image: Schematic illustration of the mechanism of atomic-level Pt doping to optimize interface chemical bonding for enhanced PEC performance.
Credit: ©Science China Press
The research team successfully constructed an advanced p-n junction composed of atomic-level Pt-doped CeO2 and 2D metalloporphyrins metal-organic framework nanosheets (Pt-CeO2/CuTCPP(Fe)). Atomic-level Pt doping in CeO2 leads to a transition from adsorbed oxygen (Fe-OA) to lattice oxygen (Fe-OL) at the interface, significantly reducing the carrier transport distance and boosting charge transfer efficiency. They achieved a 2.5-fold enhancement in photoelectric performance compared to the conventional CeO2/CuTCPP(Fe) system.
Key findings:
- Atomic-Level Doping: The introduction of atomic-level Pt doping in CeO2 increased the density of oxygen vacancies and induced lattice mutation, facilitating the transition from Fe-OA to Fe-OL bonds.
- Enhanced Charge Transfer: The optimized interfacial chemical bonds reduced the carrier transport distance from 4.41 Å to 1.83 Å, significantly lowering the energy barrier for charge transfer.
- Photoelectric Performance: The Pt-CeO2/CuTCPP(Fe) p-n junction exhibited a 2.5-fold improvement in photoelectric response, making it highly suitable for PEC sensing applications.
- Biosensing Application: Leveraging the peroxidase-like activity of the p-n junction, the team developed a highly sensitive photoelectrochemical immunoassay for the detection of prostate-specific antigens, with a detection limit of 0.71 pg mL-1.
Implications:
This study provides a new strategy for the rational design of advanced heterojunction interfaces with optimized charge transfer pathways. The findings not only deepen our understanding of the relationship between interfacial chemical bonds and photoelectric performance, but also open up new possibilities for the development of high-performance PEC sensors for clinical diagnostics and biomedical research.
Funding:
This work was supported by the National Natural Science Foundation of China, the Natural Science Foundation of Hubei Province, and the Fundamental Research Funds for the Central Universities.