Sn-containing mesoporous silica nanospheres (Sn-MSNSs) with uniform crater-like mesopores were successfully synthesized by a direct synthetic method. The effects of Sn content and calcination temperature on the structural properties of Sn-MSNSs were investigated. Moreover, the catalytic performance of SnMSNSs in the Baeyer-Villiger (BV) oxidation of bulky cyclic ketone with hydrogen peroxide (H2O2) was studied. Compared with Sn-MCM-41, which possessed long mesopores, Sn-MSNSs with high hydrophobicity provided by high-temperature calcination exhibited much higher activity in the BV oxidation of bulky cyclic ketone, 2-adamantanone. (C) 2014 Elsevier B.V. All rights reserved.