Boosting the high gas sensing performance via laser embedding Schottky heterointerfaces at particle boundaries in SnO2 nanofibers

Metal oxide semiconductor-based gas sensors often require noble metals for modification to enhance the carrier mobility of the material. However, current noble metal modifications are almost always performed at the ma-terial surface, making it difficult to apply them to the particle boundaries (PBs) of the material, which can greatly reduce the utilization of noble metals. We herein synthesized Pt nanocrystals (NCs) with average size of 1 nm by the technology of pulsed laser irradiation, followed by in situ embedded at the PBs of SnO2 nanofibers to address the unwanted carrier loss at PBs for substantially improved gas sensing. The Pt NCs/SnO2 exhibited 2.23-fold enhancement of response values, and 2.86-fold improvement on selectivity for NO2 at 50 degrees C, comparing to these samples without PBs engineering. Further analysis showed that the enhancement of the gas-sensitive performance is mainly due to the electronic and chemical sensitization of Pt NCs at the SnO2 PBs and the high utilization of Pt NCs leading to a significant increase in the carrier mobility of the material. We thus believe present work provides an efficient alternative for developing high performance gas sensing based on materials with intrinsic particle boundaries.