A novel gas microsensor combining SnO₂ submicron/nanostructured porous sensitive film with Micro-Electro-Mechanical systems (MEMS) microheater was successfully fabricated. The film was made of hierarchically mixed Pd/SnO₂ (HM-PTO) composites composed of Pd/SnO₂ hollow submicrospheres (Pd/SnO₂-HSs) and Pd/SnO₂ nanoparticles (Pd/SnO₂-NPs) deposited on the microheater platform using the microdispensing method. The as-prepared HM-PTO sensors exhibited high sensitivities, fast response/recovery rates, good selectivity, reliable reversibility, and relevant stability towards ethanol at low power consumption. The resulting superior sensing performances were attributed to the unique hierarchical structure. The internal void architecture of Pd/SnO₂-HSs provided large specific surface areas, proper mesopore size distribution, large number of active adsorption/interaction sites, as well as promoted the chemisorption and dissociation of gas molecules due Pd-doping to yield superior gas response. In particular, the nano-sized SnO₂ particles ensured the uniform deposition of the materials to yield enhanced local conductivities, and possibly faster phase transfer reactions responsible for the extremely good response/recovery performance. This simple fabrication procedure combined with high sensing performances look promising for the development of hierarchical morphologies of novel materials for gas sensing applications.

中文翻译：

---

用于低功率乙醇气体传感器的高效分层Pd / SnO ₂混合多孔结构沉积微加热器

成功地制造了一种将SnO ₂亚微米/纳米结构的多孔敏感膜与微机电系统（MEMS）微型加热器结合起来的新型气体微传感器。该膜由分层混合的Pd / SnO ₂（HM-PTO）复合材料制成，该复合材料由Pd / SnO ₂空心亚微球（Pd / SnO ₂ -HSs）和Pd / SnO ₂纳米颗粒（Pd / SnO ₂-NPs）使用微分配方法沉积在微加热器平台上。所制备的HM-PTO传感器具有高灵敏度，快速响应/回收率，良好的选择性，可靠的可逆性以及在低功耗下对乙醇的相关稳定性。产生的出色的传感性能归因于独特的层次结构。Pd / SnO ₂ -HSs的内部空隙结构提供了大的比表面积，适当的中孔尺寸分布，大量的活性吸附/相互作用位点，并促进了由于Pd掺杂而产生的气体分子的化学吸附和解离，从而产生了优异的气体回复。尤其是纳米级的SnO ₂颗粒确保了材料的均匀沉积，从而提高了局部电导率，并且可能实现了更快的相转移反应，从而实现了极佳的响应/恢复性能。这种简单的制造程序与高感测性能相结合，对于开发用于气体感测应用的新型材料的分​​层形态具有广阔的前景。