SYNTHESIS OF Pd NPs VIA LASER ABLATION IN LIQUID ASSISTED WITH MAGNETIC FIELD ON SILICON NANOSTRUCTURE FOR GAS SENSOR

Abstract

In this work, palladium nanoparticles (Pd NPs) are synthesized by laser ablation in liquid (PLAL) with wavelength 532[Formula: see text]nm (second harmonic Nd:YAG laser) at different laser energies 360, 660, and 800[Formula: see text]mJ with 200 pulses and an electric coil is used to generate a magnetic field. The resulting nanosolution was deposited on the previously prepared PS. The morphological and structural properties of the prepared substrates (Pd NPs/PS) are calculated by X-ray diffraction (XRD) pattern, Atomic Force Microscope (AFM), and Transmission Electron Microscopy (TEM). Their results showed that with the increase in the energy of laser pulse, the average particle size was 30.73, 22.60, and 18.01[Formula: see text]nm. Optical properties of Photoluminescence (PL) spectra show decrease of energy band gap at 2.38, 2.43, and 2.47[Formula: see text]eV with an increase in the energy. The sensitivity of application samples Pd NPs/PS/Si gas sensors for NO2 and H2S gas was also investigated with respect to temperature variations. Pd NPs/PS/Si gas sensors have a maximum sensitivity of NO2 gas around 52.6% at [Formula: see text]C for sample prepared at energy 360[Formula: see text]mJ but the highest sensitivity of H2S gas was 31.2% at [Formula: see text]C for energy of 660[Formula: see text]mJ. The effects of the operating temperature on reaction and recovery durations for various laser ablation energies are also discussed.