Double-walled hierarchical porous silica nanotubes loaded Au nanoparticles in the interlayer as a high-performance catalyst.

ABSTRACT

Double-walled hierarchical porous silica nanotubes (NTs) loaded Au nanoparticles (Au NPs) in the interlayer (SiO2@Au@SiO2 NTs) are synthesized by using tetraethoxysilane as silica source and hollow polydivinylbenzene (PDVB) nanowires as the sacrificial templates. The mesopores on the walls and the hollow structure of NTs (macropores) construct the hierarchical porous structure. The SiO2@Au@SiO2 NTs possess a high surface area of 405 m2 g-1 and an average pores size of 4.7 nm. The double-walled structure protects the Au NPs from environmental attacks, which shows an excellent catalytic activity even after reusing 10 times. Meanwhile, the hierarchical porous structure shows excellent catalytic ability and allows the catalytic reaction process to be completed within 5 min. This result indicates that double-walled silica NTs have vast potential in catalysis application due to the special structure.