School of Physics, Northwest University, Xi'an, Shaanxi 710069, P. R. China.
Nanoscale. 2018 Jul 5;10(25):11881-11893. doi: 10.1039/c8nr03040e.
Excellent PEC efficiency, good reusability and the super stability of trap-like SnS2/TiO2 nanotube arrays (NTs)-based photoanodes are reported. Specifically, the SnS2/TiO2-180 °C (ST-180) photoanode exhibited the highest photocurrent density (1.05 mA cm-2) and an optimal η (0.73%) at 0.5 V (vs. SCE) under simulated light irradiation (AM 1.5G), which are 4.6 and 3.8 times higher than those of pure TiO2 NTs (0.23 mA cm-2 and 0.19%). The IPCE values of ST-180 can reach 21.5% (365 nm) and 13.8% (420 nm), which are much higher than those of pure TiO2 NTs (10.6% at 365 nm and 0.8% at 420 nm). The APCE values of the pure TiO2 NTs photoelectrode are 12.8% (365 nm) and 1.1% (420 nm), while the ST-180 values are 22.3% and 14.2%, respectively. Furthermore, the generation rates of H2 and O2 for the ST-180 photoanode are 47.2 and 23.1 μmol cm-2 h-1 at 0.5 V under AM 1.5G, corresponding to faradaic efficiencies of around 80.1% and 78.3%, respectively. In short, the high-efficiency PEC water splitting performance of this SnS2/TiO2 photoanode results from the enhanced light harvesting ability of the trap-like SnS2 structure, accelerated carrier transportation properties of TiO2 NTs, and effective carrier separation of the type-II heterojunction structure. This work may offer a combinatorial strategy for the preparation of heterojunction structures with high PEC performance and can be a model structure for similar photoanode materials.
报道了具有优异的 PEC 效率、良好的可重复使用性和超稳定性的陷阶型 SnS2/TiO2 纳米管阵列（NTs）基光阳极。具体来说，SnS2/TiO2-180°C（ST-180）光阳极在模拟光照（AM 1.5G）下表现出最高的光电流密度（1.05 mA cm-2）和最佳的 η（0.73%），在 0.5 V（相对于 SCE）时，这分别是纯 TiO2 NTs（0.23 mA cm-2 和 0.19%）的 4.6 倍和 3.8 倍。ST-180 的 IPCE 值在 365nm 时可达 21.5%，在 420nm 时可达 13.8%，远高于纯 TiO2 NTs（365nm 时为 10.6%，420nm 时为 0.8%）。纯 TiO2 NTs 光电电极的 APCE 值分别为 365nm 时的 12.8%和 420nm 时的 1.1%，而 ST-180 的值分别为 22.3%和 14.2%。此外，在 AM 1.5G 下，ST-180 光阳极在 0.5V 时的 H2 和 O2 的生成速率分别为 47.2 和 23.1 μmol cm-2 h-1，相应的法拉第效率约为 80.1%和 78.3%。总之，这种 SnS2/TiO2 光阳极具有高效的 PEC 水分解性能，这是由于陷阶型 SnS2 结构增强了光捕获能力、TiO2 NTs 加速了载流子输运性能以及 II 型异质结结构的有效载流子分离。这项工作为制备具有高 PEC 性能的异质结结构提供了一种组合策略，并可以作为类似光阳极材料的模型结构。
