Preparation of Ag-doped Bi5O7I composites with enhanced visible-light-induced photocatalytic performance

Silver-decorated black phosphorus: a synergistic antibacterial strategy

Black phosphorus (BP) exhibits great potential as antibacterial materials due to its unique photocatalytic activity. However, the unsatisfactory optical absorption and quick recombination of photoinduced electron-hole pairs restrain its photocatalytic antibacterial performance. In this work, silver nanoparticles (AgNPs) were decorated on BP to construct BP@AgNPs nanohybrids and then introduced into poly-l-lactic acid scaffold. Combining the tunable bandgap of BP and the LSPR effect of AgNPs, BP@AgNPs nanohybrids displayed the broaden visible light absorption. Furthermore, AgNPs acted as electron acceptors could accelerate charge transfer and suppress electron-hole recombination. Therefore, BP@AgNPs nanohybrids achieved synergistically enhanced photocatalytic antibacterial activity under visible light irradiation. Fluorescence probe experiment verified that BP@AgNPs promoted the generation of reactive oxygen species, which could disrupt bacteria membrane, damage DNA and oxide proteins, and finally lead to bacteria apoptosis. As a result, the scaffold possessed strong antibacterial efficiency with a bactericidal rate of 97% under light irradiation. Moreover, the scaffold also exhibited good cytocompatibility. This work highlighted a new strategy to develop photocatalytic antibacterial scaffold for bone implant application.

Recent advancement in Bi5O7I-based nanocomposites for high performance photocatalysts

Bi₅O₇I belongs to the family of bismuth oxyhalides (BiOX, X = Cl, Br, I), having a unique layered structure with an internal electrostatic field that promotes the separation and transfer of photo-generated charge carriers. Interestingly, Bi₅O₇I exhibits higher thermal stability compared to its other BiOX member compounds and absorption spectrum extended to the visible region. Bi₅O₇I has demonstrated applications in diverse fields such as photocatalytic degradation of various organic pollutants, marine antifouling, etc. Unfortunately, owing to its wide band gap of ∼2.9 eV, its absorption lies mainly in the ultraviolet region, and a tiny portion of absorption lies in the visible region. Due to limited absorption, the photocatalytic performance of pure Bi₅O₇I is still facing challenges. In order to reduce the band gap and increase the light absorption capability of Bi₅O₇I, doping and formation of heterostructure strategies have been employed, which showed promising results in the photocatalytic performance. In addition, the plasmonic heterostructures of Bi₅O₇I were also developed to further boost the efficiency of Bi₅O₇I as a photocatalyst. Here, in this review article, we present such recent efforts made for the advanced development of Bi₅O₇I regarding its synthesis, properties and applications. The strategies for photocatalytic performance enhancement have been discussed in detail. Moreover, in the conclusion section, we have presented the current challenges and discussed possible prospective developments in this field.

ZnO@Bi5O7I Heterojunction Derived from ZIF-8@BiOI for Enhanced Photocatalytic Activity under Visible Light

In the study, ZIF-8@BIOI composites were synthesized by the hydrothermal method and then calcined to acquire the ZnO@Bi₅O₇I composite as a novel composite for the photocatalytic deterioration of the antibiotic tetracycline (TC). The prepared ZnO@Bi₅O₇I composites were physically and chemically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Brunauer-Emmet-Teller (BET) surface area, UV-Vis diffuse reflectance spectroscopy (DRS), emission fluorescence spectra, transient photocurrent response, electrochemical impedance spectra and Mott-Schottky. Among the composites formed an n-n heterojunction, which increased the separation efficiency of electrons and holes and the efficiency of charge transfer. After the photocatalytic degradation test of TC, it showed that ZnO@Bi₅O₇I (2:1) had the best photodegradation effect with an 86.2% removal rate, which provides a new approach to the treatment of antibiotics such as TC in wastewater.

Photocatalytic Performance and Mechanism Research of Ag/HSTiO2 on Degradation of Methyl Orange

The Sol-gel method is successfully used to prepare high specific surface area TiO₂ (HSTiO₂). Then, the photodeposition method is used to composite silver particles with HSTiO₂. X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer-Emmett-Teller, and UV-vis spectroscopy are used to characterize the Ag/HSTiO₂ nanocomposites. It can be concluded that the prepared TiO₂ has a large specific surface area, reaching 125.5 m² g^-1. Additionally, the addition of silver particles successfully broadens the photoresponse range from the UV region to the visible light region. In order to evaluate the photocatalytic activity of Ag/HSTiO₂, we conducted the methyl orange degradation test. The results showed that the photocatalytic activity of the sample is significantly higher than that of pure TiO₂.