Structural design, biomimetic synthesis, and environmental sustainability of graphene-supported g-C3N4/TiO2 hetero-aerogels

As an important semiconductor photocatalytic material, titanium oxide (TiO2) has attracted increasing attention in photocatalytic degradation of organic pollutants due to its high oxidation ability, long-term photostability, and non-toxicity. In this work, we propose a green, facile, efficient, and sustainable strategy to mineralize TiO2 nanocrystals on biomolecules using biomimetic synthesis. Different from previous reports, we used short peptides with different functional sequences to carry out the biomimetic growth of TiO2 in the process of peptide self-assembly to obtain peptide nanofiber (PNF)-TiO2 nanohybrids with controllable structure. In subsequent applications, the biomimetic synthesized PNF-TiO2 nanohybrids were non-covalently cross-linked with graphene oxide (GO) and graphitic carbon nitride (g-C3N4) and freeze-dried to obtain nanohybrids with heterostructured aerogels (hetero-aerogels). The GO/PNF/g-C3N4-TiO2 hetero-aerogel exhibits good photocatalytic activity after thermal annealing and exhibits rapid photocatalytic degradation of methylene blue (MB) and rhodamine B (RhB). Finally, the sustainability of the hetero-aerogels is evaluated using the ranking efficiency product (REP) method. The strategy for preparing TiO2-functionalized hetero-aerogels via biomimetic synthesis in this study is green, economical, and efficient, and the obtained hetero-aerogels are expected to reveal wide applications in the fields of energy storage, wearable devices, environmental science, and analytical science. More importantly, in future research, we can prepare TiO2 nanohybrids with different requirements by controlling the structure and morphology of the biological template self-assembly for application in more fields.