- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
A magnetically recoverable CaTiO<sub>3</sub>/reduced graphene oxide/NiFe<sub>2</sub>O<sub>4</sub> nanocomposite for the dye degradation under simulated sunlight irradiation
摘要： In this work, ternary CaTiO3/reduced graphene oxide (rGO)/NiFe2O4 nanocomposite was successfully prepared using polyacrylamide gel route followed by hydrothermal method. It is observed that NiFe2O4 and CaTiO3 nanoparticles are assembled on the surface of rGO. Furthermore, the formation of chemical bonding between the nanoparticles and rGO is confirmed. The photocatalytic activities of the samples were evaluated through the degradation of methylene blue and rhodamine B under the simulated sunlight irradiation. The results indicate that the ternary nanocomposite exhibits remarkable enhanced photocatalytic activity compared with bare CaTiO3 and NiFe2O4. In this nanocomposite, the photogenerated electrons of CaTiO3 and NiFe2O4 can be captured by rGO, leading to an increased separation and availability of electrons and holes for the photocatalytic reaction. Moreover, this nanocomposite exhibits obvious ferromagnetism and can be readily recovered by external magnetic field. The recycling photocatalytic experiment demonstrates that the nanocomposite possesses good photocatalytic reusability.
关键词： Nanocomposite,CaTiO3,Graphene,NiFe2O4,Photocatalysis
更新于2025-11-19 16:46:39
-
Insulator-Metal Transition in CaTiO<sub>3</sub> Quantum Dots induced by Ultrafast Laser Pulses
摘要： Based on time dependent density functional theory (TDDFT), we have studied the interaction between ultra-fast laser pulses and two kinds of calcium titanate quantum dots (PCTO-QDs and MCTO-QDs). Under the action of localized field effect, ultrafast lasers can induce quantum dots to make the transition from insulator to metal. PCTO-QDs are ultimately metallic, while MCTO-QDs are still insulator after experiencing metal state. This is bacause the stability of the unsaturated atoms in the outermost layer of PCTO-QDs is weak and the geometric configuration of MCTO-QDs as a potential well will also reduce the damage of laser. Moreover, laser waveforms approaching the intrinsic frequency of quantum dots tend to cause the highest electron levels to cross the Fermi surface. In this paper, it is reported that the insulating quantum dots can be transformed into metal by adjusting the intensity and frequency of laser. It emphasizes the importance of local morphology by comparing the difference about two kinds of CTO-QDs. More importantly, it is a step to identify the potential properties of perovskite materials.
关键词： CaTiO3 QDs,metallic transformation,ultra-fast laser
更新于2025-09-23 15:19:57
-
Improvement of photovoltaic performance of perovskite solar cells by interface modification with CaTiO3
摘要： The ETL/perovskite interface is crucial for the photovoltaic performance of perovskite solar cells (PSCs) because of its key role in electrons transport and charge recombination. Herein, an ultrathin CaTiO3 layer has facilely been fabricated and incorporated between the mp-TiO2 and perovskite layers. Due to the trap passivation effect and the optimized energy level alignment induced by modification, the electron transport is facilitated while the charge recombination is suppressed effectively. Therefore, the champion device gains a maximum PCE of 19.12% with the enhanced photovoltaic performance. In addition, the stability of PSCs has also been ameliorated by modification, and about 85% of the initial efficiency can be maintained even after exposure in ambient for 1000h.
关键词： CaTiO3,Perovskite solar cell,ETL,Interface modification
更新于2025-09-12 10:27:22
-
<i>In situ</i> surface modification of TiO <sub/>2</sub> by CaTiO <sub/>3</sub> to improve the UV stability and power conversion efficiency of perovskite solar cells
摘要： The usage of TiO2 in perovskite solar cells is always faced with the risk of device decomposition due to its high photocatalysis activity. To deal with this problem, here in this work, a strategy of in situ surface passivation was proposed and performed on TiO2. After spin-coating Ca(OH)2 solution on a TiO2 mesoporous scaffold and annealing, the surface layer of the scaffold was converted into CaTiO3, as confirmed by X-ray photoemission spectroscopy and X-ray diffraction studies. The modified TiO2 scaffold was then used as an electron-transport-material in perovskite solar cells. It was observed that after moderate modification, the short-circuit current density increased from 22.32 (60.25) to 23.19 (60.28) mA/cm2, the open-circuit voltage rose from 1.042 (60.009) to 1.080 (60.011) V, and the fill factor increased from 63.89 (61.95)% to 71.37 (60.43)%, leading to an improvement from 14.92 (60.36)% to 17.88 (60.37)% of the power conversion efficiency. Transient photocurrent/photovoltage decay curves and impedance spectroscopy tests showed that moderate modification accelerated charge extraction while it retarded charge recombination. Besides, the in situ CaTiO3 layer prolonged the device stability. After being stored in the dark for 46 days (relative humidity of 30%), 92.6% of the initial efficiency was reserved, compared to that of 68.4% for the control devices. Designated UV irradiation showed that the surface passivation retarded the photocatalysis activity of TiO2, which contributed to the prolonged device stability.
关键词： perovskite solar cells,TiO2,UV stability,power conversion efficiency,CaTiO3
更新于2025-09-11 14:15:04
-
Fabrication of photoactive CaTiO3–TiO2 composite thin film electrodes via facile single step aerosol assisted chemical vapor deposition route
摘要： CaTiO3–TiO2 composite oxide films have been employed, for the first time, as photoelectrodes in photoelectrochemical (PEC) splitting of water. The transparent methanol solutions of Ti(Pro)4 and newly synthesized calcium complex [Ca2(TFA)3(OAc)(PrOH)(H2O)(THF)3] (1) (where TFA stands for trifluoroacetato; OAc stands for acetate; and PrOH stands for isopropanol) were utilized for aerosol assisted chemical vapor deposition (AACVD) of the target films. The composite electrodes were deposited on fluorine doped tin oxide (FTO) coated conducting glass substrates at varying deposition temperatures of 500–600 °C. The resulting films were extensively characterized by powder X-ray diffraction, X-ray photoelectron spectroscopy, energy dispersive X-ray analysis and scanning electron microscopy. PEC responses of all the composite electrodes were studied under simulated solar irradiation of AM 1.5 G (100 mW cm?2). The CaTiO3–TiO2 photoanode formed at 600 °C showed higher photocurrent density of 610 μA cm?2 at 0.7 V versus Ag/AgCl/3 M KCl reference electrode as compared to the other two electrodes fabricated similarly with only difference of fabrication temperature (i.e., 500 and 550 °C).
关键词： photoelectrodes,photoelectrochemical water splitting,aerosol assisted chemical vapor deposition,CaTiO3–TiO2 composite
更新于2025-09-10 09:29:36
-
Structure and property of lead-free (K,Na)NbO3–(Bi1/2Na1/2)ZrO3–CaTiO3 piezoelectric ceramics
摘要： Simultaneous improvement of piezoelectricity and temperature stability is vital for developing high-performance KNN-based lead-free materials. Here, effects of CaTiO3 on phase structure, piezoelectricity and temperature stability of (1 – x)[0.95(K0.5Na0.5)NbO3–0.05(Bi0.5Na0.5)ZrO3]–xCaTiO3–0.2%MnO2 ceramics were studied. It was found that the orthorhombic-tetragonal phase transition temperature can be gradually decreased by increasing CaTiO3 content. Particularly, the improved strain temperature stability (strain varied < 15% when measurement temperature reaches 110 °C) and enhanced electrical properties (d33 ~ 296 pC/N and strain ~ 0.14%) can be observed in the ceramics with x = 0.02. Therefore, shifting the TO?T below room temperature is an effective way to promote temperature stability and electrical properties of KNN-based piezoelectric materials.
关键词： Lead-free piezoelectric ceramics,Temperature stability,CaTiO3,Piezoelectricity,KNN-based
更新于2025-09-10 09:29:36