1 3
Topics in Current Chemistry (2020) 378:3
highlighted involved the preparation of a ZnO/diatomite hybrid photocatalyst. Precursors of the obtained materials came from industrial waste. Zn dust waste from
a hot-dip galvanizing process was used as ZnO precursor, while diatomite waste
derived from breweries was used as porous substrate (Fig. 3a). In a typical experiment, a Zn salt solution was prepared by dissolving the Zn dust in a nitric acid
solution. The final ZnO/diatomite was prepared by a simple impregnation method
followed by calcination treatment at 400–700 °C. The sample codes (see XRD in
Fig. 3g) were ZD-1, ZD-2, ZD-3, and ZD-4 for diatomite loaded with 10, 20, 30,
and 40% of the oxide semiconductor, respectively. A clear decrease in BET surface
area was observed with an increase in the amount of ZnO, which was attributed to
pore blocking due to the incorporation of ZnO particles in the porous support [63].
The highest efficiency for degradation of the MB solution was obtained using the
ZD-2 sample photocatalyst loaded with 20 wt% ZnO (Fig. 3h).
4 Sulfide‑based Materials: S from Waste
Sulfides have also been proposed as suitable photocatalysts in several reactions [5].
In particular, transition-metal sulfides such as CdS or ZnS have been documented
as photocatalysts. Additionally, Cu 2 S, CdS, In 2 S 3 , WS 2 , and MoS 2 , as well as more
complex structures such as ZnIn 2 S 4 , CdIn 2 S 4 , and CdLa 2 S ternary systems, have
shown a photocatalytic response [64]. Like those previously described for oxide
materials, there are several options for metallic waste valorization during the synthesis of sulfides. However, unlike metallic oxide, in which the final production of
the oxide can be easily achieved by calcination in air, a sulfur source is necessary to
produce the corresponding sulfides. The extraction of S-containing mining residues
Fig. 3 a, b Transmission electron microscopy (TEM) images of PETZ 1.0 and photodegradation of MB
using the synthesized samples [62]. d–f Scanning electron microscopy (SEM) images of ZD-1, ZD-3,
and ZD-4 samples. X-ray diffraction (XRD) spectra of ZD-X samples and ZnO reference sample. h Photodegradation results for samples and references [63]
7
Reprinted from the journal
Topics in Current Chemistry (2020) 378:3
highlighted involved the preparation of a ZnO/diatomite hybrid photocatalyst. Precursors of the obtained materials came from industrial waste. Zn dust waste from
a hot-dip galvanizing process was used as ZnO precursor, while diatomite waste
derived from breweries was used as porous substrate (Fig. 3a). In a typical experiment, a Zn salt solution was prepared by dissolving the Zn dust in a nitric acid
solution. The final ZnO/diatomite was prepared by a simple impregnation method
followed by calcination treatment at 400–700 °C. The sample codes (see XRD in
Fig. 3g) were ZD-1, ZD-2, ZD-3, and ZD-4 for diatomite loaded with 10, 20, 30,
and 40% of the oxide semiconductor, respectively. A clear decrease in BET surface
area was observed with an increase in the amount of ZnO, which was attributed to
pore blocking due to the incorporation of ZnO particles in the porous support [63].
The highest efficiency for degradation of the MB solution was obtained using the
ZD-2 sample photocatalyst loaded with 20 wt% ZnO (Fig. 3h).
4 Sulfide‑based Materials: S from Waste
Sulfides have also been proposed as suitable photocatalysts in several reactions [5].
In particular, transition-metal sulfides such as CdS or ZnS have been documented
as photocatalysts. Additionally, Cu 2 S, CdS, In 2 S 3 , WS 2 , and MoS 2 , as well as more
complex structures such as ZnIn 2 S 4 , CdIn 2 S 4 , and CdLa 2 S ternary systems, have
shown a photocatalytic response [64]. Like those previously described for oxide
materials, there are several options for metallic waste valorization during the synthesis of sulfides. However, unlike metallic oxide, in which the final production of
the oxide can be easily achieved by calcination in air, a sulfur source is necessary to
produce the corresponding sulfides. The extraction of S-containing mining residues
Fig. 3 a, b Transmission electron microscopy (TEM) images of PETZ 1.0 and photodegradation of MB
using the synthesized samples [62]. d–f Scanning electron microscopy (SEM) images of ZD-1, ZD-3,
and ZD-4 samples. X-ray diffraction (XRD) spectra of ZD-X samples and ZnO reference sample. h Photodegradation results for samples and references [63]
7
Reprinted from the journal