Preparation of new bio-based chitosan/Fe2O3/NiFe2O4 as an efficient removal of methyl green from aqueous solution

Constructing S‐scheme heterojunctions with tunable interfacial oxygen vacancy via UiO‐66‐NH2‐derived ZrO2‐x for efficient photocatalytic performance

“…29 In the FT-IR spectrum of α-Fe 2 O 3 , the sharp peaks at 525 cm À1 and 450 cm À1 correspond to the stretching vibrations of Fe-O bonds. 21,30 As shown in Figure S1, the FT-IR spectra of the composite materials exhibit characteristic peaks of both components. Furthermore, with the increase in α-Fe 2 O 3 content, the peak at 450 cm À1 in the composite materials shifts to higher wavenumbers.…”

New chitosan modified with epichlohydrin and bidentate Schiff base applied to removal of Pb2+ and Cd2+ ions

“…Chitosan shows two broad peaks at about 10 and 24 . [49][50][51][52][53][54][55] As seen in Figure 2, the peaks at 10.02 and 23.84 are assigned to chitosan, while peaks at 13.27 and 28.27 may be assigned to the modification of chitosan using epichlorohydrin and 2-pyridinecarboxaldehyde and preparation of new groups (C O C and C N ) in ECH/CS/2PCA. Finally, the low intensity of peaks indicates that the modified chitosan ECH/CS/2PCA has a less crystalline structure than pure chitosan due to the formation of hydrogen bonds with new groups, and the possibility of crystal formation is reduced.…”

“…There is an endothermic peak at 82 C corresponding to evaporation of the solvent and a sharp exothermic peak at 258 C correspondence to the major thermal decomposition of the pyranose chain of chitosan. [49][50][51][52][53][54][55] After recovery of CEP from Pb(II) and Cd(II) solution, we recorded DSC curves of them that are depicted in Figure 3b,c, respectively. The peak corresponding to solvent evaporation, not changed (80 and 79 C), while the peak corresponding to pyranose chain decomposition appeared at higher temperatures (275 and 278 C), confirming the loaded of Pb(II) and Cd(II) on the surface of CEP, that is confirmed by changing of surface morphology of CEP after recovery from Pb(II) and Cd(II) solution (Figure 4).…”

“…Pure chitosan has a smooth and dense surface, [10,14,17] while modified chitosan almost has a rough surface, [10,14,[49][50][51][52][53][54][55] due to the preparation of pendant Schiff base groups on the polymeric chain of chitosan. SEM images of CEP, Pb(II), and Cd(II) loaded on the surface of CEP was shown in Figure 4.…”

Fabrication of a pH-responsive magnetic nanocarrier based on carboxymethyl cellulose-aminated graphene oxide for loading and in-vitro release of curcumin

“…According to the zeta potential results, the pHpzc of CoFe2O4/GO-ADH-CMC was estimated to be 2.9 (Fig. 5 (b)), implying that at pH < 2.9, the surface of the adsorbent was positively charged, and negatively charged at pH > 2.9 [41]. The small value of the point of zero charge (pzc) for the adsorbent may be assigned to the presence of abundant oxygenated functional groups (such as hydroxyl, carboxyl, and carbonyl groups of CMC biopolymer and GO nanosheets) on the adsorbent surface [42].…”