Pd nanoparticles incorporated porous silicon/V^sub 2^O^sub 5^ nanopillars and their enhanced p-type NO^sub 2^-sensing properties at room temperature

A novel room temperature (RT, 25 °C) NO2 gas sensor by utilizing porous silicon (PSi)/V2O5 nanopillars (VONPs) decorated with Pd nanoparticles as sensitive materials was successfully synthesized via a facile methods that reduction of a Pd solution followed by thermal annealing of V film on PSi substrate. The NO2-sensing analysis revealed that the PSi/VONPs-Pd showed obviously enhanced response and selectivity towards NO2, as compared to PSi/VONPs and Si/VONPs. The maximum response of PSi/VONPs-Pd sensor was performed at RT, therefore it has great potential to be used as a RT NO2 gas sensor in practical. The mechanism of gas sensing and enhanced gas response of PSi/VONPs-Pd was discussed.