Yue Shuai, Chen Lu, Zhang Manke, Liu Zhe, Chen Tao, Xie Mingzheng, Cao Zhen, Han Weihua
Key Laboratory for Environmental Pollution Prediction and Control of Gansu Province, College of Earth and Environmental Sciences, Lanzhou University, Lanzhou, 730000, People's Republic of China.
School of Physical Science and Technology, Lanzhou University, Lanzhou, 730000, People's Republic of China.
Nanomicro Lett. 2021 Dec 6;14(1):15. doi: 10.1007/s40820-021-00749-6.
The recombination loss of photo-carriers in photocatalytic systems fatally determines the energy conversion efficiency of photocatalysts. In this work, an electrostatic field was used to inhibit the recombination of photo-carriers in photocatalysts by separating photo-holes and photo-electrons in space. As a model structure, (010) facet-exposed BiVO nanowires were grown on PDMS-insulated piezo-substrate of piezoelectric transducer (PZT). The PZT substrate will generate an electrostatic field under a certain stress, and the photocatalytic behavior of BiVO nanowires is influenced by the electrostatic field. Our results showed that the photocatalytic performance of the BiVO nanowires in CO reduction in the negative electrostatic field is enhanced to 5.5-fold of that without electrostatic field. Moreover, the concentration of methane in the products was raised from 29% to 64%. The enhanced CO reduction efficiency is mainly attributed to the inhibited recombination loss of photo-carriers in the BiVO nanowires. The increased energy of photo-carriers and the enhanced surface absorption to polar molecules, which are CO in this case, were also play important roles in improving the photocatalytic activity of the photocatalyst and product selectivity. This work proposed an effective strategy to improve photo-carriers separation/transfer dynamics in the photocatalytic systems, which will also be a favorable reference for photovoltaic and photodetecting devices.
光催化体系中光生载流子的复合损失严重决定了光催化剂的能量转换效率。在这项工作中，通过在空间上分离光生空穴和光生电子，利用静电场抑制光催化剂中光生载流子的复合。作为模型结构，在压电换能器（PZT）的PDMS绝缘压电基板上生长了（010）面暴露的BiVO纳米线。PZT基板在一定应力下会产生静电场，BiVO纳米线的光催化行为受该静电场影响。我们的结果表明，在负静电场中BiVO纳米线在CO还原中的光催化性能提高到无静电场时的5.5倍。此外，产物中甲烷的浓度从29%提高到64%。CO还原效率的提高主要归因于BiVO纳米线中光生载流子复合损失的抑制。光生载流子能量的增加以及对极性分子（在这种情况下为CO）表面吸收的增强，在提高光催化剂的光催化活性和产物选择性方面也起着重要作用。这项工作提出了一种有效策略来改善光催化体系中光生载流子的分离/转移动力学，这也将为光伏和光探测器件提供有益参考。
