Energy storage and photosensitivity of in-situ formed silver-copper (Ag-Cu) heterogeneous nanoparticles generated using multi-tool micro electro discharge machining process

Abstract The present work focused on the energy storage and photosensitivity of in-situ formed segregated type silver-copper (Ag-Cu) heterogeneous nanoparticles generated by using the developed Micro-Electro Discharge Machining (Micro-EDM) process. The investigation includes analysis of useful heat gain, temperature gain, and thermal efficiencies by the nanofluids using fabricated mini parabolic solar trough collector. Photosensitivity of nanoparticles are studied by evaluating light absorbance and bandgap energies at different light intensities. Theoretical study includes understanding of the effects of the metallic vapor pressure, dielectric temperature, and the material properties on heterogeneous particle formation mechanisms. The experimentation work comprises of conduction of ten experiments by keeping silver plate (workpiece) at anode terminal and varying copper multi-tool pins from 1, 2, 3…10 at cathode terminal submerged in deionized water with 0.7 mM concentration of CTAB surfactant. Particles generated are found to be well dispersed, heterogeneously arranged structures with average particle size ranging from (4.83 ± 3.35 in 3rd experiment) nm to (15.37 ± 5.46 in 5th experiment) nm. XRD crystallographic studies confirmed the presence of the FCC structure of Ag and BCC structure of Cu2O. The maximum particle synthesis is from the 9th experiment producing 5.4 g/L for 30 min. of machining with the spark energy of 2.88 mJ. The highest useful heat gain is obtained by the 3rd experiment due to higher silver content whereas highest overall thermal efficiency of 14.5% and bandgap energy of 2.75 eV is obtained by the 7th experiment nanofluid.