Uniform and reactive hydrogen polysilsesquioxane hollow spheres immobilized with silver nanoparticles for catalytic reduction of methylene blue

Abstract

The facile synthesis of a new class of reactive hydrogen polysilsesquioxane (HPSQ, (HSiO1.5)n,) hollow spheres is reported in this work. HPSQ hollow spheres can be controllably fabricated from triethoxysilane (TES, HSi(OEt)3) as a sole precursor through a polystyrene template-directed sol–gel process under aqueous acid-catalyzed conditions followed by template removal. The particle size and shell thickness of the spheres could be fine-tuned by utilizing different amounts of TES. Total preservation of SiH bonds and formation of a Si-O-Si framework in the HPSQ hollow spheres are confirmed by FTIR and 29Si NMR. Reactive SiH moieties combined with a hollow structure make HPSQs suitable as carriers for noble metal nanoparticles. HPSQ hollow spheres function not only as a host that can adsorb Ag ions but also as a mild reducing agent for these ions. TEM studies show that the synthesized AgNPs are dispersed well on the HPSQ hollow spheres with an average particle size of 2–10 nm. XRD studies indicate that the resulting AgNPs are highly crystalline with a face-centered cubic geometry. SEM-EDS shows that the Ag content on the selected surface is 4.76 wt%. HPSQ hollow spheres loaded with AgNPs exhibit high performance when utilized as a catalyst to reduce methylene blue.