Synthesis of metal nanoparticles using plant extracts is one of the most simple, convenient, economical, and environmentally friendly methods that mitigate the involvement of toxic chemicals. Hence, in recent years, several eco-friendly processes for the rapid synthesis of silver nanoparticles have been reported using aqueous extracts of plant parts such as the leaf, bark, roots, etc. This review summarizes and elaborates the new findings in this research domain of the green synthesis of silver nanoparticles (AgNPs) using different plant extracts and their potential applications as antimicrobial agents covering the literature since 2015. While highlighting the recently used different plants for the synthesis of highly efficient antimicrobial green AgNPs, we aim to provide a systematic in-depth discussion on the possible influence of the phytochemicals and their concentrations in the plants extracts, extraction solvent, and extraction temperature, as well as reaction temperature, pH, reaction time, and concentration of precursor on the size, shape and stability of the produced AgNPs. Exhaustive details of the plausible mechanism of the interaction of AgNPs with the cell wall of microbes, leading to cell death, and high antimicrobial activities have also been elaborated. The shape and size-dependent antimicrobial activities of the biogenic AgNPs and the enhanced antimicrobial activities by synergetic interaction of AgNPs with known commercial antibiotic drugs have also been comprehensively detailed.

One of the most crucial attributes of synthetic organic chemistry is to design organic reactions under the facets of green chemistry for the sustainable production of chemicals. Thus, due to the intensified environmental and safety concern, the need for new technologies for conducting chemical transformation has grown. In this regard, there is enormous interest in the use of heterogeneous catalysts as they generally avoid the generation of waste, require fewer toxic reagents, as well as entail easier separation and recycling of the catalyst. α,β-Unsaturated acids have been widely used in various industrial applications and have been identified as one of the most promising chemicals obtained via the Knoevenagel condensation reaction. This review aims to discuss the most pertinent heterogeneous catalytic systems such as zeolites, mesoporous silica, ionic liquids, metal oxides, and graphitic carbon nitride-based catalysts in the Knoevenagel reaction. Ultimately, this review focuses not only on the catalyst but also provides an overall idea and guide for the preparation of new catalysts with outstanding properties by looking at the chemical and engineering aspects such as the reaction conditions and the mechanisms.

Starch-based edible packaging films have emerged as a sustainable alternative to conventional plastics due to their biodegradable nature, low cost, and abundance. Recent innovations focus on overcoming limitations such as low mechanical strength, moisture sensitivity, and limited barrier properties. Incorporating nanomaterials like cellulose nanofibers and montmorillonite has significantly improved mechanical and barrier properties. Composite films combining starch with biopolymers like chitosan and PVA have enhanced flexibility and antimicrobial capabilities, making them ideal for food packaging. Advances in active and intelligent packaging are transforming these films into multifunctional solutions. For instance, films infused with natural extracts such as clove oil exhibit antimicrobial properties, while pH-sensitive indicators provide real-time food freshness monitoring. Emerging technologies like 3D printing and reactive extrusion enable tailored film designs while utilizing agricultural waste as raw material to enhance sustainability. These advancements make starch-based films pivotal in addressing environmental concerns and meet evolving consumer demands for eco-friendly packaging solutions, though challenges in industrial scalability and cost-effectiveness remain.

Mercury contamination is one of the major environmental and health issues that has been affecting our lives for several decades. To address this matter, a rational design of robust adsorbent materials bearing chelating sites for binding with Hg²⁺ is highly desirable. Porous organic materials have recently emerged as excellent adsorbent materials for heavy metal ions and toxic gases. These porous nanomaterials are generally synthesized via bottom-up chemical reactions, which offer ample opportunities for modifying their structure through the incorporation of various functional sites, thereby, rendering them as an essential platform for designing flexible materials with numerous applications. Scalable synthetic approaches, together with high specific surface area and robustness of framework distinguishes porous organic materials, such as porous organic polymers (POPs) and covalent organic frameworks (COFs), as versatile and indispensable nanoscale materials along with other frontline porous materials including porous carbons, zeolites, aluminophosphates, metal–organic frameworks (MOFs), functionalized mesoporous silica, and periodic mesoporous organosilicas (PMOs). It is worthy to mention that a tailorable structural design approach of POPs and COFs offer adjustable surface property in terms of specific surface area, pore size, and functionality, which can be advantageous towards achieving a benchmark adsorbent material for the detoxification of wastewater to counter harmful environmental effects. Although POPs/COFs are outstanding in removing mercury from contaminated water, to the best of our knowledge, till date, there is hardly any comprehensive review that exclusively highlights all such discoveries. In this review, we highlight some major achievements in the synthesis of porous organic materials and their potential as adsorbents for the removal of Hg(II) from different water resources including actual conditions together with their future potential in water purification technologies.