Synergetic experimental and DFT insights of energy band structures and photogenerated reactive intermediates are indispensable to design impurity-doped photocatalysts for photocatalytic environment remediation and solar fuels. Herein, despite the larger bandgap (Eg), Zn-doped BiOBr samples exhibited superior activity to BiOBr in the photocatalytic water splitting but adverse in photodegradation of Rhodamine B under visible-light illumination. Based on the spectral and electrochemical impedance characterisations and DFT simulations, the broader bandgap of Zn-doped BiOBr was explicitly assigned to more positive valence band maximum (VBM) and more negative conduction band minimum (CBM). The enhanced photocatalytic water splitting on Zn-doped BiOBr was assigned to the higher redox chemical potentials of charge carriers on respective CBM and VBM, suppressed back reaction and reduced recombination of photogenerated charge carriers. However, the reduced e-h + recombination on Zn-doped BiOBr cannot cancel the adverse influences of its weaker light absorption and dye-sensitisation effects, leading to slower RhB photodegradation.

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Flexible paper-like semiconductor nanowire materials are expected to meet the criteria for some emerging applications, such as components of flexible solar cells, electrical batteries, supercapacitors, nanocomposites, bendable or wearable electronic or optoelectronic components, and so on. As a new generation of wide-bandgap semiconductors and reinforcements in composites, SiC nanowires have advantages in power electronic applications and nanofiber reinforced ceramic composites. Herein, free-standing SiC nanowire paper consisting of ultralong single-crystalline SiC nanowires was prepared through a facile vacuum filtration approach. The ultralong SiC nanowires were synthesized by a sol-gel and carbothermal reduction method. The flexible paper composed of SiC nanowires is ∼100 nm in width and up to several hundreds of micrometers in length. The nanowires are intertwisted with each other to form a three-dimensional network-like structure. SiC nanowire paper exhibits high flexibility and strong mechanical stability. The refractory performance and thermal stability of SiC nanowire paper were also investigated. The paper not only exhibits excellent nonflammability in fire, but also remains well preserved without visible damage when it is heated in an electric oven at a high temperature (1000 °C) for 3 h. With its high flexibility, excellent nonflammability, and high thermal stability, the free-standing SiC nanowire paper may have the potential to improve the ablation resistance of high temperature ceramic composites.