Synthesis of Au:MgO nanoparticles via laser ablation in liquid for H2S and NO2 gas sensor applications

In this study, we used the pulsed laser ablation (PLA) method to make Au:MgO nanoparticles on porous silicon (PS) substrates. The optical characteristics, crystallinity and surface morphology of generated Au:MgO nanoparticles have been investigated with utilizing XRD, TEM, AFM, UV-Vis, PL and fabrication of gas sensors examined at various laser energies. Au:MgO nanoparticles have been manufactured by pulsed laser ablation method (Q-switched) fundamental 1064-nm Nd:YAG, at different laser energies 600, 800 and 1000 mJ and 100 shots, and then sedimentation on surface of PS (porous silicon) layer prepared by photoelectrochemical etching method. The properties of samples are analyzed by XRD (X-ray diffraction), AFM (atomic force microscope) and TEM (transmission electron microscope). The prepared samples were spherical nanoparticles with an average of roughness and diameter 13.4 and 36.76 nm. The production of approximately spherical core- shell of Au:MgO NPs is indicated by TEM with a mean particle size of 10-55 nm. Also the face cubic-centered shape of Au:MgO NPs is revealed by XRD. Eventually, the diversity of running temperature on the sensor sensitivity, recovery times and the time of response for NO2 and H2S gas sensors fabricated from prepared specimens was studied. The maximal sensitivity of Au:MgO NPs/PS excised by laser energy of 800 mJ of NO2 gas was evaluated as 41.1%, while the maximal sensitivity of Au:MgO NPs/PS excised with a pulsed laser of 1000 mJ of H2S gas is much greater compared to NO2 gas.

Automated summary

This study fabricated Au:MgO nanoparticles on porous silicon substrates using pulsed laser ablation method and investigated their optical characteristics, crystallinity, and surface morphology. The gas sensors fabricated from prepared specimens were evaluated for sensitivity, recovery times, and response to NO2 and H2S gases, showing potential for gas sensing applications.