Naslov
Synthesis and Properties of Ni-doped Goethite and Ni-doped Hematite Nanorods

Autori
Krehula, Stjepko ; Ristić, Mira ; Mitar, Ivana ; Wu, Chuchu ; Li, Xuning ; Jiang, Luhua ; Wang, Junhu ; Sun, Gongquan ; Zhang, Tao ; Perović, Marija ; Bošković, Marko ; Antić, Bratislav ; Musić, Svetozar

Izvornik
Croatica chemica acta (0011-1643) 91 (2018), 3; 389-401

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
α-FeOOH ; α-Fe2O3 ; Ni doping ; XRPD ; Mössbauer spectroscopy ; FE-SEM ; OER

Sažetak
Ni-doped goethite (α-FeOOH) nanorods were synthesized from mixed Fe(III)-Ni(II) nitrate solutions with various Ni/(Ni+Fe) ratios (0, 5, 10, 20, 33 and 50 mol % Ni) by hydrothermal precipitation in a highly alkaline medium using the strong organic alkali, tetramethyl¬ammonium hydroxide (TMAH). Ni-doped hematite (α-Fe2O3) nanorods were obtained by calcination of Ni- doped goethite nanorods at 400 °C. The Ni2+- for-Fe3+ substitution in goethite and hematite was confirmed by determination of the unit cell expansion (due to the difference in the ionic radii of Fe3+ and Ni2+) using XRPD and determination of the reduction of a hyperfine magnetic field (due to the difference in magnetic moments of Fe3+ and Ni2+) using Mössbauer spectroscopy. Single- phase goethite nanorods were found in samples containing 0 or 5 mol % Ni. A higher Ni content in the precipitation system (10 mol % or more) resulted in a higher Ni2+-for-Fe3+ substitution in goethite, and larger Ni-doped goethite nanorods, though with the presence of low crystalline Ni-containing ferrihydrite and Ni ferrite (NiFe2O4) as additional phases. Significant changes in FT-IR and UV-Vis-NIR spectra of prepared samples were observed with increasing Ni content. Electrochemical measurements of samples showed a strong increase in oxygen evolution reaction (OER) electrocatalytic activity with increasing Ni content.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA