In this work, we designed the plasmonic photocatalyst of Au–BiOCOOH through a one-pot method, which can be used to effectively treat wastewater contaminated with rhodamine (RhB) and tetracycline (TC). Compared with neat BiOCOOH, as expected, the resulting Au–BiOCOOH illustrated significantly boosted photocatalytic efficiency for degrading RhB and TC under visible light illumination. Remarkably, 3.0%Au–Bi showed the most optimal performance against RhB and TC, achieving degradation rates of 99.5 % and 99.7 % within 120 min. Through multiple characterization techniques, the physical and chemical photoelectric properties of the photocatalyst as well as the photocatalysis mechanism were discussed in detail. UV–visible diffuse reflectance spectroscopy (DRS) analysis demonstrates that the loading of Au nanoparticles (Au NPs) onto 2D nanosheets of BiOCOOH significantly expanded the wavelength range of response of BiOCOOH to visible light. Separately, the outcomes of electrochemical impedance spectroscopy (EIS) and photoluminescence (PL) manifestly reveal that the presence of Au NPs on BiOCOOH can efficiently reduce the interfacial charge transfer resistance and accelerate the photogenerated charge transfer. The free radical trapping test provided evidence for the essential role played by holes (h + ) and superoxide radicals (·O 2 − ) were involved in the degradation of RhB. The study provided a possibility to improve the photocatalytic efficiency of BiOCOOH.
Wenhua Ji,Mingming Zhang,Tao Wang,Xiao Wang,Zhenjia Zheng,Junjie Gong
In this research, the successfully developed molecularly imprinted solid-phase extraction (MISPE) method based on SH-Au modified silica gel for Sudan dyes determination has been described. Gold nanoparticles (Au NPs) were organized onto the surface of silica gel through the covalent binding between sulfydryl and Au. Subsequently, molecularly imprinted polymers (MIPs) were prepared via the graft polymerization using Au NPs as the functional monomer . The composition and morphology of MIPs were characterized by X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and thermogravimetric analysis (TG). Binding property was systematically evaluated through adsorption isotherm , adsorption kinetics , and selective recognition capacity. MISPE pretreatment was successfully established after optimizing various parameters. Under optimized conditions, good linearity for six investigated Sudan dyes was ranged from 0.005 to 10.0 μg g −1 (R 2 >0.999) with low limits of detection and quantification (1.5–4.7 and 5.2–15.5 ng g −1 , respectively). The recoveries at three different spiked levels (0.05, 0.5, and 2.0 μg g −1 of each Sudan dye) were ranged from 87.2% to 94.7% with RSD below 6.1% (n=3). The results demonstrated one reliable, sensitive and accurate MISPE pretreatment technique with excellent reproducibility for the determination of six Sudan dyes in chili powder samples.
Eradicating the bacteria on the surface of titanium-based (Ti) implants and optimizing the local immune environment is urgently needed to minimize the clinical implantation failures. Here, an ultrasound (US)-responsive Ti implant aiming at killing bacteria is prepared by building strontium titanate (SrTiO 3 ) nanoarrays on Ti substrate through a multi-step hydrothermal method and the subsequent decoration of Au nanoparticles (Au NPs). As an n-type semiconductor, SrTiO 3 can combine with Au NPs to form a Mott–Schottky heterostructure. The results reveal that the built-in electric field of the M–S heterojunction composed of Au NPs and SrTiO 3 significantly promotes the separation of electrons and holes while reducing the bandgap. Under US irradiation, Au@SrTiO 3 generates a large amount of reactive oxygen species (ROS) to kill bacteria, meanwhile eliminating bacterial biofilms that adhere to the implant surface. Besides, Au NPs accelerate bone remodeling by modulating macrophage polarization toward inflammation-suppressive orientation. Also, SrTiO 3 and Au NPs synergistically directed the osteogenic differentiation. The implantation in vivo shows that continuously optimizing the osteogenic microenvironment can obviously accelerate the osseointegration of Ti implant. Transcriptomic analysis reveals the in vivo pro-osteointegration mechanism of heterostructured Au@SrTiO 3 nanoarrays on Ti implant.
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