Fig. 1.

The schematic illustrations of soft-enveloping strategy. a The proposed SLS (solid–liquid–solution) three phase interface, in which a solvent (“liquid”) that cannot dissolve metal precursors was used as a surface coating and a barrier layer to prevent metal species from migrating to the outside of the mesoporous channels (“solid”). Next, the transfer of the reducing agent ions (“solution”) across the solvent and then the reduction of the metal precursor at the interface of the “solid” and “solution”. b The present challenge is that the final product mixes with the morphologies containing the bulk particles. c The current soft-enveloped SLS interface reaction protocol