Catalysis and Nanomaterials Lab 27, Department of Chemistry, Quaid-i-Azam University , Islamabad 45320, Pakistan.
Department of Electronic and Computer Engineering, Hong Kong University of Science and Technology , Clear Water Bay, Kowloon, Hong Kong SAR, China.
ACS Appl Mater Interfaces. 2016 Dec 28;8(51):35315-35322. doi: 10.1021/acsami.6b12460. Epub 2016 Dec 16.
Recently, photoelectrochemical conversion (PEC) of water into fuel is attracting great attention of researchers due to its outstanding benefits. Herein, a systematic study on PEC of water using CuFeO/ α-FeO composite thin films is presented. CuFeO/ α-FeO composite thin films were deposited on two different substrates; (1) planner FTO glass and (2) 3-dimensional nanospike (NSP). The films on both substrates were characterized and tested as anode material for photoelectrochemical water splitting reaction. During PEC studies, it was observed that the ratio between two components of composite is crucial and highest PEC activity results were achieved by 1:1 component ratio (CF-1) of CuFeO and α-FeO. The CF-1 ratio sample deposited on planar FTO substrate provided a photocurrent density of 1.22 mA/cm at 1.23 V which is 1.9 times higher than bare α-FeO sample. A significant PEC activity outperformance was observed when CF-1 ratio composite thin films were deposited on 3D NSP. The highest photocurrent density of 2.26 mA/cm at 1.23 V was achieved for 3D NSP sample which is around 3.6 times higher than photocurrent density generated by α-FeO thin film only. The higher photocurrent densities of 3D nanostructured devices compared to planar one are attributed to the enhanced light trapping and increased surface area for photoelectrochemical water oxidation on the surface. The difference between valence and conduction bands of CuFeO and α-FeO allows better separation of photogenerated electrons and holes at the CuFeO/ α-FeO interface which makes it more active for photoelectrochemical water splitting.
最近，由于光电化学（PEC）水转化为燃料具有突出的优势，因此引起了研究人员的极大关注。在此，我们对使用 CuFeO/α-FeO 复合薄膜的水 PEC 进行了系统的研究。CuFeO/α-FeO 复合薄膜沉积在两种不同的基底上；（1）平面 FTO 玻璃和（2）三维纳米刺（NSP）。对两种基底上的薄膜进行了特性和测试，作为光电化学水分解反应的阳极材料。在 PEC 研究中，观察到复合的两种成分的比例是至关重要的，并且通过 CuFeO 和α-FeO 的 1:1 成分比（CF-1）获得了最高的 PEC 活性。在平面 FTO 基底上沉积的 CF-1 比例样品在 1.23 V 时提供了 1.22 mA/cm 的光电流密度，这比纯α-FeO 样品高 1.9 倍。当 CF-1 比例复合薄膜沉积在 3D NSP 上时，观察到显著的 PEC 活性增强。在 3D NSP 样品中，在 1.23 V 时获得了 2.26 mA/cm 的最高光电流密度，这比仅由α-FeO 薄膜产生的光电流密度高约 3.6 倍。与平面结构相比，3D 纳米结构器件的更高光电流密度归因于在 3D NSP 表面增强的光捕获和增加的光电化学水氧化表面积。CuFeO 和α-FeO 的价带和导带之间的差异允许在 CuFeO/α-FeO 界面更好地分离光生电子和空穴，从而使其更适合用于光电化学水分解。
