Borohydride-Assisted Surface Activation of CoO/CoFeO Composite and Its Catalytic Activity for 4-Nitrophenol Reduction.

Surface activation of catalysts is known to be an efficient process to enhance their activity in catalytic processes. The activation process includes the generation of oxygen vacancies, changing the nature of the catalyst surface from acidic to basic and vice versa, and the reduction of catalyst surface by H. On the other hand, magnetically separable catalysts are highly beneficial for their utilization in water or biological fluid-based catalytic processes, as they can be easily guided to the target site and recovered.

Structural, Magnetic, and Catalytic Evaluation of Spinel Co, Ni, and Co-Ni Ferrite Nanoparticles Fabricated by Low-Temperature Solution Combustion Process.

Here, we present the low-temperature (∼600 °C) solution combustion method for the fabrication of CoFeO, NiFeO, and CoNiFeO nanoparticles (NPs) of 12-64 nm range in pure cubic spinel structure, by adjusting the oxidant (nitrate ions)/reductant (glycine) ratio in the reaction mixture. Although nitrate ions/glycine (N/G) ratios of 3 and 6 were used for the synthesis, phase-pure NPs could be obtained only for the N/G ratio of 6. For the N/G ratio 3, certain amount of Ni cations was reduced to metallic nickel.

Effects of Oxidizing/Reducing Agent Ratio on Phase Purity, Crystallinity, and Magnetic Behavior of Solution-Combustion-Grown BiFeO Submicroparticles.

Fabrication of phase-pure well-crystalline BiFeO submicroparticles in large scale is of great importance for the utilization of this rhombohedrally distorted perovskite material in applications such as memory storage and spintronic devices and visible photocatalyst for the degradation of organic pollutants. In fact, because of the narrow temperature range of phase stabilization, the fabrication of phase-pure BiFeO in large scale remained elusive. We present the synthesis of phase-pure BiFeO particles of submicrometric dimensions (246-330 nm average size) through the adjustment of oxidizing/reducing agent ratio in solution combustion process utilizing glycine as reducing agent and nitrate precursors as oxidizing agent.

Bismuth Oxide Nanoparticles Partially Substituted with Eu, Mn, and Si: Structural, Spectroscopic, and Optical Findings.

Interest in nanostructured partially substituted bismuth oxides has been increasing over the last years. Research on new synthesis methods, properties, and possible uses for these oxides is needed. The objective of this paper is to synthesize β-BiO, β-BiO:Eu, β-BiO:Mn, BiBiO, BiBiO/Li, BiMnO, and BiSiO nanoparticles and to investigate their structural, spectroscopic, and optical changes.

Easy synthesis of high-purity BiFeO3 nanoparticles: new insights derived from the structural, optical, and magnetic characterization.

Synthesis of high-purity BiFeO3 is very important for practical applications. This task has been very challenging for the scientific community because nonstoichiometric Bi(x)Fe(y)O(z) species typically appear as byproducts in most of the synthesis routes. In the present work, we outline the synthesis of BiFeO3 nanostructures by a combustion reaction, employing tartaric acid or glycine as promoter.