Microstructurally Engineered Ceramics for Environmental …
515
microscopy (HRTEM) technique and selected area diffraction (SAED) pattern analysis. The surface area was evaluated by the BET method. The surface states were
identified by the fourier transformed infrared (FTIR) technique using KBr as an
internal reference standard (Das et al. 2017). Further, the X-ray photoelectron spectroscopy (XPS) technique was also used to identify the surface oxidation states.
Both the initial concentration, C(I) of the Cu(II) solutions, e.g., S1 (~80 mg L
−1 ),
S2 (~95 mg L
−1 ), S3 (~100 mg L
−1 ), S4 (~140 mg L
−1 ), and S5 (~920 mg L
−1 ) and
the corresponding MHNPL samples treated final solution concentrations, C(F); were
determined by the inductively coupled plasma atomic emission spectroscopy (ICPAES) technique (Das et al. 2017). For MB dye degradation efficacy examination, the
DMHNPLA was synthesized in a similar manner as described in (Das et al. 2017) but
with a specialized sonication technique (Das et al. 2018) to make the structure more
porous. The characterization techniques were almost similar to those reported earlier
(Das et al. 2017). In addition, the direct bandgap (E g ) energy values were evaluated
by using the diffuse reflectance measurements from the UV-Vis spectra (Das et al.
2018). Thus, for both control MB dye solution and DMHNPLA samples treated MB
dye solutions (volume −50 cc, concentration −4.6 mg L
−1 ) the optical properties in
the range 200–800 nm were recorded by the calibrated UV-Vis technique (Das et al.
2018). Prior to addition of about 10 mg Mg(OH) 2 powders the MB dye solutions
were preserved in dark (Das et al. 2018). Following the addition, the solutions were
exposed for 60, 90, 120, 150, and 180 min to direct sunlight. Further details of both
synthesis and characterizations are reported by us elsewhere (Das et al. 2017, 2018).
3 Results and Discussions
3.1 MHNPL Nano-Adsorbent
3.1.1 XRD Studies
A comparison of the XRD patterns of MHNPL (Fig. 1a) and CAMHNPL (Fig. 1b),
respectively, confirms that pure hexagonal brucite phase (ICSD Code: 31053) occurs
in MHNPL and that it adsorbs Cu(II) ions in its structure. The monoclinic copper
nitrate hydroxide [Cu 2 (NO 3 )(OH) 3 ] (ICSD Code: 31353) is, therefore, present as a
minor phase in Fig. 1b.
3.1.2 Pore Size and Surface Area
Based on N 2 adsorption and desorption data and BET measurement data published
elsewhere (Das et al. 2017, 2018), the characteristic pore size details along with
the data on isotherm type and BET surface area are given in Table 4. These data
match with those from the literature (Yu et al. 2004). Further, MHNPL samples have
515
microscopy (HRTEM) technique and selected area diffraction (SAED) pattern analysis. The surface area was evaluated by the BET method. The surface states were
identified by the fourier transformed infrared (FTIR) technique using KBr as an
internal reference standard (Das et al. 2017). Further, the X-ray photoelectron spectroscopy (XPS) technique was also used to identify the surface oxidation states.
Both the initial concentration, C(I) of the Cu(II) solutions, e.g., S1 (~80 mg L
−1 ),
S2 (~95 mg L
−1 ), S3 (~100 mg L
−1 ), S4 (~140 mg L
−1 ), and S5 (~920 mg L
−1 ) and
the corresponding MHNPL samples treated final solution concentrations, C(F); were
determined by the inductively coupled plasma atomic emission spectroscopy (ICPAES) technique (Das et al. 2017). For MB dye degradation efficacy examination, the
DMHNPLA was synthesized in a similar manner as described in (Das et al. 2017) but
with a specialized sonication technique (Das et al. 2018) to make the structure more
porous. The characterization techniques were almost similar to those reported earlier
(Das et al. 2017). In addition, the direct bandgap (E g ) energy values were evaluated
by using the diffuse reflectance measurements from the UV-Vis spectra (Das et al.
2018). Thus, for both control MB dye solution and DMHNPLA samples treated MB
dye solutions (volume −50 cc, concentration −4.6 mg L
−1 ) the optical properties in
the range 200–800 nm were recorded by the calibrated UV-Vis technique (Das et al.
2018). Prior to addition of about 10 mg Mg(OH) 2 powders the MB dye solutions
were preserved in dark (Das et al. 2018). Following the addition, the solutions were
exposed for 60, 90, 120, 150, and 180 min to direct sunlight. Further details of both
synthesis and characterizations are reported by us elsewhere (Das et al. 2017, 2018).
3 Results and Discussions
3.1 MHNPL Nano-Adsorbent
3.1.1 XRD Studies
A comparison of the XRD patterns of MHNPL (Fig. 1a) and CAMHNPL (Fig. 1b),
respectively, confirms that pure hexagonal brucite phase (ICSD Code: 31053) occurs
in MHNPL and that it adsorbs Cu(II) ions in its structure. The monoclinic copper
nitrate hydroxide [Cu 2 (NO 3 )(OH) 3 ] (ICSD Code: 31353) is, therefore, present as a
minor phase in Fig. 1b.
3.1.2 Pore Size and Surface Area
Based on N 2 adsorption and desorption data and BET measurement data published
elsewhere (Das et al. 2017, 2018), the characteristic pore size details along with
the data on isotherm type and BET surface area are given in Table 4. These data
match with those from the literature (Yu et al. 2004). Further, MHNPL samples have