Abstract
Innovative composites based on an amorphous-carbon matrix containing a second phase ZnO oxide and/or highly dispersed Zn metallic were synthesized via a modified Pechini route, in which a partial pyrolysis method was reached. Studies of adsorption in the dark and the photocatalytic activity for the cationic azo-dye, basic blue 41, and degradation were carried out. X-ray diffraction patterns for the carbon matrix and its composite with Zn show characteristics of the amorphous carbon. The infrared in the mid region of the composite prepared with ZnO and Zn exhibit vibrational bands related to bonds zinc oxide. The surface pH of the material is the main factor responsible for the adsorption of the azo-dye, but the contribution of mesopores favored the diffusion of molecules from the bulk of solution to the pore framework. Esters-like functional groups on the surface of carbons hinder the adsorption of the azo-dye. When Zn is embedded within amorphous carbon the photocatalytic activity of the composites showed up to 2.4 higher than neat ZnO. The enhancement in the photocatalytic activity and stability of C/ZnO/Zn and C/Zn composites is discussed in terms of a protector effect by the carbon layers inserted in composites. Carbon layers are responsible to inhibit the lixiviation of ZnO particles along irradiation.
Highlights
The environmental pollution is a global problem with a strong impact on the human health [1] and food security [2]
For a ion nanosized electrode carbon-based lithium-ion the contrary, presence both of large particles agglomerated in the form of plates ascribed to amorphous carbon and image of the C/zinc oxide (ZnO)/Zn composite (Figure 3c) shows the presence both of large particles agglomerated crystalline structures of smaller size ascribed to clusters of ZnO nanoparticles dispersed on the larger in the form of plates ascribed to amorphous carbon and crystalline structures of smaller size ascribed structures
As a matter of fact, these authors reported values for k1 and k2 in the same order magnitude than the results reported in the present work. It can be seen from the plots of the intraparticle diffusion model (IPD) for the C-amorphous, the C/Zn and C/ZnO/Zn samples in Figures S3c, S4c and S5c (Supplementary), respectively, that two steps are involved in the basic blue 41 (BB41) adsorption, described by the external mass transfer and intraparticle diffusion [62,63]
Summary
The environmental pollution is a global problem with a strong impact on the human health [1] and food security [2]. ZnO is a n-type semiconductor material with a high thermal conductivity, wide band gap (3.37 eV), that is able to generate charge carriers when stimulated with UVA light, biocompatible, and with a high natural abundance, and low-cost It has been reported [29,30] that ZnO is lixiviated in aqueous phase reactions even without.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
