Construction of heterostructured g-C3N4/ZnO/cellulose and its antibacterial activity: experimental and theoretical investigations.

A g-C3N4/ZnO/cellulose ternary composite (labeled as CNZCel) with an ordered structure and excellent antibacterial properties has been successfully synthesized via a facile method. Its morphology, microstructure and components have been analyzed by using XRD, SEM, TEM and EDS, and the results corroborate the co-existence of three components in the ternary composite. It is revealed that ZnO particles are connected to the layered g-C3N4 and simultaneously attached to the cellulose substrate. This microstructural feature is also borne out by the relativistic density functional study of a finite g-C3N4-ZnO-cellulose cluster. Both experimental and theoretical results unravel that the interfacial bonding interactions in the ternary composite improve electron transfer among components and enable high-efficiency spatial separation of photogenerated electrons and holes. Consequently, good antibacterial performance of the composite has been found in tests. This study provides the prospect of preparing low-cost and environment-friendly food packaging materials, which are also endowed with excellent antibacterial activity.

Cellulose nanofiber induced self-assembly of zinc oxide nanoparticles: Theoretical and experimental study on interfacial interaction.

In-depth understanding of interfacial behavior between biopolymer and semiconductor metal oxides is crucial to developing potential applications of their composites. A structure-ordered cellulose/zinc oxide composite was synthesized and systematically examined by a relativistic density functional theory. The prepared composite shows a hierarchical structure. ZnO nanoparticles of around 30 nm in size are found to uniformly grow along the cellulose fiber, which together construct the primary-structure unit. Associated with experimental characterizations, calculations unravel that the electrostatic attraction between cellulose and ZnO is the main driving force to form the primary structure and the subsequent electron transfer from cellulose to ZnO enhances their interfacial interaction; moreover, an exothermic process was computed. The interfacial interaction is mainly contributed by Zn-Oc (Oc denotes the cellulose oxygen atom), which is intrinsically of a dative bond; the interaction was calculated between -1.39 and -1.83 eV in strength and dominated by orbital attractions.