A Fe3O4@SiO2@graphene quantum dot core-shell structured nanomaterial as a fluorescent probe and for magnetic removal of mercury(II) ion

NIR‐responsive Fe3O4@PPy nanocomposite for efficient potential use in photothermal therapy

“…[40,[51][52][53] In the FTIR spectra of Fe 3 O 4 NPs, and Fe 3 O 4 @PPy nanocomposite samples, it was determined that Fe 3 O 4 @PPy nanocomposite structure had characteristic Fe O band peak (580 cm −1 ) corresponding to Fe 3 O 4 NPs. [36,54] Additionally, the presence of Fe O band with all the characteristic bands, which belongs to PPy polymeric structure in the FTIR spectra of binary Fe 3 O 4 @PPy nanocomposite illustrated that Fe 3 O 4 NPs are coated by the polymeric structure in accordance with UV-vis analysis. [54,55] The superparamagnetic properties of Fe 3 O 4 and binary Fe 3 O 4 @PPy nanocomposite with zero coercive field were examined by VSM analysis (Figure 3a).…”

“…The first step was preparing Fe 3 O 4 NPs by co-precipitation approach using aqueous solution of Fe 2+ (FeCl 2 .4H 2 O) and Fe 3+ (FeCl 3 .6H 2 O) chlorides with 1:2 M ratio, then adding an alkaline solution (NH 3 ) while mechanically stirring at 80 C under N 2 atmosphere in an oil bath. [36] In the second step, the surfaces of Fe 3 O 4 NPs was coated with PPy via in situ polymerization of pyrrole in the water-methanol medium where PVA and SDBS undertook stabilizer and emulsifier roles, respectively. [31] 3 mg ml −1 of PVA solution was stirred at 75 C for 2 hr and at room temperature for another 2 hr.…”

Experimental study and modelling of effective parameters on removal of Cd(II) from water by halloysite/graphene quantum dots magnetic nanocomposite as an adsorbent using response surface methodology

“… 35 The broad peak appeared in the range of 3350–3440 cm −1 resulting from the participation of the vibrational signals of the hydroxyl (‐OH) and amine (‐NH 2 ) groups in the APTES sections 32 . The absorption bands observed at 1576.18 and 1625.88 cm −1 , correlated to bending vibration of C = C and stretching vibration of C = O respectively, which is a strong reason for the presence of GQDs on the nano‐composite surface 34 . All the above observations point to the proper construction of NiFe 2 O 4 /HNTs/GQDs.…”

“…This recommends that the APTES link to NiFe 2 O 4 ‐HNTs did not change its crystallinity. Also, in the NiFe 2 O 4 /HNTs/GQDs diffraction pattern, no sign of identifying GQDs, which may be the result of their low amounts, high dispersions and low crystallinity of GQDs in NiFe 2 O 4 /HNTs/GQDs nanocomposites 32, 34 …”

Adsorptive removal of cadmium from aqueous solutions using NiFe2O4/hydroxyapatite/graphene quantum dots as a novel nano-adsorbent

“…Moreover, the peak located at 3100 cm −1 in spectrum indicates the asymmetric stretching and symmetric vibrations of C-H. The occurrence of the C=C bending vibrations peak at 1574 cm −1 and C=O stretching vibration band at 1668 cm −1 gives a strong proof of GQDs and synthesis of NiFe 2 O 4 /HAP/GQDs [31].…”