Structure and photoluminescence characteristics of mixed nickel–chromium oxides nanostructures

In this work, nickel–chromium-layered double hydroxide (Ni(II)–Cr(III)LDH) is prepared via co-precipitation method at room temperature with 1:2:3 molar ratio of CrCl 3 ·6H 2 O: NiCl 2 ·6H 2 O: NaCl using sodium hydroxide as a precipitating agent. Ni(II)–Cr(III) LDH is synthesized in the absence and in the presence of functionalized amino-organic compounds such as acetamide, glycine, and urea. The ratio between CrCl 3 ·6H 2 O: NiCl 2 ·6H 2 O: NaCl: acetamide, glycine or urea was 1:2:3:6. The mixed nickel–chromium oxide nanoparticles are prepared by the calcination of Ni(II)–Cr(III) LDHs at 600 ℃ for 2.5 h. Ni(II)–Cr(III) LDHs and mixed Ni(II)–Cr(III) oxides nanoparticles are characterized by several techniques including FTIR, TGA, XRD, FESEM, HRTEM, and PL. Functionalized amino-organic compounds improve the thermal stability in the order of glycine > urea > acetamide. Also, it affects photoluminescence PL intensity which indicates a marked reduction in electron–hole recombination with the highest photocatalytic activity compared to visible light-driven H 2 and O 2 evolution. The resulting mixed Ni(II)–Cr(III) oxides particles have an amorphous structure and a relatively uniform size of below 10 nm. Graphic abstract