A general strategy towards controllable replication of butterfly wings for robust light photocatalysis

•A general strategy towards controllable replication of butterfly wings was proposed.•Controlled anatase and rutile phase of TiO2 can be realized simply via the tuning of the treatment parameters.•TiO2 replicas exhibit significantly enhanced photocatalytic activity to decompose methylene blue under solar light illumination.•The enhancement can be attributed to a synergy effect of the presence of Ti3+ doping, the air-TO2 interaction, and hierarchical microstructure.•This work offers a scalable and precise approach to replicate various bio-templates based on transition metal oxides.