Recent Advances in Doped Bi2O3 and its Photocatalytic Activity: A Review

Bismuth Oxide (Bi2O3) has a very promising photocatalytic ability to degrade waste pollutants under visible light irradiation because it has a small energy gap of around 2.85-2.58 eV. Although it has excellent potential as a photocatalyst, Bi2O3 has the disadvantage of a high electron-hole pair recombination rate, which will reduce its photocatalytic activity. To overcome these problems, surface modifications, defect recognition, or doping of Bi2O3 are carried out to obtain a more effective and efficient photocatalyst to degrade waste pollutants under visible light irradiation. Several studies by researchers have been described for the modification of Bi2O3 by doping. Various types of doping are given, such as doping in elements or doping in the form of compounds to form composites. Based on several studies that have been described, appropriate doping has been shown to increase the photocatalytic activity of Bi2O3. Keywords: Bi2O3, Photocatalyst, Doping

In-situ hybridization of ZnO nanorod and graphene oxide with enhancing photocatalytic activity

In this work, nanohybridization of ZnO nanorod and graphene oxide (GO) were prepared by a facile hydrothermal method. The effects of GO on crystal structure and surface morphology of ZnO were revealed by Scanning electron microscopy (SEM), Raman, and X-ray diffraction (XRD). The presence of GO in the composite resulted the ZnO nanorod more uniform which its diameter size was decreased. Optical properties characterized by UV-vis diffuse reflectance spectra (DRS) showed that the ZnO/GO composite has the narrower bandgap value and the better visible-light absorption characterisitics in compare to the bare ZnO. As a result, the photocatalytic ability in degradation of methylene blue under solar irradiation was enhanced in the ZnO/GO composite.

Synthesis of C,N,S-tridoped TiO2 distribute onto silicone for photocatalytic on degradation of tetracycline under visible light irradiation

Using carbon, nitrogen, and sulfur sourced from thiourea to co-doped TiO2 (C,N,S-TiO2), was prepared via hydrothermal method using precursors of titanyl sulfate TiOSO4, obtained by decomposition of ilmenite ore in Binh Dinh. The material used to make the substrate is glass and distributed onto it is silicone and photocatalytic. The structure and properties of materials system were investigated by modern physicochemical analysis methods including scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectra, diffuse reflection spectroscopy UV-Vis, transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDX) and nitrogen isothermal adsorption. The photocatalytic ability of materials system after being carried by silicone is demonstrated by decomposing tetracycline (10 mg/L) in aqueous solution with the yield more than 88% efficiency after 6 hours under visible light irradiation. The optimum dose of the photocatalyst was 0.6 g/L under visible light irradiation. The results indicated that C, N, S co-doped TiO2 demonstrated the highest photocatalytic efficiency and a perspective recyclable potential when it is distributed onto silicone.

Preparation and Characterization of Tubelike g-C3N4/Ag3PO4 Heterojunction with Enhanced Visible-Light Photocatalytic Activity

Water pollution caused by dye wastewater is a potential threat to human health. Using photocatalysis technology to deal with dye wastewater has the advantages of strong purification and no secondary pollution, so it is greatly significant to look for new visible-light photocatalysts with high photocatalytic ability for dye wastewater degradation. Semiconductor photocatalyst silver phosphate (Ag3PO4) has high quantum efficiency and photocatalytic degradation activity. However, Ag3PO4 is prone to photoelectron corrosion and becomes unstable during photocatalysis, which severely limits its application in this field. In this study, a tubelike g-C3N4/Ag3PO4 heterojunction was constructed by the chemical precipitation method. An Ag3PO4 nanoparticle was loaded onto the surface of the tubelike g-C3N4, forming close contact. The photocatalytic activity of the photocatalyst was evaluated by the degradation of RhB under visible-light irradiation. The tubelike g-C3N4/Ag3PO4-5% heterojunction exhibited optimal photocatalytic performance. In an optimal process, the degradation rate of the RhB is 90% under visible-light irradiation for 40 min. The recycling experiment showed that there was no apparent decrease in the activity of tubelike g-C3N4/Ag3PO4-5% heterojunction after five consecutive runs. A possible Z-type mechanism is proposed to explain the high activity and stability of the heterojunction.

Tea polyphenol modified, photothermal responsive and ROS generative black phosphorus quantum dots as nanoplatforms for promoting MRSA infected wounds healing in diabetic rats

Background Healing of MRSA (methicillin-resistant Staphylococcus aureus) infected deep burn wounds (MIDBW) in diabetic patients remains an obstacle but is a cutting-edge research problem in clinical science. Surgical debridement and continuous antibiotic use remain the primary clinical treatment for MIDBW. However, suboptimal pharmacokinetics and high doses of antibiotics often cause serious side effects such as fatal complications of drug-resistant bacterial infections. MRSA, which causes wound infection, is currently a bacterium of concern in diabetic wound healing. In more severe cases, it can even lead to amputation of the patient's limb. The development of bioactive nanomaterials that can promote infected wound healing is significant. Results The present work proposed a strategy of using EGCG (Epigallocatechin gallate) modified black phosphorus quantum dots (BPQDs) as therapeutic nanoplatforms for MIDBW to achieve the synergistic functions of NIR (near-infrared)-response, ROS-generation, sterilization, and promoting wound healing. The electron spin resonance results revealed that EGCG-BPQDs@H had a more vital photocatalytic ability to produce singlet oxygen than BPQDs@H. The inhibition results indicated an effective bactericidal rate of 88.6% against MRSA. Molecular biology analysis demonstrated that EGCG-BPQDs significantly upregulated CD31 nearly fourfold and basic fibroblast growth factor (bFGF) nearly twofold, which were beneficial for promoting the proliferation of vascular endothelial cells and skin epidermal cells. Under NIR irradiation, EGCG-BPQDs hydrogel (EGCG-BPQDs@H) treated MIDBW area could rapidly raise temperature up to 55 °C for sterilization. The MIBDW closure rate of rats after 21 days of treatment was 92.4%, much better than that of 61.1% of the control group. The engineered EGCG-BPQDs@H were found to promote MIDBW healing by triggering the PI3K/AKT and ERK1/2 signaling pathways, which could enhance cell proliferation and differentiation. In addition, intravenous circulation experiment showed good biocompatibility of EGCG-BPQDs@H. No significant damage to major organs was observed in rats. Conclusions The obtained results demonstrated that EGCG-BPQDs@H achieved the synergistic functions of photocatalytic property, photothermal effects and promoted wound healing, and are promising multifunctional nanoplatforms for MIDBW healing in diabetics. Graphical Abstract