Qi Huan, Wolfe Jonathan, Wang Danping, Fan Hong Jin, Fichou Denis, Chen Zhong
School of Materials Science Engineering, Nanyang Technological University, Singapore 639798, Singapore.
Nanoscale. 2014 Nov 21;6(22):13457-62. doi: 10.1039/c4nr03982c.
Unique nanorods/nanoparticles/nanoflakes (NRs/NPs/NFs) WO3 triple-layers are grown on a metallic W foil by a simple one-step anodization method. The triple-layered structure is formed through a self-organization process, the film thickness (up to 3 μm) being controlled by the anodization time. A first layer made of an array of WO3 densely-packed vertically-aligned NRs (1.2-1.4 μm in height) grow atop the tungsten foil, followed by a second layer of small NPs (50-80 nm) and finally a third layer made of rectangular NFs (200-300 nm). When irradiated by white light in a photoelectrochemical cell these WO3 triple-layers generate a photocurrent as high as 0.9 mA cm(-2) at 1.2 V/RHE. Moreover, we show that the stability of the triple-layered WO3 photoanodes can be considerably enhanced by adding an ultrathin (10 nm) TiO2 protective overlayer.
通过简单的一步阳极氧化法，在金属钨箔上生长出独特的纳米棒/纳米颗粒/纳米薄片（NRs/NPs/NFs）三氧化钨（WO₃）三层结构。这种三层结构是通过自组装过程形成的，膜厚度（可达3μm）由阳极氧化时间控制。由紧密排列的垂直对齐的WO₃纳米棒阵列（高度为1.2 - 1.4μm）构成的第一层生长在钨箔顶部，接着是由小纳米颗粒（50 - 80nm）组成的第二层，最后是由矩形纳米薄片（200 - 300nm）构成的第三层。当在光电化学电池中用白光照射时，这些WO₃三层结构在1.2V/RHE下产生高达0.9mA cm⁻²的光电流。此外，我们表明，通过添加超薄（10nm）二氧化钛（TiO₂）保护覆盖层，可以显著提高三层WO₃光阳极的稳定性。
