Facile Electrospinning of CeO2/Bi2WO6Heterostructured Nanofibers with Excellent Visible-light-driven Photocatalytic Performance

Electrospun composite nanofibers as novel high-performance and visible-light photocatalysts for removal of environmental pollutants: A review

Environmental pollution caused by industries and human manipulations is coming a serious global challenge. On the other hand, the world is facing an energy crisis caused by population growth. Designing solar-driven photocatalysts which are inspired by the photosynthesis of plant leaves is a fantastic solution to use solar energy as green, available, and unlimited energy containing ∼50% visible light for the removal of environmental pollutants. The polymeric and non-polymeric-based electrospun composite nanofibers (NFs) are as innovative photocatalytic candidates which increase photocatalytic activity and transition from UV light to visible light and overcome the aggregation, photocorrosion, toxicity, and hard recycling and separation of the nanosized powder form of photocatalysts. The composite NFs are fabricated easily by either embedding the photocatalytic agents into the NFs during electrospinning or via their decorating on the surface of NFs post-electrospinning. Polyacrylonitrile-based, tungsten trioxide-based, zinc oxide-based, and titanium dioxide-based composite NFs were revealed as the most reported composite NFs. All the lately investigated electrospun composite NFs indicated long-term stability, high photocatalytic efficiency (∼> 80%) within a short time of light radiation (10-430 min), and high stability after several cycles of use. They were applied in various applications including degradation of dyes/antibiotics, water splitting, wastewater treatment, antibacterial usage, etc. The photogenerated species especially holes, O₂^∙-, and ^.OH were mostly responsible for the photocatalytic mechanism and pathway. The electrospun composite NFs have the potential to use in large-scale productions in condition that their thickness and recycling conditions are optimized, and their toxicity and detaching are resolved.

Enhanced visible light-active CeO2/CuO/Ag2CrO4 ternary heterostructures based on CeO2/CuO nanofiber heterojunctions for the simultaneous degradation of a binary mixture of dyes

CeO₂/CuO/Ag₂CrO₄ composite is fabricated using an electrospinning and precipitation. Also, composite can photodegrade RB and MB under visible light irradiation. CeO₂/CuO/Ag₂CrO₄ can enhanced photocatalytic activity due to formed heterojunction.

A heterojunction photocatalyst constructed by the modification of 2D-CeO2 on 2D-MoS2 nanosheets with enhanced degrading activity

A new 2D/2D heterojunction of MoS₂/CeO₂ is successfully prepared by a facile hydrothermal method.

In situ growth of copper(ii) phthalocyanine-sensitized electrospun CeO2/Bi2MoO6 nanofibers: a highly efficient photoelectrocatalyst towards degradation of tetracycline

Copper(ii) phthalocyanine-sensitized electrospun CeO₂/Bi₂MoO₆ nanofibers (TNCuPc/CeO₂/Bi₂MoO₆ nanofibers) were fabricated and applied as an efficient novel photocatalyst with enhanced photoelectrocatalytic activity.

Phosphorus-doped cerium vanadate nanorods with enhanced photocatalytic activity

CeVO₄-based photocatalysts have been actively studied, but to the best of our knowledge, P-doped CeVO₄ with enhanced photocatalytic activity has not been reported. Herein, novel P-doped CeVO₄ nanorods were synthesized via a facile hydrothermal method. The doped P exists as PO₄ tetrahedron which replaces VO₄ tetrahedron. The crystal size, specific surface area, and light absorption ability of CeVO₄ were tuned after doping CeVO₄ by P. In particular, the separation and transmission efficiency of photogenerated electron-hole pairs were improved due to the internal electric field caused by the large charge density around PO₄ tetrahedron. This conclusion was also confirmed by DFT calculations. The photocatalytic activities of different samples were tested via photodegradation of aqueous organic pollutants, and a feasible mechanism of photocatalytic reaction was proposed.

Highly efficient Zr doped-TiO2/glass fiber photocatalyst and its performance in formaldehyde removal under visible light

Zr-doped-TiO₂ loaded glass fiber (ZT/GF) composite photocatalysts with different Zr/Ti ratios were prepared with a sol-gel process. Zr⁴⁺ can replace Ti⁴⁺ in the TiO₂ lattice, which is conducive to forming the anatase phase and reducing the calcination temperature. The glass fiber carrier was responsible for better dispersion and loading of Zr-doped-TiO₂ particles, improving the applicability of the Zr-doped-TiO₂. The ZT/GF photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV-vis) and Barrett-Joyner-Halenda (BJH). The performance of photocatalysts with different loading was evaluated in formaldehyde degradation under visible light at room temperature. ZT/GF0.2 exhibited the highest activity, with a formaldehyde removal rate as high as 95.14% being observed, which is better than that of the photocatalyst particles alone. The stability of the catalyst was also tested, and ZT/GF exhibited excellent catalytic performance with 94.38% removal efficiency, even after seven uses.

Oxygen-Induced Bi5+-Self-Doped Bi4V2O11 with a p-n Homojunction Toward Promoting the Photocatalytic Performance

Bi⁵⁺-self-doped Bi₄V₂O₁₁ (Bi⁵⁺-BVO) nanotubes with p-n homojunctions are fabricated via an oxygen-induced strategy. Calcinating the as-spun fibers with abundant oxygen plays a pivotal role in achieving Bi⁵⁺ self-doping. Density functional theory calculations and experimental results indicate that Bi⁵⁺ self-doping can narrow the band gap of Bi₄V₂O₁₁, which contributes to enhancing light harvesting. Moreover, Bi⁵⁺ self-doping endows Bi₄V₂O₁₁ with n- and p-type semiconductor characteristics simultaneously, resulting in the construction of p-n homojunctions for retarding rapid electron-hole recombination. Benefiting from these favorable properties, Bi⁵⁺-BVO exhibits a superior photocatalytic performance in contrast to that of pristine Bi₄V₂O₁₁. Furthermore, this is the first report describing the achievement of p-n homojunctions through self-doping, which gives full play to the advantages of self-doping.

Fabrication of porous Fe2O3/PTFE nanofiber membranes and their application as a catalyst for dye degradation

Novel porous polytetrafluoroethylene (PTFE) nanofiber membranes containing Fe₂O₃(Fe₂O₃/PTFE), used as a heterogeneous catalyst, were preparedviaa three-step method by electrospinning, immersion and calcination.