Green synthesis of nanoparticles has gained enormous attention in today's world due to ongoing demand to develop safe, sustainable, cost-effective and environmentally friendly process for synthesizing a wide variety of materials including metal/metal oxides nanoparticles, hybrid and bioinspired materials. In the current study, we have carried out green synthesis of copper oxide (CuO) nanoparticles (NPs) using psidium guajava leaf extract as capping agent and copper acetate as metal precursor. The biosynthesized nanoparticles were characterized using wide variety of techniques i.e. powder X-ray diffraction (PXRD), FTIR, TGA and HRTEM. The PXRD result confirms the synthesis of copper oxide nanoparticles in pure phase having monoclinic symmetry. The average particle size using PXRD was found out to be ~33 nm.

In recent decades, the accumulation and fragmentation of plastics on the surface of the planet have caused several long-term climatic and health risks. Plastic materials, specifically microplastics (MPs; sizes < 5 mm), have gained significant interest in the global scientific fraternity due to their bioaccumulation, non-biodegradability, and ecotoxicological effects on living organisms. This study explains how microplastics are generated, transported, and disposed of in the environment based on their sources and physicochemical properties. Additionally, the study also examines the impact of COVID-19 on global plastic waste production. The physical and chemical techniques such as SEM-EDX, PLM, FTIR, Raman, TG-DSC, and GC-MS that are employed for the quantification and identification of MPs are discussed. This paper provides insight into conventional and advanced methods applied for microplastic removal from aquatic systems. The finding of this review helps to gain a deeper understanding of research on the toxicity of microplastics on humans, aquatic organisms, and soil ecosystems. Further, the efforts and measures that have been enforced globally to combat MP waste have been highlighted and need to be explored to reduce its potential risk in the future.

In this article, the effect of interparticle interactions of 4.63 nm sized monolayer protected gold clusters (Au MPCs) during quantized double layer (QDL) charging has been investigated using electrochemical techniques. Voltammetry and scanning tunneling microscopy have been used to compare their electron transfer behavior. Furthermore, since the QDL process is diffusion controlled, the diffusion coefficient values have been estimated at various charge steps using two independent electroanalytical techniques, viz. chronoamperometry and impedance. These results show that higher core charge facilitates higher diffusion coefficient values, and indicate that repulsive interactions dominate for charged MPCs compared to those of its neutral analogue, which are mainly attractive in nature. Additionally, the electron transfer rate constants at various charge steps have been estimated from the impedance results, showing comparatively faster electron transfer rate at higher charge states.