| The use of self-assembled biomacromolecules in the nanostructuring of functionalinorganic-organic nanocomposites is one of the best lessons learned from nature.Bioinorganic material chemistry provides archetypes of strategies for the organization ofhierarchical interfacial materials. Bionanocomposite foams assembled from inorganicnanoparticles through the mediation of biological molecules (biomolecules) at nanoscalerepresent an emerging and intriguing area of research await to be exploited. Among thebiomolecules, bacterial cellulose (BC) has attracted considerable attention due to itssuperior mechanical properties in addition to its biocompatibility, biodegradability andrenewability. Here, we show that semiconductor nanocomposite materials with hierarchicalarchitectures can be organized by the mediation of bacterial cellulose. The nanocompositematerials have characteristic high porosity, low density and high specific surface areas. ZnOaerogel-like material with an intriguing interwoven hollow-sphere morphology exhibitsexcellent selective ethanol sensing property. ZnO/BC and ZnxCd1-xS/BC composite foamsexhibit excellent antibacterial properties and visible light photocatalytic H2productionproperties, respectively. Single crystalline ZnxCd1-xS/BC composite foam shows excellentphotocatalysis properties towards organic pollutants. All these could be a result offunctional integration of structural hierarchy, multiple interfaces and semiconductiveproperties.Detailed research works are summarized as following:1. Monolithic, flexible and porous zinc oxide/baterial cellulose bionanocompositefoams with a hierarchical architecture can be assembled through the mediation of bacterialcellulose. The assembly is achieved by controlled hydrolysis and solvothermal crystallization using a bacterial cellulose aerogel as a template in a non-aqueous polarmedium. The bionanocomposite foam is constructed of intimately packed spheres ofaggregated zinc oxide nanocrystals exhibiting a BET surface area of92m2g1. The zincoxide bionanocomposite foams show excellent antibacterial activity towards E.coli, whichgive them potential value as self-supporting wound dressing and water sterilizationmaterials.2. Zinc oxide aerogel-like materials with interconnected multimodal porosity andintriguing interwoven hollow-sphere morphology were generated from70wt%zincoxide/bacterial cellulose nanocomposite by controlled calcination. The monolithic zincoxide aerogellike materials with hierarchical porosity and high specific surface area exhibitexcellent selective ethanol sensing properties. ZnO-550generated by calcining ZnO/BC at aheating rate of2℃min-1to550℃exhibits excellent selective ethanol sensing propertiesas characterized by ultrafast response and recovery, high selectivity to ethanol and goodsensing stability. Our work offers a facile approach that may be applicable to the fabricationof a variety of inorganic aerogel like materials for enhanced functional performance.3. High visible-light photocatalytic H2production activity can be achieved byorganizing ZnxCd1-xS nanoparticles into the hierarchical architecture of bacterial cellulose.This is achieved by templated mineralization and ion exchange/seeded growth. Thebionanocomposite foams of ZnxCd1-xS/BC are flexible, monolithic and hierarchical porous.The optimized Zn0.09Cd0.91S/BC exhibits a high H2evolution rate of1450μmol h-1g-1andexcellent apparent quantum efficiency of12%at420nm. The monolithic nature ofZnxCd1-xS/BC makes catalyst recovery and recycling possible.4. Single crystalline ZnxCd1-xS nanosheets were mineralized through the mediation ofbacterial cellulose. Monolithic ZnxCd1-xS/bacterial cellulose nanocomposite (ZnxCd1-xS/BC)with high porosity, light weight and large surface-to-volume ration. The whole processeswere environmental friendly using water and ethanol as solvent at60-120℃. Zn0.10Cd0.90S/BC exhibits excellent visible-light photolysis to methylene blue (MB) with thedegradation rate reached to90%, and it also exhibits good stability and easy recycling. Thecurrent work manifests that the integration of intrinsic chemical properties with multilengthscale structural hierarchy affords performance optimization. |
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