研究目的
Investigating the effect of Nd dopant in charge transfer mechanism by comparing both the BFO and BNFO samples for PEC application as well as to understand the heterojunction band offsets at multiferroic/metal and multiferroic/electrolyte interfaces.
研究成果
In conclusion, we have demonstrated that the heterojunction band offsets at multiferroic/metal and multiferroic/electrolyte interfaces play the key role in determining the charge transport pathway to control photochemical activity, despite a downward self-polarization state in the multiferroic films. More importantly, apart from low leakage current and increased optical absorption, we have discovered that the Nd dopant provides effective charge separation and transfer mechanism in PEC application. By doping Nd into BFO, the photocurrent of BNFO (100)pc increases more than two fold of BFO (100)pc. We believe the enhanced PEC performance was attributed to the core level shift of Sr3d and Bi4f allowing Fermi level to move closer to the conductive band and hence increases the charge transfer efficiency.
研究不足
The technical and application constraints of the experiments, as well as potential areas for optimization, are not explicitly mentioned in the paper.
1：Experimental Design and Method Selection:
The 5 % BNFO film was epitaxially grown on SRO buffered STO (100) single crystal substrate by PLD with a 248 nm excimer KrF laser. The laser energy was set at 180 MJ with repetition rate of 10 Hz. The conductive SRO layer was served as the bottom electrode for electrical characterization and to achieve downward self-polarization direction.
2：Sample Selection and Data Sources:
The SRO layer was deposited on the substrate with temperature of 700 °C in a dynamic oxygen pressure of 100 mTorr for 30 minutes. After that, BNFO film was grown at 650 °C in a dynamic oxygen pressure of 200 mTorr for 60 minutes. After the thin film growth, sample was cooled to room temperature under a static oxygen pressure of 200 Torr to minimize the creation of oxygen vacancies.
3：List of Experimental Equipment and Materials:
Bruker D8 Discover X-Ray Diffraction (XRD), FEI Tecnai F20 transmission electron microscope, SPECs Phoibos 150 Hemispherical Energy Analyzer system, Jasco V-670 absorption spectrophotometer, Bruker Multimode 8 atomic force microscope (AFM) with Nanoscope V controller.
4：Experimental Procedures and Operational Workflow:
The phase formations and the epitaxial relationship between BNFO (or BFO), SRO and STO of the photocatalyst were confirmed by using XRD. TEM characterizations have been carried out by using an FEI Tecnai F20 transmission electron microscope. The XPS measurements were carried out at room temperature on a SPECs Phoibos 150 Hemispherical Energy Analyzer system. The absorption spectrum of the samples was analyzed at room temperature using a Jasco V-670 absorption spectrophotometer. The current-voltage characteristic, surface potential and piezoelectric response of the samples were analyzed using C-AFM, KPFM, piezoresponse force microscope (PFM) from Bruker Multimode 8 atomic force microscope (AFM) with Nanoscope V controller.
5：Data Analysis Methods:
The electronic band structures and transport properties of our samples are revealed by several techniques such as Nyquist, Kelvin Probe Force Microscopy (KPFM), X-ray photoelectron spectroscopy (XPS) and Conductive Atomic Force Microscopy (C-AFM).
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
