Dye-sensitized solar cells (DSSCs) have emerged as a promising alternative in photovoltaic energy, owing to their efficiency, cost-effectiveness, and versatility. Sensitizers are crucial in efficiently converting solar energy into electricity in these systems. This review focuses on employing coumarins, a class of aromatic organic compounds, as sensitizers in DSSCs. We address the synthesis of coumarins, their photophysical and electronic properties, and their application in optimizing the energy conversion efficiency of DSSCs. We explore the molecular engineering strategies used to improve the properties of coumarins, including structural modification and the combination with other materials. Furthermore, we discuss current challenges and prospects for the development of DSSCs using coumarins as sensitizers. This review aims to provide a comprehensive overview of the current state and future directions of this exciting area of solar energy research.

This paper highlights the complexity and urgency of addressing plastic pollution, drawing attention to the environmental challenges posed by improperly discarded plastics. Petroleum-based plastic polymers, with their remarkable range of physical properties, have revolutionized industries worldwide. Their versatility—from flexible to rigid and hydrophilic to hydrophobic—has fueled an ever-growing demand. However, their versatility has also contributed to a massive global waste problem as plastics pervade virtually every ecosystem, from the depths of oceans to the most remote terrestrial landscapes. Plastic pollution manifests not just as visible waste—such as fishing nets, bottles, and garbage bags—but also as microplastics, infiltrating food chains and freshwater sources. This crisis is exacerbated by the unsustainable linear model of plastic production and consumption, which prioritizes convenience over long-term environmental health. The mismanagement of plastic waste not only pollutes ecosystems but also releases greenhouse gases like carbon dioxide during degradation and incineration, thereby complicating efforts to achieve global climate and sustainability goals. Given that mechanical recycling only addresses a fraction of macroplastics, innovative approaches are needed to improve this process. Methods like pyrolysis and hydrogenolysis offer promising solutions by enabling the chemical transformation and depolymerization of plastics into reusable materials or valuable chemical feedstocks. These advanced recycling methods can support a circular economy by reducing waste and creating high-value products. In this article, the focus on pyrolysis and hydrogenolysis underscores the need to move beyond traditional recycling. These methods exemplify the potential for science and technology to mitigate plastic pollution while aligning with sustainability objectives. Recent advances in the pyrolysis and hydrogenolysis of polyolefins focus on their potential for advanced recycling, breaking down plastics at a molecular level to create feedstocks for new products or fuels. Pyrolysis produces pyrolysis oil and syngas, with applications in renewable energy and chemicals. However, some challenges of this process include scalability, feedstock variety, and standardization, as well as environmental concerns about emissions. Companies like Shell and ExxonMobil are investing heavily to overcome these barriers and improve recycling efficiencies. By leveraging these transformative strategies, we can reimagine the lifecycle of plastics and address one of the most pressing environmental challenges of our time. This review updates the knowledge of the fields of pyrolysis and hydrogenolysis of plastics derived from polyolefins based on the most recent works available in the literature, highlighting the techniques used, the types of products obtained, and the highest yields.

Micro- and nanoplastic (MNP) particles are constantly formed through plastic fragmentation by sunlight, friction, or oxidation. MNPs potentialize health risks when entering the human body by ingestion, infusion, inhalation, and skin absorption. Still, the translocation among intracellular compartments must also be considered because MNPs can reach the circulatory system and be found in virtually all body fluids, tissues, and organs, potentially causing significant health impacts. The ability of MNPs to interact with macromolecules and cause damage to intracellular structures results in several physiopathological conditions, such as inflammation, oxidative imbalance, apoptosis, and carcinogenesis. One major challenge in MNP research is the development of reliable detection and quantification methods and effective sample separation processes. Although there is evidence directly linking MNPs to heart disease, the same cannot be said for diseases such as cancer, respiratory conditions, and reproductive system disorders. Therefore, the impact of MNPs on human health was examined, and a careful evaluation of their effects was carried out. We reviewed the extensive scientific literature from the past years, focusing on exposure, aging, interactions, and effects on entering MNPs into human metabolism and the physiological systems, which makes these particles particularly hazardous.

Herein, we report a direct diazenylation of active methylene compounds that is environmentally friendly, cost-effective, and scalable, utilizing a heterogeneous TiO₂ catalyst that is both accessible and recyclable. The scope of this transformation shows excellent compatibility with both electron-rich and electron-poor diazonium salts, yielding the desired products in very good yields at room temperature.

This review explores both the positive and negative impacts of chemistry on society, focusing on the intersection between pharmaceutical, natural, and synthetic chemicals. On the one hand, drugs developed through medicinal chemistry have saved lives, improved people’s quality of life, and increased longevity. However, they also pose risks, including fatalities and environmental damage. Pharmaceutical chemistry has revolutionized medical practice by enabling the treatment and cure of fatal or debilitating diseases, significantly contributing to the rise in global life expectancy through the research and development of new bioactive substances. This article also highlights the harmful effects of toxic synthetic substances, which negatively impact human health and the environment, affecting plants, animals, air, water, soil, and food.

An environmentally friendly, cheap, and scalable protocol for direct lawsone O-alkylation employing different alcohols using acid chitosan (CS-SO₃H) as a heterogeneous organocatalyst is described herein for the first time. A wide variety of alcohols can be converted with wide functional group tolerance and high atomic economy. Significantly, catalyst recycling and method chemoselectivity were also assessed.