Self-assembled nano-leaf/vein bionic structure of TiO2/MoS2 composites for photoelectric sensorsElectronic supplementary information (ESI) available. See DOI: 10.1039/c7nr06902b

Inspired by the leaf/vein structure of leaves which effectively supports the photosynthesis of green plants, a nano-leaf/vein bionic structure of self-assembled TiO 2 /MoS 2 composites is applied to induce the reversible photochromic reactions of methylene blue (MB) for the first time. This reversible photochromic phenomenon gives a novel performance for the TiO 2 /MoS 2 composites and expands their applications. Similar to the case where the natural vein network in leaves ensures the efficient material transfer and energy exchange for photosynthesis, the bionic internal MoS 2 vein network in the composites ensures the efficient separation and directional transfer of photo-generated carriers to restrain the photocatalytic degradation reactions and to enhance the reversible photochromic reactions. Furthermore, the photosensitive applications of the TiO 2 /MoS 2 /MB systems with such a self-assembled nano-leaf/vein bionic structure are discussed with two typical photoelectric sensory models for both controllers and detectors. A self-assembled nano-leaf/vein structure of TiO 2 /MoS 2 composites which can induce reversible photochromic reactions of methylene blue (MB) is fabricated and the potential applications of TiO 2 /MoS 2 /MB system in photoelectric sensors are demonstrated.