Chen Qianyuan, Wang Zhongchi, Chen Keqiang, Fu Qiang, Liu Yueli, Zhang Yupeng, Li Delong, Pan Chunxu
School of Physics and Technology, MOE Key Laboratory of Artificial Micro- and Nano-structures, Wuhan University Wuhan 430072 China
Institute of Microscale Optoelectronics, College of Electronic Science and Technology, Shenzhen Key Laboratory of Flexible Memory Materials and Devices, Shenzhen University Shenzhen 518060 China
RSC Adv. 2019 Oct 21;9(58):33747-33754. doi: 10.1039/c9ra07237c. eCollection 2019 Oct 18.
The growing demands for reproducible and clean sources of power has prompted the exploitation of novel materials for solar-energy conversion; in any case, the improvement of their conversion efficiency remains a big challenge. We report a mixed-dimensional heterostructure to synchronously enhance charge separation and light-absorption of the photoanodes the introduction of two-dimensional reduced graphene oxide and zero-dimensional CuSbS quantum dots on one-dimensional TiO arrays. The experimental results show that the graphene sheets with a low Fermi level and a superior electron mobility accept photo-excited electrons from TiO and enable fast electron transportation; while the CuSbS quantum dots promote the visible light-absorption of the photoanode. The synergistic effects in this mixed-dimensional (1D-2D-0D) heterostructure photoanode induce a markedly raised photoconversion efficiency of 1.2% at 0.3 V and a photocurrent density of 5.5 mA cm at 0.4 V. Furthermore, the photocurrent density of the mixed-dimensional heterostructure exceeds previously reported TiO-based photoanodes in neutral media. The improved photoelectrochemical properties are attributed to the synergistic-effect-induced highly organized, mixed-dimensional architectures. It is expected that the mixed-dimensional heterostructure photoanode will be a potential candidate for applications in environmental remediation and energy fields.
对可再生和清洁能源日益增长的需求促使人们开发用于太阳能转换的新型材料；无论如何，提高其转换效率仍然是一个巨大的挑战。我们报道了一种混合维度异质结构，通过在一维TiO阵列上引入二维还原氧化石墨烯和零维CuSbS量子点，同步增强光阳极的电荷分离和光吸收。实验结果表明，具有低费米能级和优异电子迁移率的石墨烯片从TiO接受光激发电子并实现快速电子传输；而CuSbS量子点促进了光阳极的可见光吸收。这种混合维度（1D-2D-0D）异质结构光阳极中的协同效应在0.3 V时诱导出显著提高的1.2%的光转换效率，在0.4 V时诱导出5.5 mA cm的光电流密度。此外，混合维度异质结构的光电流密度在中性介质中超过了先前报道的基于TiO的光阳极。光电化学性能的改善归因于协同效应诱导的高度有序的混合维度结构。预计混合维度异质结构光阳极将成为环境修复和能源领域应用的潜在候选者。
