The development of modern cutting-edge technology relies heavily on the huge success and advancement of nanotechnology, in which nanomaterials and nanostructures provide the indispensable material cornerstone. Owing to their nanoscale dimensions with possible quantum limit, nanomaterials and nanostructures possess a high surface-to-volume ratio, rich surface/interface effects, and distinct physical and chemical properties compared with their bulk counterparts, leading to the remarkably expanded horizons of their applications. Depending on their degree of spatial quantization, low-dimensional nanomaterials are generally categorized into nanoparticles (0D); nanorods, nanowires, and nanobelts (1D); and atomically thin layered materials (2D). This review article provides a comprehensive guide to low-dimensional nanomaterials and nanostructures. It begins with the classification of nanomaterials, followed by an inclusive account of nanofabrication and characterization. Both top-down and bottom-up fabrication approaches are discussed in detail. Next, various significant applications of low-dimensional nanomaterials are discussed, such as photonics, sensors, catalysis, energy storage, diverse coatings, and various bioapplications. This article would serve as a quick and facile guide for scientists and engineers working in the field of nanotechnology and nanomaterials.

The spray cooling is investigated for a high-temperature steel plate using varying temperature coolant for different nozzle-plate orientations. Before experimentation with very-high mass-flux spray, droplet-train impact assessment indicates liquid film breakup intensification down the inclined plane. The heat transfer analysis suggests a significant cooling performance change with an inclination change at high-temperature coolant. For 50°C coolant usage in horizontal-case, cooling rate, average surface heat flux, critical heat flux, and average heat transfer coefficient are 161°C/s, 2.20 MW/m², 2.62 MW/m², and 3.28 kW/m²K, respectively. The 40°C coolant has a low-performance factor, while 50°C has high cooling performance.

The current work considers mono, mixed SiO2, and CuO nanofluid application in very-high mass-flux spray cooling. At first, the modified sol-gel method based SiO2 and wet-chemical method based CuO nanoparticles are prepared. After that, nanoparticles are characterized for density, surface area, crystalline/amorphous nature, functional groups, compositions, morphology, and particle size. The SiO2 and CuO nanofluid are prepared using one-step and two-step methods, respectively. The nanofluid is characterized for thermophysical properties, particle size distribution, and stability. The applied mono or mixed nanofluid performance is assessed in terms of cooling rate, heat flux, and heat transfer coefficient, estimated using inverse heat conduction analysis. An improvement in cooling rate is observed with concentration enhancement for all nanofluids, owing to thermal conductivity and nucleation site enhancement. However, for mono CuO and mixed SiO2-CuO nanofluid at their highest concentration, the cooling enhancement rate decreases as compared to water, which may be attributed to nucleation sites blockage by high-density CuO excessive deposition. The highest 162 oC/s cooling rate is observed at the highest mixed nanofluid concentration. The average surface heat flux, critical heat flux, and average heat transfer coefficient improvement are maximum at1.68 MW/m2, 2.64 MW/m2, 2.56 kW/m2K, respectively, for mixed nanofluid at their highest concentration.