A nanohybrid architecture composed of single-wall carbon nanotube films and graphene heterostructures (SWCNT/graphene) was developed as a three-dimensional (3D) electrode. Atomic layer deposition (ALD) was used for conformal coating of catalytic Pt nanoparticles on the 3D ALD-Pt@SWCNT/graphene nanohybrid architecture for further enhancement of H2 sensing, taking advantage of the large sensing area and conformally coated nanostructures of the catalytic Pt. Remarkably, the H2 response was found to be improved by 50% in the SWCNT/graphene nanohybrid, indicating that graphene provides a more efficient charge transport. The ALD-Pt further enhances the H2 responsivity of the 3D ALD-Pt @SWCNT/graphene nanohybrids. By coating 10 cycles of ALD-Pt on the SWCNT/graphene nanohybrid, the H2 response (2.77%) is approximately twice that (1.4%) of its counterpart without the ALD-Pt. By further optimizing the 3D ALD-Pt@SWCNT/graphene nanohybrids with respect to the ALD-Pt cycle numbers and SWCNT film thickness, a H2 responsivity as high as 7.5% was achieved on the SWCNT/graphene nanohybrid sample with a 560 nm thick SWCNT film and 50 cycles of ALD-Pt.
Keywords: atomic layer deposition; hydrogen sensor; nanohybrid; platinum; single-wall carbon nanotubes.