Contribution of TEMPO-Oxidized Cellulose Gel in the Formation of Flower-Like Zinc Oxide Superstructures: Characterization of the TOCgel/ZnO Composite Films

Abstract

Abstract:In the present paper, we report on a simple and new approach for the synthesis of hierarchical flower-like zinc oxide superstructures ZnO (FL) in the presence of the TEMPO-oxidized cellulose gel (TOCgel) through a room temperature sol-gel process in aqueous medium. Resulting composite films based on TOCgel and ZnO were investigated by several techniques including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA) and mechanical tests. SEM images demonstrated the formation of well-shaped flower-like ZnO superstructures within the fibrous structure of the TOCgel with a uniform diameter (~5 μm). FTIR and XPS results clearly confirmed the formation of such ZnO structures. We suggested that the carboxylate groups of TOCgel fibers act as capping agents and promote the construction of such flower-like ZnO via a nucleation-growth process. A proposed mechanism based on the oriented attachment-driven growth was discussed in order to explain the formation of ZnO (FL). The photocatalytic activity of the TOCgel/ZnO composite in the degradation of methylene blue (MB) under UV irradiation was clearly confirmed. Finally, mechanical tests demonstrated that the former TOCgel/ZnO film maintained a good flexibility (bent up to ~120°) without losing its photocatalytic activity.

Effect of Zn Content on the physicochemical Characteristics and Photoactivity of ZnO supported Activated Carbon

“…Hence the light absorption and charge separation were significantly enhanced. The same trend was reported in the synthesis of ZnO nanocomposites 14 . As effect of the formation of different particle size of ZnO, multiple band gap values are found for ZnO/AC-7.5 and ZnO/AC-10.0 (Table 1).…”

Mesoporous Carbon Microfibers for Electroactive Materials Derived from Lignocellulose Nanofibrils

“… 46 Then, polymer decomposition and chain scission start (hemicellulose ∼200–315 °C, cellulose ∼315–400 °C, and lignin ∼160–600 °C), 47 followed by carbonization until 900 °C. 48 The degradation and pyrolysis behavior of the microfibers were slightly different depending on their composition, Figure 4 . Pure TOCNF microfibers started to decompose ( T onset ) at 230 °C.…”

“…Then, polymer decomposition and chain scission started (hemicelluloses ~ 200-315 °C, cellulose ~ 315-400 °C and lignin ~ 160-600 °C) (Lin and Chen 2015). Finally, carbonization occurred until 900 ℃ (Jradi et al 2015). In general, fibres containing higher lignin or LCNF content possessed better thermal stability ( Table 3).…”

Preparation of ternary ZnO/Ag/cellulose and its enhanced photocatalytic degradation property on phenol and benzene in VOCs

“…The binding energies at 368.0 eV and 374.1 eV are corresponding to Ag3d 5/2 and Ag3d 3/2 in Figure 4c [39,40]. The binding energies of Zn 2p 3/2 and Zn 2p 1/2 is shown in Figure 4d, which determined to be 1021.5 eV and 1044.5 eV, and the peak separation distance between them was 23.0 eV [41]. The XPS gives the evidence that ZAC composite has been successfully prepared by our method.…”