Core–shell particles are desirable for many applications, but the precise design and control of their structure remains a great challenge. In this work, we developed a strategy to fabricate carbon-coated SiO x (SiO x @C) core–shell particles via a sol–gel method using the simultaneous hydrolysis–condensation of tetramethyl orthosilicate (TMOS), the polymerization of 3-aminophenol and formaldehyde in the presence of ammonia as a basic catalyst, and cetyl­tri­methyl­am­monium bromide (CTAB) as a cationic surfactant in the mixed solution of water and methanol followed by the carbonization process. Results from this study provide new insight into the design of core–shell particles by using TMOS as an effective silica precursor for the first time with a well-controlled reaction rate and spherical morphology. To obtain an in-depth understanding of the formation of core–shell structure, a possible mechanism is also proposed in this article. When tested as an anode material for lithium ion batteries (LIBs), the obtained SiO x @C particles delivered a reversible capacity of 509.2 mAh g–1 at a current density of 100 mA g–1. This electrochemical performance is significantly better than those of similar composites without the core–shell structure. The capacity retention after 100 cycles was approximately 80%. These results suggest great promise for the proposed SiO x @C particles with core–shell structure, which may have potential applications in the improvement of various energy-storage materials.

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A C/SiO 2 composite was produced from 3-aminophenol and tetraethyl orthosilicate (TEOS) by a synthesis protocol that involved microwave irradiation. This protocol featured simultaneous 3-aminophenol polymerization and TEOS hydrolysis and condensation, which were achieved rapidly in a microwave reactor. The SiO 2 component was formed from low-concentration TEOS confined in cetyltrimethylammonium bromide micelles. We demonstrated a control of the SiO 2 particle size, ranging from 20 to 90 nm, by varying the 3-aminophenol concentration. The carbon component provided a microporous structure that greatly contributed to the high specific surface area, 375 m 2 /g, and served as a host for the nitrogen functional groups with a content of 5.34%, 74% of which were pyridinic type. The composite formation mechanism was clarified from time-series scanning electron microscopy images and dynamic light scattering analysis. An understanding of the composite formation mechanism in this protocol will enable the design of composite morphologies for specific applications.