Micro and nano plastics in food: A review on the strategies for identification, isolation, and mitigation through photocatalysis, and health risk assessment.

Over the past few years, it has become increasingly evident that microplastic pollutant heavily contaminates water sources, posing a potential threat to both human and wildlife. These plastic pollutants do not get degraded efficiently by natural processes and the existing traditional treatment methods are incapable of fully eradicating them. In this regard, degradation of microplastic contaminants through photocatalytic methods has emerged as a powerful technique. Unfortunately, only a limited number of investigations have been reported in the field of photocatalytic degradation of microplastics. This comprehensive assessment focuses on the detailed analysis of the latest cutting edge engineered technologies aimed at efficiently separating, identifying microplastic contaminants present in food samples and degrading them through photocatalysis. Moreover, detailed information on various instrumental techniques that can be adopted to analyze the isolated micro sized plastic particles has been discussed. The assessment and degradation of these micro contaminants through photocatalytic methods is still in juvenile stage and there are lot of rooms to be explored. The need for profound contemplation on methods to degrade them through photocatalytic approaches as well as their possible health risks to humans motivated us to bring out this review.

Photonic crystal based design of a 3-bit all-optical parity checker and generator for all-optical computing.

Photonic crystal based designs of 3-bit even parity checker and generator circuits are proposed in this paper. These circuits are realized for the first time, to the best of our knowledge, on a photonic crystal platform with the aim of achieving power efficient, simple, and compact devices suitable for photonic integrated circuits. The proposed structures are realized using all-optical reconfigurable XOR/NOT gates with compact dimensions, low power consumption, and high contrast ratios. The operation is based on a linear interference effect leading to reduced power consumptions feasible for operation in the telecommunication wavelength of 1550 nm. The various performance metrics such as contrast ratio, response time, and data rate are analyzed based on simulations using the finite difference time domain technique. All structures achieve small footprints and low response times with operation speeds up to 1 Tbps. The designs are based purely on silicon material, which enables ease of fabrication and offers easy compatibility with existing opto-electronic systems as well as with upcoming all-optical systems. The above circuits have wide applications in optical computing, error correction, detection, and optical cryptography.

Electrical behavior and enhanced photocatalytic activity of (Ag, Ni) co-doped ZnO nanoparticles synthesized from co-precipitation technique.

Methylene blue (MB) dye is the most common harmful, toxic, and non-biodegradable effluent produced by the textile industries. The present study investigates the effect of zinc oxide (ZnO) nanoparticles (NPs) and Ag-Ni doped ZnO NPs on the performance of photocatalytic degradation of MB dye. Pure ZnO and Ag-Ni doped ZnO NPs are synthesized using the co-precipitation method. The crystalline nature and surface morphology of the synthesized pure ZnO and Ag-Ni doped ZnO NPs was characterized by powder X-ray diffraction, scanning electron microscopy (SEM), and high resolution transmission electron microscopy (HRTEM) analysis. The presence of spherical-like morphologies was confirmed from SEM and HRTEM analysis. The presence of Ni-O and Zn-O bands in the synthesized materials was found by Fourier transform infrared (FTIR) spectroscopy analysis. The MB dye was degraded under UV-light exposure in various pH conditions. The Ag (0.02%)-Ni doped ZnO NPs exhibits highest photocatalytic activity of 77% under pH 4.