Mitigation of pollutants by chitosan/metallic oxide photocatalyst: A review
TL;DR: In this paper, the authors highlight the potential application of Chitosan (CS) as support materials in photocatalyst system, focusing on mitigation, degradation and mineralization of different ranged pollutants in wastewater.
About: This article is published in Journal of Cleaner Production.The article was published on 2020-07-10. It has received 63 citations till now. The article focuses on the topics: Photocatalysis.
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TL;DR: This work reviews the synthesis and applications of biopolymeric nanomaterials for photocatalytic degradation of azo dyes, and focuses on conducting biopolymers incorporating metal, metal oxide, metal/metal oxide and metal sulphide for improved biodegradation.
Abstract: Pure and drinkable water will be rarer and more expensive as the result of pollution induced by industrialisation, urbanisation and population growth. Among the numerous sources of water pollution, the textile industry has become a major issue because effluents containing dyes are often released in natural water bodies. For instance, about two years are needed to biodegrade dye-derived, carcinogenic aromatic amines, in sediments. Classical remediation methods based upon physicochemical reactions are costly and still generate sludges that contain amine residues. Nonetheless, recent research shows that nanomaterials containing biopolymers are promising to degrade organic pollutants by photocatalysis. Here, we review the synthesis and applications of biopolymeric nanomaterials for photocatalytic degradation of azo dyes. We focus on conducting biopolymers incorporating metal, metal oxide, metal/metal oxide and metal sulphide for improved biodegradation. Biopolymers can be obtained from microorganisms, plants and animals. Unlike fossil-fuel-derived polymers, biopolymers are carbon neutral and thus sustainable in the context of global warming. Biopolymers are often biodegradable and biocompatible.
108 citations
Cites background from "Mitigation of pollutants by chitosa..."
...In addition, chitosan allows quick and trouble-free recovery of the photocatalyst, which can be recycled with or without any regeneration (Adnan et al. 2020)....
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TL;DR: In this article, a base magnetic crosslinked chitosan-glyoxal/ZnO/Fe3O4 composite (CS-G/Fe 3O4) was synthesized and further developed by loading zinc oxide nanoparticles into its polymeric matrix.
91 citations
TL;DR: O-doped g-C3N4 (denoted as x-OCN) materials were prepared by calcining dried the mixtures of urea impregnated with H2O2 at 550°C.
60 citations
TL;DR: It was confirmed that the prepared nanomaterials have the best antifungal agent as compared to the standard antibiotics.
41 citations
TL;DR: In this paper, Fe-La oxides coloaded with MgO (Fe-La/MgO) nanosheets were prepared for the adsorption of methyl orange and phosphate in single and binary systems.
Abstract: Fe-La oxides co-loaded MgO (Fe-La/MgO) nanosheets were prepared for the adsorption of methyl orange and phosphate in single and binary systems The Fe-La oxides content, concentration ratio of methyl orange to phosphate, inorganic ions, and pH values greatly affect the competitive adsorption performance of Fe-La/MgO in binary system Among these obtained Fe-La/MgO composites, Fe-La/MgO-2 with a total Fe-La oxides content of 40 wt% and a Fe/La molar ratio of 1:1 presents the best adsorption capacity of phosphate (3882 mg g−1) within 120 min, and La2O3/MgO with a La2O3 content of 20 wt% exhibits the highest adsorption activity of methyl orange (3038 mg g−1) within 40 min in single system However, the adsorption capacities of Fe-La/MgO-2 for phosphate and methyl orange in binary system are respectively 3951 mg g-1 and 1652 mg g−1 within 40 min due to the competitive adsorption between phosphate and methyl orange The low pH is favorable for the separation of phosphate and methyl orange in binary system Langmuir isotherm and second-order model can well fit with the adsorption isotherms and kinetics in single system In addition, these adsorption processes of Fe-La/MgO-2 for methyl orange and phosphate in single system are the physisorption and chemisorption governed by the intra-particle diffusion and external mass transfer, respectively
31 citations
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TL;DR: In this paper, the potential of hot electrons in metallic structures and its potential as an alternative to conventional electron-hole separation in semiconductor devices are discussed along with challenges in terms of the materials, architectures and fabrication methods.
Abstract: Optical generation of hot electrons in metallic structures and its potential as an alternative to conventional electron–hole separation in semiconductor devices are reviewed. The possibilities for realizing high conversion efficiencies with low fabrication costs are discussed along with challenges in terms of the materials, architectures and fabrication methods
2,237 citations
TL;DR: In this paper, a review of the literature on nanocarbon-TiO2 photocatalysts is presented, highlighting recent progress in the development of carbon dioxide photocatalyst.
1,075 citations
TL;DR: In this paper, a review of the research and application of heterogeneous semiconductor photocatalysis for the treatment of low-level concentrations of pollutants in water and air using titanium dioxide as a “model” semiconductor.
Abstract: Semiconductor heterogeneous photocatalysis, the subject of this review, is a versatile, low-cost and environmentally benign treatment technology for a host of pollutants. These may be of biological, organic and inorganic in origin within water and air. The efficient and successful application of photocatalysis demands that the pollutant, the catalyst and source of illumination are in close proximity or contact with each other. The ability of advanced oxidation technology to remove low levels of persistent organic pollutants as well as microorganisms in water has been widely demonstrated and, progressively, the technology is now being commercialized in many areas of the world including developing nations. This review considers recent developments in the research and application of heterogeneous semiconductor photocatalysis for the treatment of low-level concentrations of pollutants in water and air using titanium dioxide as a “model” semiconductor. The review considers charge transport characteristics on the semiconductor surface, photocatalyst reactor design and organic degradation mechanistic pathways. The effects of photoreactor operating parameters on the photocatalytic process are discussed in addition to mineralization and disinfection kinetics.
995 citations
TL;DR: Ultrafast spectroscopy studies revealed that there is significant electron-hole recombination within the first few picoseconds, while Sn doping and the change of surface morphology have no major effect on the ultrafast dynamics of the charge carriers on thepicosecond time scales.
Abstract: We report on the synthesis and characterization of Sn-doped hematite nanowires and nanocorals as well as their implementation as photoanodes for photoelectrochemical water splitting. The hematite nanowires were prepared on a fluorine-doped tin oxide (FTO) substrate by a hydrothermal method, followed by high temperature sintering in air to incorporate Sn, diffused from the FTO substrate, as a dopant. Sn-doped hematite nanocorals were prepared by the same method, by adding tin(IV) chloride as the Sn precursor. X-ray photoelectron spectroscopy analysis confirms Sn4+ substitution at Fe3+ sites in hematite, and Sn-dopant levels increase with sintering temperature. Sn dopant serves as an electron donor and increases the carrier density of hematite nanostructures. The hematite nanowires sintered at 800 °C yielded a pronounced photocurrent density of 1.24 mA/cm2 at 1.23 V vs RHE, which is the highest value observed for hematite nanowires. In comparison to nanowires, Sn-doped hematite nanocorals exhibit smaller fe...
990 citations
TL;DR: An effective strategy for synthesizing extremely active graphitic carbon nitride (g-C3N4) from a low-cost precursor, urea, is reported, and it was found that as the degree of polymerization increases and the proton concentration decreases, the hydrogen-evolution rate is significantly enhanced.
Abstract: The major challenge of photocatalytic water splitting, the prototypical reaction for the direct production of hydrogen by using solar energy, is to develop low-cost yet highly efficient and stable semiconductor photocatalysts. Herein, an effective strategy for synthesizing extremely active graphitic carbon nitride (g-C3N4) from a low-cost precursor, urea, is reported. The g-C3N4 exhibits an extraordinary hydrogen-evolution rate (ca. 20 000 μmol h−1 g−1 under full arc), which leads to a high turnover number (TON) of over 641 after 6 h. The reaction proceeds for more than 30 h without activity loss and results in an internal quantum yield of 26.5 % under visible light, which is nearly an order of magnitude higher than that observed for any other existing g-C3N4 photocatalysts. Furthermore, it was found by experimental analysis and DFT calculations that as the degree of polymerization increases and the proton concentration decreases, the hydrogen-evolution rate is significantly enhanced.
978 citations