Efficient Modified Bimetallic Alloy Nanoparticles Porous Silicon Gas Sensors for CO Gas Detection Process

摘要： The influence of embedding Au, Pd monometallic and Au-Pd bimetallic nanoparticles on porous silicon-based gas sensor was investigated. Porous silicon layer P-si was prepared by photo electrochemical etching (PECE) with the laser wavelength of about 635 nm and 25 mW/cm2 laser power density. AuNPs/P-si, PdNPs/P-si and Au-PdNPs/P-si hetrostructures were prepared by ion reduction process, this made by dipping fresh P-si in the salt solution contain HAuCl4, PdCl2 and mixing solutions at ratio 1:1 for about (1.2, 5 and 2 min), respectively. Au NPs/P-si, Pd NPs/P-si and Au-Pd NPs/P-si were investigated by scanning electron microscopy (SEM), FTIR analysis, X-ray diffraction (XRD) and energy dispersive X-ray analysis (EDS). Efficient gas sensing process was recorded for modified porous silicon P-si gas sensor with smallest bimetallic Au-Pd nanoparticles size. Considerable improvement in sensitivity and temporal response were obtained for modified bimetallic alloy nanoparticles porous silicon compared with bare P-si and monometallic nanoparticles gas sensors due to the high specific surface area.