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A facile and green synthesis of silver nanoparticles (AgNPs) by aqueous chitosan solution and microwave irradiation is proposed as a cost effective and environmentally benevolent alternative to chemical and physical methods. With this aim, different amounts of chitosan solution (3–9 ml) with several concentration (4–6% w/v) and 3 ml of the silver salt solution (0.5% w/v) were mixed and microwave irradiated for 100 s. Response surface methodology (RSM) was used to evaluate the effects of the amount and concentration of chitosan solution on the particle size and concentration of the synthesized AgNPs. The optimum AgNPs synthesis process was obtained using 9 ml of 0.4% (w/v) chitosan solution. The spherical and more stable AgNPs synthesized at optimum conditions had particle size, concentration, polydispersity index (PDI) and zeta potential values of 37 nm, 69 ppm, 0.557 and +50 mV, respectively. The synthesized AgNPs indicated strong antifungal activity toward Aspergillus flavus and high antibacterial activity against both Gram-positive (Staphylococcus aureus) and Gram-negative bacteria (Escherichia coli).

Microwave-promoted continuous flow systems have emerged as a game-changer in nanoparticle synthesis. Owing to the excellent compatibility between fast, sustainable microwave heating and one-step, efficient flow chemistry, this promising technology is meant to enhance the synthetic abilities of nanoscientists. This Perspective aims to present a panoramic view of the state of the art in this field. Additionally, the effect of various microwave and flow parameters on the properties of nanoparticles is discussed along with a comparative glance at the features that make flow reactors more practical and sustainable than their batch counterparts. The overview has also analyzed various microwave continuous flow reactors available in the literature, with an acute emphasis on the nanosynthesis route and design features. Moreover, a discussion on the numerical modeling of microwave flow systems has been made a part of this perspective to reiterate its significance and encourage research in this domain. The Perspective also briefly comments on existing challenges and future prospects of this technology.

Graphitic carbon nitride (g‐C3N4) is a metal‐free semiconductor that has been widely regarded as a promising candidate for sustainable energy production or storage. In recent years, g‐C3N4 has become the center of attention by virtue of its impressive properties, such as being inexpensive, easily fabricable, nontoxic, highly stable, and environment friendly. Herein, the recent research developments related to g‐C3N4 are outlined, which sheds light on its future prospective. Various synthetic methods and their impact on the properties of g‐C3N4 are detailed, along with discussion on frequently used characterization methods. Different approaches for g‐C3N4 surface functionalization, mainly categorized under covalent and noncovalent strategies, are outlined. Moreover, the processing methods of g‐C3N4, such as g‐C3N4‐based thin films, hierarchical, and hybrid structures, are explored. Next, compared with the extensively studied energy‐related applications of the modified g‐C3N4s, relatively less‐examined areas, such as environmental and sensing, are presented. By highlighting the strong potential of these materials and the existing research gaps, new researchers are encouraged to produce functional g‐C3N4‐based materials using diverse surface modification and processing routes.

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