Carbon Dot Loading and TiO2 Nanorod Length Dependence of Photoelectrochemical Properties in Carbon Dot/TiO2 Nanorod Array Nanocomposites
Carbon Dot Loading and TiO2 Nanorod Length Dependence of Photoelectrochemical Properties in Carbon Dot/TiO2 Nanorod Array Nanocomposites
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DOI：
10.1021/am4059183
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发表时间：
2014-04-09
影响因子：
9.5
通讯作者：
Zhang, Ruiqin
中科院分区：
文献类型：
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作者：
Bian, Juncao;Huang, Chao;Zhang, Ruiqin
TiO2 纳米棒阵列 (TNRA) 的光电化学 (PEC) 特性已得到广泛研究，因为它们具有光稳定性和成本效益。然而，由于禁带宽度较宽，TiO2 只能利用太阳光的紫外部分。为了增强 TNRA 在可见光范围内的光响应，本工作采用碳点（C 点）作为绿色敏化剂，研究 C 点负载量和 TiO2 纳米棒长度对 TNRA/C 点纳米复合材料 PEC 性能的影响。随着C点负载量的增加，纳米复合材料的光电流密度增强，并在C点浓度为0.4 mg/mL时达到最大值。 C点浓度的进一步增加降低了光电流，这可能是由C点的表面聚集引起的。随着 TiO2 纳米棒长度的增加，电荷传输和电荷收集之间存在折衷。 TNRA/C点纳米复合材料在可见光范围内的入射光子电流转换效率(IPCE)高达1.2-3.4%。这项工作可以为基于C点的PEC电池高效光电阳极的制造提供指导。
Photoelectrochemcial (PEC) properties of TiO2 nanorod arrays (TNRA) have been extensively investigated as they are photostable and cost-effective. However, due to the wide band gap, only the UV part of solar light can be employed by TiO2. To enhance the photoresponse of TNRA in the visible range, carbon dots (C dots) were applied as green sensitizer in this work by investigating the effects of C dot loading and length of TiO2 nanorod on the PEC properties of TNRA/C dot nanocomposites. As the C dot loading increases, the photocurrent density of the nanocomposites was enhanced and reached a maximum when the concentration of the C dots was 0.4 mg/mL. A further increase in the C dot concentration decreased the photocurrent, which might be caused by the surface aggregation of C dots. A compromise existed between charge transport and charge collection as the length of TiO2 nanorod increased. The incident photon to current conversion efficiency (IPCE) of the TNRA/C dot nanocomposites in the visible range was up to 1.2-3.4%. This work can serve as guidance for fabrication of highly efficient photoanode for PEC cells based on C dots.