Assembling core-shell SiO2@NiaCobOx nanotube decorated by hierarchical NiCo-Phyllisilicate ultrathin nanosheets for highly efficient catalytic combustion of VOCs

Abstract

Configuring Ni-based catalyst with superior activity and stability is one efficient strategy in achieving its application for VOCs catalytic combustion. Here, we report the rational design and synthesis of core-shell SiO2@NiaCobOx nanotube derived from three-layered C@SiO2@NiCo-Phyllosilicate nanofiber. Through a typical hydrothermal strategy, the hierarchical NiCo-Phyllosilicate ultrathin nanosheets are fitly grown on the surface of order mesoporous SiO2 nanotube, which is obtained through thermal treatment of core-shell C@SiO2 nanofiber in air. Whereafter, a core-shell SiO2@Ni2Co1Ox nanotube is obtained to achieve the highly efficient conversion of VOCs in the presence of 5vol%H2O. We observe this special structural design can own superior redox ability, provide active oxygen species (Oads), and generate the abundant acid sites. Ideally, the low-temperature catalytic combustion of toluene over the core-shell SiO2@Ni2Co1Ox nanotube is realized through the combined action of Marse-van Krevelen (MvK) and Langmuir-Hinshelwood (L-H) mechanism. Simultaneously, a good thermal stability and water resistance is also achieved, which benefits from the guided growth of order mesoporous SiO2 nanotube, the presence of strong interactions (Ni-O-Si band) and the contribution of surface -OH groups in the special “fibrous” structure of phyllosilicate.