Abstract The present study combines the advantages of chemical exfoliation and elemental doping to have enhanced surface area, better charge carrier separation and extended light absorption in N3−/Nb4+ co-doped nanosheets, which were employed for the first time to study their O2 evolution response. The Dion-Jacobson phase, KCa2NaNb4O13 perovskite was calcined under NH3 environment at various reaction durations (5 hr, 6 hr, 7 hr) to yield N3−/Nb4+ co-doped layered structures and subsequently exfoliated into ultrathin nanosheets. The N3−/Nb4+ co-doped nanosheets realized superior visible light absorption and bandgap narrowing as determined from UV–visible spectroscopy profiles. The synthesis of bulk materials and ultrathin morphology of exfoliated nanosheets were confirmed through XRD, SEM and AFM. The chemical states of the elements were examined by XPS measurements. The optimized N3−/Nb4+ co-doped CNNO--6hr nanosheets demonstrated excellent O2 evolution of 903 μmol g-1 after 4 h compared to N3−/Nb4+ co-doped CNNO--5hr (510 μmol g-1), N3−/Nb4+ co-doped CNNO--7hr (528 μmol g-1) and non-doped CNNO- nanosheets (381 μmol g-1). Our study paves a way on the feasibility of combining various chemical strategies for advanced photocatalyst design.

中文翻译：

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用于光催化水氧化的氮掺杂超薄钙/铌酸钙钛矿纳米片

摘要 本研究结合化学剥离和元素掺杂的优点，在 N3−/Nb4+ 共掺杂纳米片中具有增强的表面积、更好的电荷载流子分离和扩展的光吸收，首次用于研究它们的 O2 演化响应。 . Dion-Jacobson 相 KCa2NaNb4O13 钙钛矿在 NH3 环境下以不同的反应持续时间（5 小时、6 小时、7 小时）煅烧，以产生 N3-/Nb4+ 共掺杂层状结构，随后剥离成超薄纳米片。N3-/Nb4+ 共掺杂纳米片实现了优异的可见光吸收和带隙变窄，这由紫外-可见光谱图谱确定。通过XRD、SEM和AFM证实了块状材料的合成和剥离纳米片的超薄形态。通过 XPS 测量检查元素的化学状态。与 N3-/Nb4+ 共掺杂 CNNO--5hr (510 μmol g-1)、N3- 相比，优化的 N3-/Nb4+ 共掺杂 CNNO--6hr 纳米片在 4 小时后表现出 903 μmol g-1 的优异 O2 演化/Nb4+ 共掺杂的 CNNO--7hr (528 μmol g-1) 和非掺杂的 CNNO-纳米片 (381 μmol g-1)。我们的研究为结合各种化学策略进行先进光催化剂设计的可行性铺平了道路。