Fabrication of Crack-Free Photonic Crystal Films on Superhydrophobic Nanopin Surface

On the basis of their superior optical performance, photonic crystals (PCs) have been investigated as excellent candidates for widespread applications including sensors, displays, separation processes, and catalysis. However, fabrication of structurally controllable large-area PC assemblies with no defects is still a tough task. Herein, we develop an effective strategy for preparing centimeter-scale crack-free photonic crystal films by the combined effects of soft assembly and superhydrophobic nanopin surfaces. Owing to its large contact angle and low-adhesive force on the superhydrophobic substrate, the colloidal suspension exhibits a continuous retraction of the three-phase (gas–liquid–solid) contact line (TCL) in the process of solvent (water molecules) evaporation. The constantly receding TCL can bring the colloidal spheres closer to each other, which could timely close the gaps due to the loss of water molecules. As a result, close-packed and well-ordered assembly structures can be easily obtained. We expect that this work may pave the way to utilize novel superhydrophobic materials for designing and developing high-quality PCs and to apply PCs in different fields

Protein-Directed Synthesis of Bifunctional Adsorbent-Catalytic Hemin-Graphene Nanosheets for Highly Efficient Removal of Dye Pollutants via Synergistic Adsorption and Degradation

Herein, for the first time, we report a “green”, one-pot reduction/decoration method for the synthesis of bifunctional adsorbent-catalytic hemin-graphene nanosheets by using a common available protein (bovine serum albumin, BSA) as both a reductant and a stabilizer. Our prepared nanosheets are highly stable and possess intrinsic peroxidase-like catalytic activity due to the decoration of BSA and hemin. Furthermore, benefiting from the combined advantages of graphene and BSA, these nanosheets are able to efficiently adsorb dye pollutants from aqueous solution. More importantly, due to their adsorption and catalytic ability, these adsorbent-catalytic nanosheets can be applied to highly efficient dye removal via synergistic adsorption and degradation. Specifically, our catalysts can easily bring organic dyes to their surface by adsorption, and then activate H₂O₂ to generate hydroxyl radicals, leading to the degradation of the dyes. Such catalytic mechanism of our as-prepared nanosheets was analogous to that of natural enzymes, in which the extremely high catalytic efficiency is largely dependent upon their ability to bring substrates in close proximity to the active sites of enzymes. Our finding may open new potential applications of hemin-graphene hybrid nanosheets in environmental chemistry, biotechnology, and medicine