114

View full text Add to dashboard Cite

The stabilities and electronic/band structures of single-layer bismuth oxyhalides have been investigated by employing first-principles calculations. The results indicate that the single-layer bismuth oxyhalide materials, except for BiOF, have robust energetic and dynamical stabilities because of their low formation energies and the absence of imaginary frequencies within the entire Brillouin zone. Furthermore, calculations of the electronic structures and optical absorptions indicate that single-layer BiOI possesses a favorable band gap, suitable band edge positions, different orbital characteristics and different effective masses at the valence band maximum (VBM) and conduction band minimum (CBM), thus presenting excellent photocatalytic activity for water splitting. Moreover, the resulting compressive strains can shift the band edge positions of the single-layer materials to more suitable places to enhance their photocatalytic activities.

show abstract

“…In our previous work, we modified preceramic polymers with iron coordination compounds such as iron pentacarbonyl [Fe(CO) 5 ], acetylacetonate [Fe(acac) 3 ], and vinyl ferrocene (VF) to prepare magnetic Fe‐containing SiC‐ and SiCN‐based ceramic nanocomposites at annealing temperatures beyond 900°C . Despite a few studies with respect to the iron‐modified polycarbosilane, there is a lack of information concerning modification of allylhydridopolycarbosilane (AHPCS) using Fe‐acetylacetonate [Fe(acac) 3 ] as an Fe source and concerning its microstructural evolution and pore formation within the Si‐based ceramic matrix when pyrolyzed at intermediate temperatures below 700°C.…”

Section: Introductionmentioning

confidence: 99%

Template‐Free Synthesis of Porous Fe₃O₄/SiOC(H) Nanocomposites with Enhanced Catalytic Activity

Zhang

Feng

et al. 2016

J. Am. Ceram. Soc.

Self Cite

View full text Add to dashboard Cite

We present a template‐free synthesis of Fe3O4/SiOC(H) nanocomposites with in situ formed Fe3O4 nanoparticles with a size of about 50 nm embedded in a nanoporous SiOC(H) matrix obtained via a polymer‐derived ceramic route. Firstly, a single‐source precursor (SSP) was synthesized by the reaction of allylhydridopolycarbosilane (AHPCS) with Fe‐acetylacetonate [Fe(acac)3] at 140°C. The SSP was heat‐treated at 170°C to generate Fe3O4 nanocrystals in the cross‐linked polymeric matrix. Subsequently, the SSP was pyrolyzed at 600°C–700°C in argon atmosphere to yield porous Fe3O4/SiOC(H) nanocomposites with the high BET surface area up to 390 m2/g, a high micropore surface area of 301 m2/g, and a high micropore volume of 0.142 cm3/g. The Fe‐free SiOC(H) ceramic matrix derived from original AHPCS is nonporous. The in situ formation of Fe3O4 nanoparticles embedded homogeneously within a nanoporous SiOC(H) matrix shows significantly enhanced catalytic degradation of xylene orange in aqueous solution with H2O2 as oxidant as compared with pure commercial Fe3O4 nanoparticles.

show abstract

Single-source-precursor synthesis of high temperature stable SiC/C/Fe nanocomposites from a processable hyperbranched polyferrocenylcarbosilane with high ceramic yield

Abstract: Hydrosilylation of vinyl ferrocene with allylhydridopolycarbosilane was used to synthesize a processable hyperbranched polyferrocenylcarbosilane (HBPFCS).

Cited by 63 publications

References 45 publications

Single-source-precursor synthesis of dense SiC/HfC_xN_1−x-based ultrahigh-temperature ceramic nanocomposites

Single-source-precursor synthesis of dense SiC/HfC_xN_1−x-based ultrahigh-temperature ceramic nanocomposites

The stabilities and electronic structures of single-layer bismuth oxyhalides for photocatalytic water splitting

Template‐Free Synthesis of Porous Fe₃O₄/SiOC(H) Nanocomposites with Enhanced Catalytic Activity

Contact Info

Product

Resources

About

Single-source-precursor synthesis of high temperature stable SiC/C/Fe nanocomposites from a processable hyperbranched polyferrocenylcarbosilane with high ceramic yield

Abstract: Hydrosilylation of vinyl ferrocene with allylhydridopolycarbosilane was used to synthesize a processable hyperbranched polyferrocenylcarbosilane (HBPFCS).

Cited by 63 publications

References 45 publications

Single-source-precursor synthesis of dense SiC/HfCxN1−x-based ultrahigh-temperature ceramic nanocomposites

Single-source-precursor synthesis of dense SiC/HfCxN1−x-based ultrahigh-temperature ceramic nanocomposites

The stabilities and electronic structures of single-layer bismuth oxyhalides for photocatalytic water splitting

Template‐Free Synthesis of Porous Fe3O4/SiOC(H) Nanocomposites with Enhanced Catalytic Activity

Contact Info

Product

Resources

About

Single-source-precursor synthesis of dense SiC/HfC_xN_1−x-based ultrahigh-temperature ceramic nanocomposites

Single-source-precursor synthesis of dense SiC/HfC_xN_1−x-based ultrahigh-temperature ceramic nanocomposites

Template‐Free Synthesis of Porous Fe₃O₄/SiOC(H) Nanocomposites with Enhanced Catalytic Activity