CNR-Istituto di Scienze e Tecnologie Molecolari , Via C. Golgi 19, 20133 Milano, Italy.
ACS Appl Mater Interfaces. 2014 Aug 13;6(15):11997-2004. doi: 10.1021/am5030287. Epub 2014 Jul 16.
A new nanostructured α-Fe2O3 photoelectrode synthesized through plasma-enhanced chemical vapor deposition (PE-CVD) is presented. The α-Fe2O3 films consist of nanoplatelets with (001) crystallographic planes strongly oriented perpendicular to the conductive glass surface. This hematite morphology was never obtained before and is strictly linked to the method being used for its production. Structural, electronic, and photocurrent measurements are employed to disclose the nanoscale features of the photoanodes and their relationships with the generated photocurrent. α-Fe2O3 films have a hierarchical morphology consisting of nanobranches (width ∼10 nm, length ∼50 nm) that self-organize in plume-like nanoplatelets (350-700 nm in length). The amount of precursor used in the PE-CVD process mainly affects the nanoplatelets dimension, the platelets density, the roughness, and the photoelectrochemical (PEC) activity. The highest photocurrent (j = 1.39 mA/cm(2) at 1.55 VRHE) is shown by the photoanodes with the best balance between the platelets density and roughness. The so obtained hematite hierarchical morphology assures good photocurrent performance and appears to be an ideal platform for the construction of customized multilayer architecture for PEC water splitting.
通过等离子体增强化学气相沉积 (PE-CVD) 合成了一种新型的纳米结构 α-Fe2O3 光电 极。α-Fe2O3 薄膜由纳米板组成，具有强烈垂直于导电玻璃表面的 (001) 晶面取向。这种赤铁矿形态以前从未获得过，并且与用于制备它的方法严格相关。结构、电子和光电流测量用于揭示光阳极的纳米级特征及其与产生的光电流的关系。α-Fe2O3 薄膜具有分层形态，由纳米支链（宽度约为 10nm，长度约为 50nm）组成，这些纳米支链自组织成羽毛状纳米板（长度为 350-700nm）。PE-CVD 工艺中使用的前驱体的量主要影响纳米板的尺寸、板密度、粗糙度和光电化学（PEC）活性。具有最佳板密度和粗糙度平衡的光阳极表现出最高的光电流（j = 1.39 mA/cm2 在 1.55 VRHE 时）。如此获得的赤铁矿分层形态确保了良好的光电流性能，并且似乎是构建用于 PEC 水分解的定制多层结构的理想平台。
