Improved homogeneity of tunnel size in Na-stabilized 2 × 3 and 2 × 4 MnO₂ structures was achieved by identifying and controlling critical synthesis parameters. 2 × 3 and 2 × 4 MnO₂ tunnel manganese oxide nanowires were obtained by hydrothermal treatment of Na-birnessite, a layered manganese oxide that undergoes a layer-to-tunnel transition under high pressure and temperature. Herein, the improved ordering of [MnO₆] octahedra is revealed via a combined analysis of X-ray diffraction patterns and scanning transmission electron microscopy images. We show that crystallinity of the Na-birnessite precursor and the chemical composition of the system during hydrothermal treatment are crucial for achieving the targeted size of the structural tunnels with adequate uniformity.

通过确定和控制关键的合成参数，可以改善Na稳定的2 × 3和2 × 4 MnO ₂结构中隧道尺寸的均匀性。通过对钠水钠锰矿进行水热处理，获得了2 × 3和2 × 4 MnO ₂隧道氧化锰纳米线，钠水钠锰矿是在高压和高温下经历层-隧道过渡的层状锰氧化物。此处，[MnO _6的有序化通过八面体X射线衍射图谱分析和扫描透射电子显微镜图像的组合揭示八面体。我们表明钠水钠锰矿前体的结晶度和水热处理期间系统的化学组成对于实现具有足够均匀性的结构隧道的目标尺寸至关重要。