Synthesis and Enhanced Light Photocatalytic Activity of Modulating Band BiOBrXI1-X Nanosheets

The photocatalysis technique has been proven to be a promising method to solve environmental pollution in situations of energy shortage, and has been intensively investigated in the field of pollutant degradation. In this work, a band structure-controlled solid solution of BiOBr_XI_1−X (x = 0.00, 0.05, 0.10, 0.15, 0.20, 1.00) with highly efficient light-driven photocatalytic activities was successfully synthesized via simple solvothermal methods. The phase composition, crystal structure, morphology, internal molecular vibration, optical properties, and energy band structure were characterized and analyzed by XRD, SEM, HRTEM, XPS, Raman, and UV Vis DRS. To evaluate the photocatalytic activity of BiOBr_XI_1−X, rhodamine B was selected as an organic pollutant. In particular, BiOBr_0.15I_0.85 displayed significantly enhanced photocatalytic activity by virtue of modulating the energy band position, optimizing redox potentials, and accelerating carrier separation. Moreover, the enhancement mechanism was elucidated on the basis of band structure engineering, which provides ideas for the design of highly active photocatalysts for practical application in the fields of environmental issues and energy conservation.

Solvent-mediated synthesis of BiOI with a tunable surface structure for effective visible light active photocatalytic removal of Cr(VI) from wastewater

The present study investigated the effect of various solvents on the tunable surface morphology and photocatalytic activity (PCA) of bismuth oxyiodide (BiOI), which could be used for the reduction of Cr(VI) under visible light irradiation (VLI). BiOI samples exhibiting different morphologies, i.e., two-dimensional square-like nanosheet and three-dimensional hierarchical flower-like morphology, were synthesized by a hydro/solvothermal process using different solvents, namely H₂O, MeOH, EtOH, and ethylene glycol (EG). The crystal structure, surface morphology, surface area, light-absorption capability, and recombination rate of the photogenerated charge carriers were examined by X-ray diffraction, scanning electron microscopy, Brunauer-Emmett-Teller analysis, UV-vis diffuse reflectance spectroscopy, photoluminescence, and transient photocurrent analyses, respectively. The BiOI sample fabricated in EG showed excellent photocatalytic efficiency (~99%) for the reduction of Cr(VI) after 90 min under VLI. The enhanced PCA demonstrated that the high surface area and well-structured surface characteristics of flower-like 3D BiOI microspheres played important roles in the photoreduction process. Moreover, a plausible mechanism for the reduction of Cr(VI) over the EG-BiOI photocatalyst was proposed. The results of the PCA evaluation and recycle test revealed that 3D EG-BiOI microspheres could serve as promising materials for the efficient removal of Cr(VI) from wastewater. Additionally, EG-BiOI could be utilized in other environmental remediation processes.

Composite Magnetic Photocatalyst Bi₅O₇I/MnxZn1-xFe₂O₄: Hydrothermal-Roasting Preparation and Excellent Photocatalytic Activity

A new composite magnetic photocatalyst, Bi₅O₇I/Mn_xZn_1-xFe₂O₄, prepared by a hydrothermal-roasting method was studied. The photocatalytic properties of Bi₅O₇I/Mn_xZn_1-xFe₂O₄ were evaluated by degradation of Rhodamine B (RhB) under simulated sunlight irradiation, and the structures and properties were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ultraviolet-visible light (UV-Vis) diffuse reflectance spectra (DRS), and a vibrating sample magnetometer (VSM). The results indicated that Bi₅O₇I/Mn_xZn_1-xFe₂O₄ was an orthorhombic crystal, which was similar to that observed for Bi₅O₇I. Bi₅O₇I/Mn_xZn_1-xFe₂O₄ consisted of irregularly shaped nanosheets that were 40⁻60 nm thick. The most probable pore size was 24.1 nm and the specific surface area was 7.07 m²/g. Bi₅O₇I/Mn_xZn_1-xFe₂O₄ could absorb both ultraviolet and visible light, and the energy gap value was 3.22 eV. The saturation magnetization, coercivity and residual magnetization of Bi₅O₇I/Mn_xZn_1-xFe₂O₄ were 3.9 emu/g, 126.6 Oe, and 0.7 emu/g respectively, which could help Bi₅O₇I/Mn_xZn_1-xFe₂O₄ be separated and recycled from wastewater under the action of an external magnetic field. The recycling experiments revealed that the average recovery rate of the photocatalyst was 90.1%, and the photocatalytic activity was still more than 81.1% after five cycles.

Soft-templated synthesis of Mn3O4 microdandelions for the degradation of alizarin red under visible light irradiation

A soft-templated strategy has been developed for the synthesis of self-assembled Mn₃O₄ microdandelions that exhibit potential photocatalytic activity towards the degradation of alizarin red under visible light irradiation.

Solvothermal method coupled with thermal decomposition for synthesis of non-stoichiometric BiO1.18I0.64 with excellent photocatalytic activity

Synthesis of non-stoichiometric BiO_1.18I_0.64via a solvothermal method coupled with thermal decomposition.

Synthesis, electron transfer and photocatalytic activity of TiO2 nanotubes sensitized by meso-tetra(4-carboxyphenyl)porphyrin under visible-light irradiation

Porphyrin plays a crucial role in the process of photocatalysis, porphyrin compounds are naturally suitable antennas for solar energy collection and promising direct solar energy-to-chemical conversion equipment.

Enhanced photocatalytic activity of α-Fe2O3/Bi2WO6 heterostructured nanofibers prepared by electrospinning technique

One-dimensional α-Fe₂O₃/Bi₂WO₆ heterostructured nanofibers with the diameter of about 300–500 nm were successfully prepared by using a simple and straightforward protocol combining an electrospinning technique with a sintering process.

Excitation dependent recombination studies on SnO2/TiO2 electrospun nanofibers

SnO₂–TiO₂ electrospun nanofibers and their excitation dependent recombination.

Review of one-dimensional and two-dimensional nanostructured materials for hydrogen generation

Hydrogen is an attractive alternative to fossil fuels in terms of environmental and other advantages.

Biocompatible and biodegradable elastomer/fibrinogen composite electrospun scaffolds for cardiac tissue regeneration

Schematic for nanofiber with HCMs in cardiac tissue engineering.