Liu Jingyuan, Hisatomi Takashi, Murthy Dharmapura H K, Zhong Miao, Nakabayashi Mamiko, Higashi Tomohiro, Suzuki Yohichi, Matsuzaki Hiroyuki, Seki Kazuhiko, Furube Akihiro, Shibata Naoya, Katayama Masao, Minegishi Tsutomu, Domen Kazunari
Department of Chemical System Engineering, School of Engineering, The University of Tokyo , 7-3-1 Hongo, Bunkyo-ku, 113-8656 Tokyo, Japan.
Japan Technological Research Association of Artificial Photosynthetic Chemical Process (ARPChem) , 2-11-9 Iwamotocho, Chiyoda-ku, 101-0032 Tokyo, Japan.
J Phys Chem Lett. 2017 Jan 19;8(2):375-379. doi: 10.1021/acs.jpclett.6b02735. Epub 2017 Jan 4.
Particulate LaTiCuSO (LTC) photocathodes prepared by particle transfer show a positive onset potential of 0.9 V vs RHE for the photocathodic current in photoelectrochemical (PEC) H evolution. However, the low photocathodic current imposes a ceiling on the solar-to-hydrogen energy conversion efficiency of PEC cells based on LTC photocathodes. To improve the photocurrent, in this work, the surface of Mg-doped LTC photocathodes was modified with TiO, NbO, and TaO by radio frequency reactive magnetron sputtering. The photocurrent of the modified Mg-doped LTC photocathodes was doubled because these oxides formed type-II heterojunctions and extended the lifetimes of photogenerated charge carriers. The enhanced photocathodic current was attributed to hydrogen evolution at a positive potential of +0.7 V vs RHE. This work opens up possibilities for improving PEC hydrogen evolution on particulate photocathodes based on surface oxide modifications and also highlights the importance of the band gap alignment.
通过颗粒转移制备的颗粒状LaTiCuSO（LTC）光阴极在光电化学（PEC）析氢过程中，对于光电流而言，相对于可逆氢电极（RHE）显示出0.9 V的正起始电位。然而，低光电流限制了基于LTC光阴极的PEC电池的太阳能到氢能的能量转换效率。为了提高光电流，在这项工作中，通过射频反应磁控溅射用TiO、NbO和TaO对掺镁LTC光阴极的表面进行了改性。改性后的掺镁LTC光阴极的光电流增加了一倍，因为这些氧化物形成了II型异质结并延长了光生电荷载流子的寿命。增强的光电流归因于相对于RHE在+0.7 V的正电位下的析氢。这项工作为基于表面氧化物改性改善颗粒光阴极上的PEC析氢开辟了可能性，同时也突出了带隙对准的重要性。
