Fig. 2. Characterization of mesoporous silica micro-jets (MSMJs). (A) MSMJ with PtNPs in the inner surface: (a) optical image of a MSMJ, (b) TEM image of a MSMJ, (c) TEM image of the MSMJ surface and (d) STEM image of PtNPs in MSMJ (inset: EELS mapping. PtNPs (green) and silica (red)). (B) EDX analysis of MSMJs. (C) Picture of a MSMJ swimming in aqueous solution (0.5% SDS and 1.5% H₂O₂).