RESUMEN
Increasing water pollution and decreasing energy reserves have emerged as growing concerns for the environment. These pollution are due to the dangerous effects of numerous pollutants on humans and aquatic organisms, such as hydrocarbons, biphenyls, pesticides, dyes, pharmaceuticals, and metal ions. On the other hand, the need for a clean environment, finding alternatives to fossil and renewable fuels is very important. Hydrogen (H2) is regarded as a viable and promising substitute for fossil fuels, and a range of methodologies have been devised to generate this particular source of energy. Metal-organic frameworks (MOFs) are a new generation of nanoporous coordination polymers whose crystal structure is composed of the juxtaposition of organic and inorganic constituent units. Due to their flexible nature, regular structure, and high surface area, these materials have attracted much attention for removing various pollutants from water and wastewater, and water splitting. MOFs Z-scheme heterojunctions have been identified as an economical and eco-friendly method for eliminating pollutants from wastewater systems, and producing H2. Their low-cost synthesis and unique properties increase their application in various energy and environment fields. The heterojunctions possess diverse properties, such as exceptional surface area, making them ideal for degradation and separation. The development and formulation of Z-scheme heterojunctions photocatalytic systems using MOFs, which possess stable and potent redox capability, have emerged as a successful approach for addressing environmental pollution and energy shortages in recent times. Through the utilization of the benefits offered by MOFs Z-scheme heterojunctions photocatalysts, such as efficient separation and migration of charge carriers, extensive spectrum of light absorption, among other advantages, notable enhancements can be attained. This review encompasses the synthesis techniques, structure, and properties of MOFs Z-scheme heterojunctions, and their extensive use in treating various wastewaters, including dyes, pharmaceuticals, and heavy metals, and water splitting. Also, it provides an overview of the mechanisms, pathways, and various theoretical and practical aspects for MOFs Z-scheme heterojunctions. Finally, it thoroughly assesses existing challenges and suggests further research on the promising applications of MOFs Z-scheme in industrial-scale wastewater treatment.
RESUMEN
AIM AND OBJECTIVE: Chromene derivatives are privileged heterocyclic systems that exhibit various types of biological properties such as antioxidant, anticancer, antimicrobial, hypotensive, and local anesthetic. Cadmium sulfide nanoparticles (CdS NPs) as an efficient heterogeneous catalyst is used in various organic transformations because of its certain unique and unusual physico-chemical properties. The effectiveness of catalytic activity of CdS NPs can be improved due to the combined effect of Ag particles. RESULTS: Ag/CdS nanocomposite is a readily available, recyclable, and non-toxic catalyst used for the highly efficient synthesis of novel 8-aryl-8H-[1,3]dioxolo[4,5-g]chromrne-6-carboxylic acids. This reaction is conveniently performed under mild reaction conditions. All synthesized compounds were well characterized by their satisfactory elemental analyses, IR, 1H and 13C NMR spectroscopy. The synthesized catalyst was fully characterized by XRD, SEM, and EDX techniques. MATERIALS AND METHODS: The present methodology focuses on the condensation reaction of arylmethylidenepyruvic acids with 3,4-methylenedioxyphenol, using a catalytic amount of Ag/CdS nanocomposite (15 mol%) in aqueous media at room temperature to afford 8-aryl-8H-[1,3]dioxolo [4,5-g]chromrne-6-carboxylic acids in high yields (90-97%) within short reaction times (2-4 h). The Ag/CdS nanocomposite was also prepared by an ultrasonic-assisted sol-gel method. CONCLUSION: In conclusion, we have successfully synthesized novel 8-aryl-8H-[1,3]dioxolo[4,5- g]chromrne-6-carboxylic acid derivatives by the Ag/CdS nanocomposite catalyzed cyclocondensation reaction of arylmethylidenepyruvic acids with 3,4-methylenedioxyphenol under mild reaction conditions. Environmentally benign procedure, high to excellent yields of products, simplicity of operation, and use of readily available and recyclable catalyst are the advantages of this new practical reaction.