Holographic polymer nanocomposite, as an important ordered polymer-based composite, has attracted more and more attentions due to its applications, such as photonic crystals, microlenses, mirrorless tunable lasers, data and 3D image storage, 3D display, diffractive and reflective optical elements. Recently, we proposed a novel, visible light sensitive "photoinitibitor", which is able to simultaneously generate two distinct radicals with initiation and inhibition functions for each separately under monochromatic visible light. The Janus-faced functions of the photoinitibitor delay gelation and dramatically amplify the gelation time difference between the constructive and destructive interference regions, which is beneficial to the photopolymerization induced phase separation of binary and ternary polymer nanocomposites of photopolymer, liquid crystals and zinc sulfide (ZnS) nanoparticles during holographic recording. Based on Fick’s Second Law, we established a novel exponential correlation between segregation degree (SD) and the ratio of photopolymerization gelation time to holographic mixture viscosity. Finally, we reconstruct and display colored 3D holographic images, and fabricate high performance electro-optical devices with high diffraction efficiency and low driving voltage. Keywords: Polymer nanocomposites, phase segregation, image storage, electro-optical device, holographic recording Acknowledgements: This work was supported by Key Program of National Natural Science Foundation of China (51433002).