Investigation of uranium oxide hydrates with barium(ii) ions: structural diversity, uranium valences and implications

Abstract

Although barium(II) ions play an important role in the natural weathering of the mineral uraninite (UO2+x) and are expected to therefore do the same for spent nuclear fuel in geological...

Capturing ammonium nitrate in a synthetic uranium oxide hydrate phase: revealing the role of ammonium ions and anion inclusions

“…11 In terms of secondary cations for the synthetic UOH materials, alkali and alkaline earth metal ions dominate. 12–18 However, UOHs with transition metals, 19–22 lead 23 and lanthanide ions 24–26 have also been studied and reported recently.…”

“…Typical examples include complicated 3D architectures of UOH materials stabilized by Cs( i ), Sr( ii ) and Ba( ii ) ions. 16,17,27 Furthermore, open framework structures known as uranium oxide hydrate frameworks (UOHFs) can be formed with uranyl pentagonal bipyramid dimers acting as bridging ligands linking the β-U 3 O 8 type uranium oxide hydroxide layers. 28 These UOHFs have high structure flexibility and are capable of incorporating a range of additional cations from 1+ to 4+ valences including (NH 4 ) + , Sr 2+ , Y 3+ , Er 3+ , Sm 3+ , Eu 3+ , Gd 3+ and U 4+ in the framework channels, 29–32 highlighting the complex uranium hydrolysis chemistry in the presence of various secondary cations.…”

Filling the gaps of uranium oxide hydrates with magnesium(ii) ions: unique layered structures and the role of additional sodium(i) ions

“…[19][20][21][22] In addition, the uranyl oxide hydroxide layer topologies for various UOH minerals have been comprehensively reviewed. 23 In addition, synthetic UOH materials with a wide range of secondary cations including alkali, 24,25 alkaline earth, [26][27][28][29] lead, 30 transition metals [31][32][33] and lanthanide ions [34][35][36] have been reported. Furthermore, synthetic UOH phases with interlayer anions are also possible, although less studied.…”