Zhang Ying, Lv Haifeng, Zhang Zhen, Wang Lei, Wu Xiaojun, Xu Hangxun
Hefei National Laboratory for Physical Sciences at the Microscale, CAS Key Laboratory of Soft Matter Chemistry, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei, Anhui, 230026, China.
Hefei National Laboratory for Physical Sciences at the Microscale, CAS Center for Excellence in Nanoscience, Department of Materials Science and Engineering, CAS Key Laboratory of Materials for Energy Conversion, University of Science and Technology of China, Hefei, Anhui, 230026, China.
Adv Mater. 2021 Apr;33(15):e2008264. doi: 10.1002/adma.202008264. Epub 2021 Mar 9.
Photo-electrochemical (PEC) water splitting systems using oxide-based photoelectrodes are highly attractive for solar-to-chemical energy conversion. However, despite decades-long efforts, it is still challenging to develop efficient and stable photoelectrodes for practical applications. Here, thin layers of covalent triazine frameworks (CTF-BTh) containing a bithiophene moiety are conformably deposited onto the surfaces of a Cu O photocathode and a Mo-doped BiVO photoanode via electropolymerization to construct new hybrid photoelectrodes, successfully addressing the efficiency and stability issues. The CTF-BTh possesses a suitable band structure to form favorable band edge alignment with each metal oxide, creating a p-n junction and a staggered type-II heterojunction with Cu O and Mo-doped BiVO , respectively. Thus, the as-fabricated hybrid photoelectrodes exhibit substantially increased PEC performances. Meanwhile, the CTF-BTh film also serves as an effective corrosion-resistant overlayer for both photoelectrodes to inhibit photocorrosion and enable long-term operation for 150 h with only ≈10% loss in photocurrent densities. Furthermore, a stand-alone unbiased PEC tandem device comprising CTF-BTh-coated photoelectrodes exhibits 3.70% solar-to-hydrogen conversion efficiency. Even after continuous operation for 120 h, the efficiency can still retain at 3.24%.
使用基于氧化物的光电极的光电化学（PEC）水分解系统对于太阳能到化学能的转换极具吸引力。然而，尽管经过了数十年的努力，开发用于实际应用的高效且稳定的光电极仍然具有挑战性。在此，通过电聚合将含有联噻吩部分的共价三嗪框架（CTF-BTh）薄层均匀地沉积在CuO光阴极和Mo掺杂的BiVO光阳极表面上，以构建新型混合光电极，成功解决了效率和稳定性问题。CTF-BTh具有合适的能带结构，可与每种金属氧化物形成有利的能带边缘对齐，分别与CuO和Mo掺杂的BiVO形成p-n结和交错型II型异质结。因此，所制备的混合光电极表现出显著提高的PEC性能。同时，CTF-BTh膜还作为两种光电极的有效耐腐蚀覆盖层，以抑制光腐蚀，并能够在光电流密度仅损失约10%的情况下进行150小时的长期运行。此外，由CTF-BTh涂层光电极组成的独立无偏压PEC串联装置表现出3.70%的太阳能到氢能转换效率。即使连续运行120小时后，效率仍可保持在3.24%。
