Quantum scale biomimicry of low dimensional growth : an unusual complex amorphous precursor route to TiO2 band confinement by shape adaptive biopolymer-like flexibility for energy applications

• Main Authors: Choi, Dahyun, Sonkaria, Sanjiv, Fox, Stephen John, Poudel, Shivraj, Kim, Sung-yong, Kang, Suhee, Kim, Seheon, Verma, Chandra, Ahn, Sung Hoon, Lee, Caroline Sunyong, Khare, Varsha
• Other Authors: School of Biological Sciences
• Format: Article
• Language: English
• Published: 2020
• Subjects: Science::Biological sciences; Biomimicry; TiO2
• Online Access: https://hdl.handle.net/10356/142615
• Institution: Nanyang Technological University

Crystallization via an amorphous pathway is often preferred by biologically driven processes enabling living species to better regulate activation energies to crystal formation that are intrinsically linked to shape and size of dynamically evolving morphologies. Templated ordering of 3-dimensional space around amorphous embedded non-equilibrium phases at heterogeneous polymer─metal interfaces signify important routes for the genesis of low-dimensional materials under stress-induced polymer confinement. We report the surface induced catalytic loss of P=O ligands to bond activated aromatization of C-C C=C and Ti=N resulting in confinement of porphyrin-TiO2 within polymer nanocages via particle attachment. Restricted growth nucleation of TiO2 to the quantum scale (≤2 nm) is synthetically assisted by nitrogen, phosphine and hydrocarbon polymer chemistry via self-assembly. Here, the amorphous arrest phase of TiO2 is reminiscent of biogenic amorphous crystal growth patterns and polymer coordination has both a chemical and biomimetic significance arising from quantum scale confinement which is atomically challenging. The relative ease in adaptability of non-equilibrium phases renders host structures more shape compliant to congruent guests increasing the possibility of geometrical confinement. Here, we provide evidence for synthetic biomimicry akin to bio-polymerization mechanisms to steer disorder-to-order transitions via solvent plasticization-like behaviour. This challenges the rationale of quantum driven confinement processes by conventional processes. Further, we show the change in optoelectronic properties under quantum confinement is intrinsically related to size that affects their optical absorption band energy range in DSSC.