Current Microwave Chemistry - Current Issue

Microwave-assisted extraction (MAE) is a highly efficient technique used to extract bioactive compounds from plant materials. This method is gaining popularity due to its alignment with the principles of sustainable and green chemistry. Microwave radiation selectively heats polar molecules and their solvents, leading to a rapid increase in temperature within the sample.

The MAE method can be performed solvent-free or utilize environmentally friendly solvents (e.g., water, ethanol), thereby reducing environmental pollution. Therefore, the selection of a suitable solvent is the most crucial parameter in an efficient extraction process. Reduced exposure to high temperatures minimizes the degradation of heat-sensitive compounds, resulting in higher-quality extracts.

This process significantly reduces extraction time compared to conventional methods, which typically require longer heating periods. MAE typically yields higher amounts of bioactive compounds in shorter times due to improved cell wall disruption and enhanced solvent penetration.

MAE improves atom economy by enhancing extraction efficiency, leading to less chemical waste. This technique minimizes the generation of hazardous substances during the extraction process.

MAE is considered a green and sustainable technology due to its energy efficiency, reduced solvent usage, enhanced extraction yields, and lower environmental impact.

Microwave technology is widely used in chemical synthesis and offers unique opportunities that are unachievable with the use of conventional methods of heating. This study aims to review the background, methods, and development in microwave-assisted chemistry and advances with a focus on its increasing relevance in various disciplines. Microwave chemistry promises to greatly decrease the time to complete a reaction from hours to minutes, and increase yield and purity all at once.

The rationale for this approach is based on specific patterns in communication, for example, dipolar polarization and ionic mobility that distinguish the effective transfer of energy to molecular systems. Details of these principles are explored and related to synthetic organic chemistry, materials chemistry, and green chemistry. The assessment of microwave-supported processes demonstrates advances in the preparation of heterocycles, medicinal chemistry, and polymer chemistry.

These refined works not only increase the reaction efficiency but also do all this with the help of excluding hazardous reagents for the environment, which is a great idea concerning Sustainable Chemistry. Subsequent advancements of hybrid reactors and the utilization of real-time monitoring enhance the adaptability of microwave technology. Microwave synthetic chemistry in the present context involves nanotechnology and catalysis for the production of multifunctional materials and nanoscale particles. Furthermore, the paper discusses directions in environmental applications, including pollutant degradation and renewable energy systems, so as to demonstrate that the technology is relevant to fighting global issues. However, microwave chemistry comes with certain limitations such as scalability, the problem of non-uniform heating, and the long-term costs of purchasing exotic microwave equipment.

This research also presents a detailed description of these limitations and offers remedies as discussed by creating adaptive microwave systems for system and computational models for reaction optimization. Finally, this work closes with a discussion of potential perspectives for microwave chemistry, ranging from the concept of interdisciplinary approaches and the inclusion of artificial intelligence in reaction design and process monitoring. Because of its revolutionary capability, microwave chemistry is on the verge of revolutionizing the chemical industry.

The preparation of PtNiCo/reduced graphene oxide (RGO) nanocatalysts with excellent activity and stability using a facile, microwave-assisted, and cost-effective synthetic method is crucial for the commercial application of fuel cells and clean energy technologies. This study examines the impact of varying metal ratios on the catalytic properties of PtNiCo/RGO and compares them with those of Pt/RGO.

PtNiCo/RGO nanocatalysts were synthesized via a microwave-assisted hydrothermal method using ethylene glycol as the solvent. Different metal precursor ratios were used to prepare PtNiCo/RGO-1, -2, and -3. The physical and electrochemical characteristics of the synthesized catalysts were analyzed using transmission electron microscopy (TEM), X-ray diffraction (XRD), and various electrochemical tests.

Among the synthesized samples, PtNiCo/RGO-3 demonstrated the best performance, with an electrochemical surface area (ECSA) of 82.61 m²/g, 2.7 times higher than that of Pt/RGO (30.39 m²/g). It also exhibited a lower CO oxidation potential and better stability during electrochemical methanol oxidation. TEM analysis confirmed a thin nanoparticle morphology with average diameters of 2–5 nm.

The enhanced performance of PtNiCo/RGO-3 is attributed to the synergistic effects among Pt, Ni, Co, and the RGO support. These interactions improved electron transfer, dispersion, and resistance to catalyst poisoning.

PtNiCo/RGO-3 demonstrates excellent catalytic activity, anti-poisoning characteristics, and durability, making it a promising electrocatalyst for fuel cells and hydrogen production. This work supports the development of cost-effective and efficient clean energy technologies, aligning with the United Nations Sustainable Development Goal 7 (Affordable and Clean Energy).