Based on large specific surface area characteristics of low-dimensional nanomaterials

a method for centrifugal deposition and assembly of nanoparticles films by palladium(Pd)-coated gold(Au)nanobicones is proposed

and a transmission-type optical fiber hydrogen sensor based on the film is designed.Au nanobipyramids are prepared by seed growth method and purified by "over-growth-separation-etching" method to obtain a biconical Au core with a particle diameter of about 12nm.These cores are then coated with palladium to obtain biconical Au-Pd core-shell nanoparticles(Au NBPs@Pd).The characterization and analysis results show that the palladium-coated core-shell nanoparticles formed based on the biconical Au morphology have uniform particle size and good crystallinity.The Au NBPs@Pd are deposited on the glass slide by horizontal centrifugal deposition to obtain nanoparticle film.The hydrogen sensing response characteristics at 4% hydrogen concentration are tested by the constructed transmission type optical fiber hydrogen sensor.The results show that the fastest response time is about 27s in an environment of normal temperature and pressure and hydrogen concentration of 4%

which basically realizes accurate detection at low hydrogen concentration and has a good prospect in the application of hydrogen concentration detection.