Nanostructured metal oxide semiconductors have emerged as promising nanoscale photocatalysts due to their excellent photosensitivity, chemical stability, non-toxicity, and biocompatibility. Enhancing the photocatalytic activity of metal oxide is critical in improving their efficiency in radical ion production upon optical exposure for various applications. Therefore, this review paper provides an in-depth analysis of the photocatalytic activity of nanostructured metal oxides, including the photocatalytic mechanism, factors affecting the photocatalytic efficiency, and approaches taken to boost the photocatalytic performance through structure or material modifications. This paper also highlights an overview of the recent applications and discusses the recent advancement of ZnO-based nanocomposite as a promising photocatalytic material for environmental remediation, energy conversion, and biomedical applications.

This paper reports the development of ZnO NRs/rGO-based photocatalysts integrated into a tree-branched polymer-based microfluidic reactor for efficient photodegradation of water contaminants. The reactor system includes a photocatalytic reactor, tree-branched microfluidic channels, and ZnO nanorods (NRs) coated with reduced graphene oxide (rGO) on a glass substrate within an area of 0.6 × 0.6 cm². The ZnO NRs/rGO acts as a photocatalyst layer grown hydrothermally and then spray-coated with rGO. The microfluidic system is made of PDMS and fabricated using soft lithography (micro molding using SU-8 master mold patterned on a silicon wafer). The device geometry is designed using AutoCAD software and the flow properties of the microfluidics are simulated using COMSOL Multiphysics. The microfluidic platform’s photocatalytic process aims to bring the nanostructured photocatalyst into very close proximity to the water flow channel, reducing the interaction time and providing effective purification performance. Our functionality test showed that a degradation efficiency of 23.12 %, within the effective residence time of less than 3 s was obtained.

The escalating threat of multidrug-resistant (MDR) pathogens has intensified the search for alternative antimicrobial strategies, with zinc oxide (ZnO) nanostructures (NSs) emerging as a promising solution due to their unique physicochemical properties. This review critically examines recent advances in the development and application of ZnO NSs as antimicrobial agents, with a focus on addressing the limitations of conventional antibiotics. It highlights the underlying mechanisms of action such as membrane disruption, reactive oxygen species generation, and ion release, and how these are influenced by NS size, morphology, and surface properties. The review also analyses key factors affecting antimicrobial efficacy, including environmental conditions, particle concentration, and synergistic effects with other materials. Applications discussed range from biomedical coatings and wound dressings to food packaging and water purification systems. By outlining current challenges in synthesis optimization, mechanistic understanding, and safety assessment, this review identifies critical knowledge gaps and provides a roadmap for future research. The paper is organized to first introduce the global context of MDR infections, followed by sections on antimicrobial mechanisms, influencing parameters, practical applications, and emerging perspectives in ZnO-based antimicrobial technologies.

This study describes a method by which to synthesize SiO₂-based graphene nanoballs (SGB) using atmospheric pressure chemical vapor deposition (APCVD) with copper vapor assistance. This method should solve the contamination, damage, and high costs associated with silica-based indirect graphene synthesis. The SGB was synthesized using APCVD, which was optimized using the Taguchi method. Multiple synthesis factors were optimized and investigated to find the ideal synthesis condition to grow SGB for thermoelectric (TE) applications. Raman spectra and FESEM-EDX reveal that the graphene formed on the silicon nanoparticles (SNP) is free from copper. The prepared SGB has excellent electrical conductivity (75.0 S/cm), which shows better results than the previous report. Furthermore, the SGB nanofillers in bismuth telluride (Bi₂Te₃) nanocomposites as TE materials exhibit a significant increment in Seebeck coefficients (S) compared to the pure Bi₂Te₃ sample from 109 to 170 μV/K at 400 K, as well as electrical resistivity decrement. This approach would offer a simple strategy to improve the TE performance of commercially available TE materials, which is critical for large-scale industrial applications.