Fast-tracking of NH3 interaction with ZnO nanorods and C/ZnO hybrid nanostructures by operando spectroscopy

Fast X-ray photoemission spectroscopy has been carried out to track the interaction of ammonia gas with hybrid materials based on ZnO nanorods and nanostructured carbon. We provide, for the first time, direct evidence of gas adsorption of ammonia on nanostructured hybrid interfaces combining photoemission with transport measurements through the resistivity change upon gas exposure. This operando methodology allowed us to reconstruct the adsorption isotherms and relate the different behavior to the sample morphology at the nanoscale. While on bare ZnO nanorods, physisorption of ammonia is detected along with photon beam assisted cracking, on the nanostructured carbon the formation of amine groups is detected, without displaying any effect induced by photon beam exposure. Our results make the present experiment an operando general methodology, with the possibility to relate the transport versus dose curves (ultimately the adsorption isotherms) to a specific investigation of the gas/surface interactions.