Free Electron Spin Research Articles

Using Light to Polarize and Detect Electron Spins in Silicon.

Despite decades of research, demonstration of all-optical detection and control of free electron spins in silicon remains elusive. Here, we directly probe the electron spin properties in bulk silicon by measuring the polarization of luminescence following circularly polarized light excitation. The all-optical experiments performed for both direct and indirect gap excitation allow not only an experimental determination of the optical selection rules in silicon for the different phonon-assisted transitions but they also lead to the measurement of the spin relaxation of electrons in conditions that are not accessible using transport techniques. We also measure the spin properties of free excitons in bulk silicon, a very little explored field.

Fabrication of α-Fe2O3/TiO2 heterojunction for photocatalytic degradation of doxycycline hydrochloride

Fabrication of α-Fe2O3/TiO2 heterojunction for photocatalytic degradation of doxycycline hydrochloride

Graphene quantum dot modified Bi2MoO6 nanoflower for efficient degradation of BPA under visible light

Graphene quantum dot modified Bi2MoO6 nanoflower for efficient degradation of BPA under visible light

Design of ternary GO@AgNPs@g-C3N4 membranes for efficient dye removals in integrated photocatalysis-filtration reactors

Design of ternary GO@AgNPs@g-C3N4 membranes for efficient dye removals in integrated photocatalysis-filtration reactors

Visible-light-driven Z-scheme ZnTe/WO3 heterojunction for simultaneous elimination of tetracycline and Cu(II)

Visible-light-driven Z-scheme ZnTe/WO3 heterojunction for simultaneous elimination of tetracycline and Cu(II)

A flower-like g-C3N4/CDs/Bi2WO6 hierarchical structure for enhanced photocatalytic degradation of tetracycline

A flower-like g-C3N4/CDs/Bi2WO6 hierarchical structure for enhanced photocatalytic degradation of tetracycline

Synthesis of MoS2@MoO3/(Cu+/g-C3N4) ternary composites with double S-scheme heterojunction for peroxymonosulfate activation exposing to visible light

Synthesis of MoS2@MoO3/(Cu+/g-C3N4) ternary composites with double S-scheme heterojunction for peroxymonosulfate activation exposing to visible light

Synergistic enhancement of singlet oxygen generation in Au and oxygen vacancy co-modified Bi2MoO6 ultrathin nanosheets for efficient ciprofloxacin degradation

Synergistic enhancement of singlet oxygen generation in Au and oxygen vacancy co-modified Bi2MoO6 ultrathin nanosheets for efficient ciprofloxacin degradation

Photo-Fenton Degradation of Tetracycline and Photoelectrochemical Properties of ZnFe2O4@ZnWO4 Heterostructure Composite Coupling.

Problems such as bacterial resistance caused by tetracycline antibiotics pose a serious threat to human production and life and ecosystems. We prepared ZnFe2O4@ZnWO4 heterojunction nanocomposites using hydrothermal and coprecipitation methods. The micromorphology, structure, and photoelectrochemical properties were analyzed. In combination with the presence of H2O2, the photo-Fenton activity of the antibiotic tetracycline at high concentration was tested under visible light irradiation, and its catalytic mechanism was investigated. The results showed that the composition of the composite heterojunction improved the catalytic activity of the catalyst. At a pollutant concentration of 50 mg L-1 and pH 5, 30% ZnWO4/ZnFe2O4 degraded 92.1% of tetracycline in 60 min with a degradation rate of 0.0295 min-1, which was 6.7 times higher than that of pure ZnFe2O4. The results of free radical trapping experiments and electron spin resonance techniques indicated that hydroxyl radical (•OH) and superoxide radical (O2-) played important roles in the photo-Fenton degradation of tetracycline. Notably, the catalyst maintained a high degradation rate (80%) after five cycles. ZnFe2O4 introduced in this article may provide a promising strategy for achieving strong light absorption and is authoritative in meeting future environmental requirements.

Free electrons spin-dependent Kapitza-Dirac effect in two-dimensional triangular optical lattice.

The free electron spin dynamics in Kapitza-Dirac (KD) effect had been studied theoretically in one-dimensional standing wave of EUV to X-ray laser with extremely high intensity, which is far beyond experimental realization. Here, we propose to achieve the free electron spin-dependent KD effect in two-dimensional triangular optical lattice with spatial inversion symmetry breaking, and the theoretical results reveal that laser with wavelength in visible or near-IR and five orders of magnitude decreased intensity could lead to obvious spin-dependent KD effect. This work provides the way to realize the free electron spin-dependent KD effect experimentally.

Efficient photocatalytic degradation of ethylenethiourea with zinc oxide photocatalysts: Parameters optimization, mechanism insight, exploration of degradation pathways and toxicity assessment

Efficient photocatalytic degradation of ethylenethiourea with zinc oxide photocatalysts: Parameters optimization, mechanism insight, exploration of degradation pathways and toxicity assessment

Integrating AgFeO2 and Bi5O7I to establish an S-scheme heterojunction with significantly boosted norfloxacin photocatalytic degradation

Integrating AgFeO2 and Bi5O7I to establish an S-scheme heterojunction with significantly boosted norfloxacin photocatalytic degradation

Efficient Photocatalytic Activation of Peroxymonosulfate by Cobalt-Doped Oxygen-Vacancies-Rich BiVO4 for Rapid Tetracycline Degradation.

In this work, cobalt-doped oxygen-vacancies-rich BiVO4 (Co/BiVO4-Vo) was successfully synthesized for the degradation of tetracycline (TC) by activated peroxymonosulfate (PMS) under visible light. The morphologies, microstructures, and optical properties of the photocatalysts were analyzed in detail. Co/BiVO4-Vo exhibited significantly enhanced degradation, removing 92.3% of TC within 10 min, which was greater than those of pure BiVO4 (62.2%) and oxygen-vacancies-rich BiVO4 (BiVO4-Vo) (72.0%), respectively. The photogenerated charge separation and transport properties were explored through surface photovoltage (SPV), photoluminescence spectrum (PL), and UV-vis diffuse reflectance spectroscopy (UV-vis DRS) measurements. Additionally, an in-depth investigation was conducted on the photocatalytically assisted advanced oxidation processes based on SO4•- (SR-AOPs) for the degradation of organic pollutants. The experimental results showed that the introduction of oxygen vacancies and Co doping achieved an effective separation of photogenerated carriers, which could accelerate the cycling between Co3+ and Co2+ and further activate PMS. The results of free radical capture experiments and electron spin resonance (ESR) experiments showed that reactive oxygen species (ROSs) such as 1O2, •O2-, and SO4•- played a dominant role in the removal of pollutants. This work provides a novel insight into the further development of efficient and rapid PMS photoactivators for environmental remediation of water bodies.

Magnetically separable Z-scheme ZnFe2O4/MoS2 photocatalyst for boosting photo-Fenton degradation activity by a hole-mediated mechanism

Magnetically separable Z-scheme ZnFe2O4/MoS2 photocatalyst for boosting photo-Fenton degradation activity by a hole-mediated mechanism

Synergistic photocatalysis of oxygen-enriched vacancy BiOBr based on rice husk biochar: Efficient seawater purification achieved by carrier directional migration

Synergistic photocatalysis of oxygen-enriched vacancy BiOBr based on rice husk biochar: Efficient seawater purification achieved by carrier directional migration

Highly efficient CdS/SbVO4 composites for visible-light-driven Cr(VI) reduction

Highly efficient CdS/SbVO4 composites for visible-light-driven Cr(VI) reduction

A Novel Bismuth‐Rich Bi3O4Cl/BixOyIz Composite with Intensified Photocatalytic Internal Electrical Field for Photocatalytic Degradation of Antibiotics

The enhancement of photocatalytic semiconductor degradation performance through a bismuth‐rich strategy and heterojunction engineering is considered a very effective approach. Herein, the bismuth‐rich Bi3O4Cl/BixOyIz composites are synthesized through a simple solvothermal reaction. The composites have an internal electric field because of their specific layered structure. Due to the difference between their covalent [BixOy]2+ layer and exchangeable halogen ion layer, the enhanced internal electric field facilitates electron transfer at the high‐quality interface of the semiconductor. The trace presence of Bi3O4Cl/BixOyIz (0.1 g L−1) can achieve an 88% removal of tetracycline (20 mg L−1) from the solution phase under visible light illumination in 120 min. The photocatalytic activity is much higher than that of pure BiOCl and BiOI. Furthermore, the material also exhibits high photocatalytic degradation performance for bisphenol A, doxycycline hydrochloride, etc. The excellent results further confirm the application range of the prepared photocatalysts. The superior photocatalytic activity of Bi3O4Cl/BixOyIz is attributed to the formation of a heterojunction and the generation of an internal electric field, which enhances charge separation and oxidation ability. Photoelectrochemical characterization can confirm the above views. Free radical trapping experiments and electron spin resonance show that heterojunctions can produce abundant •O2− and •OH under visible light irradiation.

A Co-doped Ag3PO4 photocatalyst: Efficient degradation of organic pollutants and enhancement mechanism

A Co-doped Ag3PO4 photocatalyst: Efficient degradation of organic pollutants and enhancement mechanism

Three-dimensional porous La(OH)3/g-C3N4 adsorption-photocatalytic synergistic removal of tetracycline.

La(OH)3/g-C3N4 composites were successfully synthesized via one-step calcination using urea, melamine, and La(NO3)3·nH2O as raw materials, and applied to UV-induced photocatalytic tetracycline (TC) removal. Comprehensive characterization by an X-ray diffraction (XRD), Fourier transform infrared reflection (FT-IR), high-resolution transmission electron microscope (HRTEM), and other techniques analyzed effects of La3+ doping, especially N vacancies and cyano groups as active sites. Compared to pure g-C3N4 and La(OH)3, synthesized La(OH)3/g-C3N4 composites exhibited a three-dimensional porous nanosheet structure with specific surface area of 83.62 m2/g and equilibrium TC adsorption capacity up to 285.59 mg/g; La(OH)3 doping significantly improved composite structure. After dispersing 10 mg La-CN-0.5 photocatalyst in 60 mL 40 mg/L TC solution, TC removal reached 91.08% in 30 min under UV irradiation, exhibiting excellent performance. Additionally, La-CN-0.5 showed significant adsorption-photocatalytic synergism, with the quasi-primary kinetic constant increased by 1.83-fold. The efficiency of high tetracycline (TC) concentration treatment through adsorption photocatalytic degradation by La-CN-0.5 was confirmed by the utilization of free radical trapping and electron spin resonance (ESR) tests. The significant involvement of ∙O2-, ∙OH, and h+ in this process was observed. These findings propose that the prepared La-CN-0.5 material exhibits a unique capability for adsorption photocatalysis, providing a promising approach for the efficient removal of high TC concentrations.

Unraveling the generation mechanism of singlet oxygen in Bi2WxMo1-xO6 solid solution and roles in photocatalytic degradation of gaseous toluene under visible-light irradiation

Unraveling the generation mechanism of singlet oxygen in Bi2WxMo1-xO6 solid solution and roles in photocatalytic degradation of gaseous toluene under visible-light irradiation