Insight into the photocatalytic properties of diatomite@Ni/NiO composite for effective photo-degradation of malachite green dye and photo-reduction of Cr (VI) under visible light.
J Environ Manage
; 254: 109799, 2020 Jan 15.
Article
en En
| MEDLINE
| ID: mdl-31710977
ABSTRACT
Diatomite frustules decorated by nano Ni/NiO nanoparticles (Diatomite@Ni/NiO) were synthesized as a novel photocatalyst for effective degradation of malachite green cationic dye (M.G) and photocatalytic-reduction of Cr (VI) ions. The composite was characterized by different analytical techniques and revealed enhancing in the surface area (400â¯m2/g), 5.8â¯nm as average pore diameter and showed lower band gap energy (1.71â¯eV) than NiO as single phase. The photocatalytic activity of the composite in the removal of M.G and reduction of Cr (VI) was evaluated under visible light considering the pH, illumination time, catalyst mass, and the pollutants concentrations. The results revealed complete removal of 25â¯mg/L M.G can be achieved using 20â¯mg, 30â¯mg, 40â¯mg and 50â¯mg of the after 150â¯min, 90â¯min, 60â¯min, and 30â¯min, respectively. The complete degradation of 50â¯mg/L can be obtained after 240â¯min, 90â¯min, and 60â¯min using 20â¯mg, 40â¯mg, and 50â¯mg of the catalyst, respectively. This also was reported for the photocatlytic-reduction of 25â¯mg/L of Cr(VI) ions as the complete reduction was estimated after 180â¯min, 60â¯min and 30â¯min using 20â¯mg, 40â¯mg, and 50â¯mg, respectively. Also, 50â¯mg/L of Cr (VI) can be completely reduced after 240â¯min, 90â¯min, and 60â¯min using 20â¯mg, 40â¯mg, and 50â¯mg as catalyst dosage, respectively. The photocatalytic degradation of M.G controlled mainly by the generated electron-hole pairs and the superoxide species while the photocatalytic-reduction of Cr (VI) controlled mainly by the directly excited electrons of Ni/NiO and partially by the formed superoxide radicals. Hence, the synthetic diatomite@Ni/NiO composite can be considered as potential photocatalyst in the degradation of M.G dye and photoreduction of Cr (VI) ions.
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MEDLINE
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Cromo
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Tierra de Diatomeas
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En
Año:
2020
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Article