Discovery of Amorphous Iron Hydrides via Novel Quiescent Reaction in Aqueous Solution.

ABSTRACT: Novel amorphous iron hydrides (AIHs) are synthesized for the first time under ambient conditions by employing novel "quiescent reaction", without stirring for mixing solutions, during a conventional aqueous reduction-precipitation process. The kind and morphology of AIHs are dependent on the processing condition, where two types are found, with one form consisting of a tangle of uniform nanowires and the other being granular in nature. Both AIHs undergo transformation to crystalline ?-Fe by heat treatment at 600?°C. The nanowire AIH exhibits the hydrogen content of 0.10?wt%, while the granular AIH of 0.22?wt%. Their magnetic and thermal properties are accordingly different, and the non-diffusive hydrogen contributes to stability of AIHs. It is strongly suggested that, by use of quiescent reaction, iron-hydrogen clusters are formed and preserved at an early stage of precipitation reaction, and subsequently aggregated into novel AIHs, preventing ?-Fe crystallization. Hence, the AIHs would be categorized as metastable hydrides stabilized with iron-hydrogen clusters. In addition, newly discovered quiescent reaction in aqueous solution, from which unprecedented AIHs are derived, sheds new light on fundamental and essential aqueous reaction.

SUBMITTER: Taguchi K 

PROVIDER: S-EPMC7148363 | biostudies-literature | 2020 Apr

REPOSITORIES: biostudies-literature