Enhanced Photodegradation in Metal Oxide Nanowires with Co-Doped Surfaces under a Low Magnetic Field

Abstract

This work demonstrated the enhanced photodegradation (PD) resulting from Co-rich doping of ZnO nanowire (NW) surfaces (Co2+/ZnO NWs) prepared by combining Co sputtering on ZnO NWs and immersion in deionized water to exploit the hydrophilic–hydrophobic transitions on the ZnO surfaces resulting from Co atom diffusion. Because of the controllable spin-dependent density of states (DOS) induced by Co2+, the PD of methylene blue dye can be enhanced by approximately 90% (when compared with bare ZnO NWs) by using a conventional permanent magnet with a relatively low magnetic field strength of approximately 0.15 T. The reliability of spin polarization–modulation attained through surface doping, based on the magnetic response observed from X-ray absorption measurements and magnetic circular dichroism, provides an opportunity to create highly efficient catalysts by engineering surfaces and tailoring their spin-dependent DOS.

Manipulating Ferroelectric Polarization and Spin Polarization of 2D CuInP2S6 Crystals for Photocatalytic CO2 Reduction

“…Introducing specific dopants or modifying the surface of the photocatalysts with spin-active species can promote spin polarization. Doping with transition metal ions is a common approach to achieve this goal. , Also, vacancy (or defect) engineering is another strategy to increase unpaired spin electrons and enhance photocatalytic CO 2 reduction. Localized electrons in defect states provide sufficient catalytic activity for the adsorption of water and CO 2 molecules.…”

Spin-Polarized Photocatalytic CO2 Reduction of Mn-Doped Perovskite Nanoplates

“…Moreover, it is well known that the electron spin polarization in semiconductors can be further enhanced by applying an external magnetic field. ,,, Here, an external magnetic field of up to 300 mT is applied to further enhance the photocatalytic performance of Mn-CsPbBr 3 NPLs. A permanent magnet that requires no extra power supply is used as the source of the external magnetic field.…”

High-Efficacy Hierarchical Dy2O3/TiO2 Nanoflower toward Wastewater Reclamation: A Combined Photoelectrochemical and Photocatalytic Strategy

“…Holes undergo an oxidation reaction to generate hydroxyl radicals (·OH), while electrons react with oxygen in the air through a reduction process to produce superoxide radical anions (·O 2 – ). The organic pollutants can be degraded by these active radicals to create H 2 O and CO 2 . − Several strategies have been studied to enhance the photocatalytic efficiency of visible-light photocatalysts, in particular, doping, band gap regulation, structural control, surface sensitization, and phase transfer. − Characteristic features of efficient photocatalysts include photoactivity to biological and chemical matters, nontoxicity, ability to absorb near UV–visible regions, photostability, and cost-effectiveness.…”