Nat Mater. 2012 Apr 15;11(6):507-11. doi: 10.1038/nmat3302.
In oxides, the substitution of non-oxide anions (F(-),S(2-),N(3-) and so on) for oxide introduces many properties, but the least commonly encountered substitution is where the hydride anion (H(-)) replaces oxygen to form an oxyhydride. Only a handful of oxyhydrides have been reported, mainly with electropositive main group elements or as layered cobalt oxides with unusually low oxidation states. Here, we present an oxyhydride of the perhaps most well-known perovskite, BaTiO(3), as an O(2-)/H(-) solid solution with hydride concentrations up to 20% of the anion sites. BaTiO(3-x)H(x) is electronically conducting, and stable in air and water at ambient conditions. Furthermore, the hydride species is exchangeable with hydrogen gas at 400 °C. Such an exchange implies diffusion of hydride, and interesting diffusion mechanisms specific to hydrogen may be at play. Moreover, such a labile anion in an oxide framework should be useful in further expanding the mixed-anion chemistry of the solid state.
在氧化物中，非氧化物阴离子（F(-)、S(2-)、N(3-) 等）取代氧化物会引入许多性质，但最不常见的取代是氢阴离子（H(-)）取代氧形成氢氧化物。只有少数氢氧化物被报道过，主要是与正电性主族元素形成的，或者是具有异常低氧化态的层状钴氧化物。在这里，我们展示了一种可能是最著名的钙钛矿 BaTiO(3)的氢氧化物，它是 O(2-)/H(-)的固溶体，其中氢化物的浓度高达阴离子位的 20%。BaTiO(3-x)H(x) 是电子导体，在空气和水中在环境条件下稳定。此外，氢化物在 400°C 时可与氢气进行交换。这种交换意味着氢化物的扩散，并且可能涉及到特定于氢的有趣扩散机制。此外，氧化物骨架中如此不稳定的阴离子在进一步扩展固态混合阴离子化学方面应该是有用的。
