Sustain. Chem., Volume 5, Issue 2 (June 2024) – 4 articles

Green carbon-based materials (GCM), i.e., carbon materials produced using renewable biomass or recycled waste, ought to be used to make processes sustainable and carbon-neutral. Carbon nanomaterials, like carbon dots and the nanobichar families, and carbon materials, like activated carbon and biochar substances, are sustainable materials with great potential to be used in different technological applications. In this review, the following four applications were selected, and the works published in the last two years (since 2022) were critically reviewed: agriculture, water treatment, energy management, and carbon dioxide reduction and sequestration. GCM improved the performance of the technological applications under revision and played an important role in the sustainability of the processes, contributing to the mitigation of climate change, by reducing emissions and increasing the sequestration of CO₂eq. Full article

Exploring sustainable approaches to replace petroleum-based chemicals is an ongoing challenge in reducing the carbon footprint. Due to the complexity and percentage variation in nature-generated molecules, which further varies based on geographical origin and the purification protocol adopted, a better isolation strategy for individual components is required. Agrowaste from the cashew industry generates phenolic lipid (cardanol)-rich cashew nutshell liquid (CNSL) and has recently shown extensive commercial utility. Cardanol naturally exists as a mixture of three structurally different components with C₁₅-alkylene chains: monoene, diene, and triene. The separation of these three fractions has been a bottleneck and is crucial for certain structural designs and reproducibility. Herein, we describe the gram-scale purification of cardanol into each component using flash column chromatography within the sustainability framework. The solvent used for elution is recovered and reused after each stage (up to 82%), making it a cost-effective and sustainable purification strategy. This simple purification technique replaces the alternative high-temperature vacuum distillation, which requires substantial energy consumption and poses vacuum fluctuation and maintenance challenges. Three components (monoene 42%, diene 22%, and triene 36%) were isolated with good purity and were fully characterized by ¹H and ¹³C NMR, GC-MS, HPLC, and FTIR spectroscopy. The present work demonstrates that greener and simpler strategies pave the way for the isolation of constituents from nature-sourced biochemicals and unleash the potential of CNSL-derived fractions for high-end applications. Full article

An overview of the latest advances in the design of active catalysts with the ability to promote (photo) Fenton processes in water from a Green Chemistry perspective is discussed herein. A critical evaluation of the most relevant advances has been disclosed, and a brief perspective is presented about what is needed to fill the gap of knowledge in this field. Full article

The current economic development paradigm, which is based on steadily rising resource consumption and pollution emissions, is no longer viable in a world with limited resources and ecological capacity. The “green economy” idea has presented this context with a chance to alter how society handles the interplay between the environmental and economic spheres. The related concept of “green nanotechnology” aims to use nano-innovations within the fields of materials science and engineering to generate products and processes that are economically and ecologically sustainable, enabling society to establish and preserve a green economy. Many different economic sectors are anticipated to be impacted by these applications, including those related to corrosion inhibitor nanofertilizers, nanoremediation, biodegradation, heavy metal detection, biofuel, insecticides and pesticides, and catalytic CO₂ reduction. These innovations might make it possible to use non-traditional water sources safely and to create construction materials that are enabled by nanotechnology, improving living and ecological conditions. Therefore, our aim is to highlight how nanotechnology is being used in the green economy and to present promises for nano-applications in this domain. In the end, it emphasizes how critical it is to attain a truly sustainable advancement in nanotechnology. Full article