Photocatalytic Degradation of Methylene Blue by TiO2- Graphene Composite

Inappropriate treatments of discharge wastewater from textile industries effluents with high concentrated dye are dangerous to the human and aquatic life due to the carcinogenic effect and chemical toxicity. Therefore, the usage of TiO2 photocatalysis in water treatment has shown a significant impact on the degradation of dye into less carcinogenic and toxicity of the water. Interestingly, the addition of graphene oxide into TiO2 system showed better photocatalytic efficiency of dye degradation as compared toTiO2 photocatalyst alone due to a sufficient amount of radicals supply by the graphene oxide. The oxide radicals reacted with the dye radicals and eliminate the possibility of any chances of recombination of photons and electrons during the photodegradation process. These immobilized graphene/TiO2 films were coated onto the glass substrate under the influence of polymeric polyvinyl aceatate/ polyvinyl chloride (PVA/PVC) mixture act as a binder. The adhesion strength of the immobilized system was fixed at ratio 1:0.025 of PVA/PVC binders. As a result, the immobilized system showed a high degradation rate of methylene blue dye due to the improvement of charge separation and also good adhesion property and sustainability of the film during continuous wastewater treatment.

Degradation behaviour of magnesium alloy and its composite used as a biomaterial

In the last six decades, it has been made a great advancement in the field of engineering material especially in biomaterials, including metal alloys, composites, polymers, ceramics, and metallic glasses. Different form of these biomaterial are used as a engrafts. Unlike conventional materials such as stainless steel, cobalt, or titanium-based alloy resulting in stress shielding effect, some of these materials are designed in such a way to degrade or to be resorbed inside the body rather than removing the implant after its function is served. Here, Magnesium based biomaterials are the most suitable and used as a newly developed biodegradable material. Inherent mechanical properties of magnesium like properties of elastic and modulus rigidity which are very much same as to those of human bone, make it biocompatible. There is limited use of pure Mg due to its corrosive nature, but when formed an alloy or the composite the degradation property can be improved and making them a material of choice for implantation. This paper aim is to review the degradation rate and the methods to control it. Due to high degradation rate of the Mg, as compare to other biomaterials, our final goal is to maintain the balance between the gradual loss of material and mechanical strength during degradation, by providing the strength to the newly forming bone tissue. Mg-based alloy or composite has the potential to be used as a biomaterial without the need for a second surgery, once this goal is achieved.

UV-Accelerated Photocatalytic Degradation of Pesticide over Magnetite and Cobalt Ferrite Decorated Graphene Oxide Composite

Pesticides are one of the main organic pollutants as they are highly toxic and extensively used worldwide. The reclamation of wastewater containing pesticides is of utmost importance. For this purpose, GO-doped metal ferrites (GO-Fe3O4 and GO-CoFe2O4) were prepared and characterized using scanning electron microscopy, X-ray diffraction and Fourier transform infrared spectroscopic techniques. Photocatalytic potentials of catalysts were investigated against acetamiprid’s degradation. A detailed review of the parametric study revealed that efficiency of overall Fenton’s process relies on the combined effects of contributing factors, i.e., pH, initial oxidant concentration, catalyst dose, contact time, and acetamiprid load. ~97 and ~90% degradation of the acetamiprid was achieved by GO-CoFe2O4 and GO-Fe3O4, respectively during the first hour under UV radiations at optimized reaction conditions. At optimized conditions (i.e., pH:3, [H2O2]: 14.5 mM (for Fe3O4, GO-Fe3O4, and GO-CoFe2O4) and 21.75 mM (for CoFe2O4), catalysts: 100 mgL−1, time: 60min) the catalysts exhibited excellent performance, with high degradation rate, magnetic power, easy recovery at the end, and efficient reusability (up to 5 cycles without any considerable loss in catalytic activity). A high magnetic character offers its easy separation from aqueous systems using an external magnet. Moreover, the combined effects of experimental variables were assessed simultaneously and justified using response surface methodology (RSM).

Ag2O and NiO Decorated CuFe2O4 with Enhanced Photocatalytic Performance to Improve the Degradation Efficiency of Methylene Blue

Dye wastewater is a serious threat to human health and life. It is an important task for researchers to treat it efficiently. Among many treatment methods, the photo-Fenton method can rapidly degrade organic pollutants. In this study, a ternary photocatalyst, Ag2O-NiO/CuFe2O4, was prepared and applied for a photo-Fenton reaction to degrade methylene blue (MB). MB had the best degradation effect when 10 mg of the catalyst were used in an 80 mL reaction system for measurement. The degradation rate of MB was up to 96.67% in 60 min with a high degradation rate constant k=5.67×10−2min−1. The total organic carbon (TOC) degradation rate was 78.64% with a TOC degradation rate constant of k=2.57×10−2min−1. Therefore, this study fully proves that Ag2O-NiO/CuFe2O4 can catalyze the photo-Fenton reaction and effectively degrade MB.

Effect of Sintering Temperature on Morphology, Mechanical Properties and Degradation Rate of Magnesium Alloy as Biodegradable Material

Mg-alloy has possibility to be used as biodegradable biomaterial. The main problem in application of this material is high degradation rate. The aim of this research is to study the mechanical, morphology and the degradation properties of Mg-alloy biodegradable by variation of sintering temperature of 500 °C, 550 °C, and 600 °C. Morphology was investigated using SEM-EDX. Phase identification was carried out by XRD and mechanical qualities test was measured by compressive and hardness test. Degradation rate test was assessed by weight loss test. The outcomes show that Mg–Zn– Cu sample with sintering temperature 600 °C is the optimum result. The compressive strength is 175,14 MPa, the hardness value is 410,59 MPa, and degradation rate is 8,57 cm/year.

Fabrication of metal-free PTET-T-COOH/g-C3N4 heterostructure for enhancing photocatalytic activity

The metal-free PTET-T-COOH/g-C3N4 heterostructure exhibits a high degradation rate for RhB under visible light irradiation.

Enhanced piezo-photocatalytic performance by piezoelectric and visible light photoexcitation coupling through piezoelectric Na0.5Bi0.5TiO3 micron crystals

The Na0.5Bi0.5TiO3 with wide band gap exhibits high degradation rate for RhB under ultrasonic vibration and visible light irradiation.

Magnesium Enhances Osteogenesis of BMSCs by Tuning Osteoimmunomodulation

In the process of bone tissue engineering, the osteoimmunomodulatory property of biomaterials is very important for osteogenic differentiation of stem cells, which determines the outcome of bone regeneration. Magnesium (Mg) is a biodegradable, biocompatible metal that has osteoconductive properties and has been regarded as a promising bone biomaterial. However, the high degradation rate of Mg leads to excessive inflammation, thereby restricting its application in bone tissue engineering. Importantly, different coatings or magnesium alloys have been utilized to lower the rate of degradation. In fact, a prior study proved that β-TCP coating of Mg scaffolds can modulate the osteoimmunomodulatory properties of Mg-based biomaterials and create a favorable immune microenvironment for osteogenesis. However, the osteoimmunomodulatory properties of Mg ions themselves have not been explored yet. In this study, the osteoimmunomodulatory properties of Mg ions with involvement of macrophages and bone marrow stem cells (BMSCs) were systematically investigated. Microscale Mg ions (100 mg/L) were found to possess osteoimmunomodulatory properties that favor bone formation. Specifically, microscale Mg ions induced M2 phenotype changes of macrophages and the release of anti-inflammatory cytokines by inhibiting the TLR-NF-κB signaling pathway. Microscale Mg ions also stimulated the expression of osteoinductive molecules in macrophages while Mg ions/macrophage-conditioned medium promoted osteogenesis of BMSCs through the BMP/SMAD signaling pathway. These findings indicate that manipulating Mg ion concentration can endow the Mg biomaterial with favorable osteoimmunomodulatory properties, thereby providing fundamental evidence for improving and modifying the effect of Mg-based bone biomaterials.