image: With the interface, defect and surface engineering strategies, the half-cell STH efficiency record of Ta3N5 photoanode has been progressively improved.
Credit: ©Science China Press
This feature article is led by Prof. Yanbo Li and Dr. Beibei Zhang (Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China), who have been dedicated to enhancing the efficiencies of the three fundamental processes in photoelectrocatalysis: light absorption, photogenerated carrier separation, and surface catalytic conversion.
Through these efforts, Li’s group has achieved progressive improvements in the half-cell solar-to-hydrogen (STH) conversion efficiency record of the Ta3N5 photoanode. Specifically, they have highlighted the following key points:
- Defect Formation Mechanism: They elucidated the formation mechanism of performance-limiting deep-level defects in Ta3N5, providing guidance for performance improvement.
- Gradient Mg Doping for Charge Separation: A gradient Mg doping profile was designed to match the defect distribution and construct a gradient band structure, significantly enhancing bulk charge separation efficiency.
- La Doping for Light Absorption: La doping was employed to enhance near-band-edge light absorption by alleviating anisotropic optical absorption. Additionally, a heterogeneous La/Mg doping strategy was proposed to decouple light absorption and carrier transport.
- Interface Engineering for Charge Extraction: In:GaN/Ta3N5/Mg:GaN planar heterojunction and NbNx@Mg:Ta3N5 core-shell NRs were constructed through interface engineering, improving interfacial charge extraction efficiency.
- Self-Healing OER Catalyst: A new self-healing mechanism was proposed, and a self-healing NiCoFe-Bi catalyst with a unique thickness self-limiting property was developed, making it ideally suited for PEC applications.
These advancements represent significant contributions to the field of photoelectrocatalysis and hold promise for further improving the efficiency and stability of PEC water splitting systems. The improvements in the efficiency of the Ta3N5 photoanode to a record-high level of above 4% are noteworthy. These research advances have important guiding significance for the further development of the PEC field, and are expected to further improve the efficiency and stability of PEC water splitting systems.
See the article:
Engineering Tantalum Nitride for Efficient Photoelectrochemical Water Splitting
https://doi.org/10.1007/s11426-024-2058-9
Journal
Science China Chemistry