Efficient wide-spectrum one-dimensional MWO₄ (M = Mn, Co, and Cd) photocatalysts: Synthesis, characterization and density functional theory study

Broadening the absorption region to near-infrared (NIR) light is critical for the photocatalysis due to the larger proportion and stronger penetration of NIR light in solar energy. In the present paper, one-dimensional (1D) MWO₄ (M = Mn, Co, and Cd) materials synthesized by electrospinning technique, were studied by combining the density functional theory (DFT) with experiment results, which possessed the enhanced light absorption capability within the range of 200-2000 nm. It was proved that in the ultraviolet-visible (UV-Vis) region, the absorption bands of CoWO₄ and MnWO₄ samples were attributed to the metal-to-metal charge transfer mechanism, while the absorption of CdWO₄ sample may be referable to the ligand-to-metal charge transfer mechanism. In the near-infrared (NIR) region, the absorption of CoWO₄ and MnWO₄ primarily originated from the d-d orbital transitions of Mn²⁺ and Co²⁺. The photocatalytic experimental results showed that the degradation rates for bisphenol A (BPA) over CoWO₄, MnWO₄, and CdWO₄ photocatalysts under UV-Vis/NIR light irradiation for 140 min/12 h were 78.8 %/75.9 %, 23.8 %/21.3 %, 12.8 %/8.7 %, respectively. This research offers the novel insights into the precise construction of tungstate catalytic systems and contributes to the advancement of UV-Vis-NIR full spectrum photocatalytic technology, and lays a foundation for a cleaner and more environmental-friendly future.