自组装单层膜模板控制生长氧化亚铜晶体及其对DMMP气体的检测

摘要

使用了一种在自组装单分子层(SAM)模板衬底上由电化学氧化-还原自发生长的方法,择优取向生长氧化亚铜(Cu2O)微晶.通过扫描电子显微镜和微区XRD等方法对合成的Cu2O晶体进行了形貌和结构表征.结果表明:合成的样品为立方结构的Cu2O晶体,且形貌、取向和颗粒尺寸得到了有效控制,此结果可归结为SAMs对电化学氧化-还原过程的影响和结晶过程中的模板效应.利用该方法,将Cu2O晶体生长于静态式微悬臂梁的表面作为敏感层,制得了一种新型的化学传感器.基于Cu2O晶体表面的Cu(Ⅰ)与DMMP(甲基膦酸二甲酯,沙林模拟剂)分子中的膦酰基团之间存在的配位作用,该传感器可对几十ppb的DMMP重复响应.%With self-assembled monolayer (SAM) as template,cubic cuprous-oxide (Cu2O) crystals with preferred orientation are obtained via simple and effective electrochemical redox process.Micro-region X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to characterize the as-grown Cu2O crystals.Besides uniform morphology and crystal size,the micro-crystals take preferred orientation that is strongly influences by the pre-modified SAM on substrate.The experiments indicate that the SAM not only acts as the growing template for the crystals,but also strongly affects the electrochemical redox process.To explore its sensing properties,the Cu2O crystals were grown onto a micro-cantilever to detect DMMP (dimethyl methylphosphonate) vapor.The sensing mechanism is complexation of phosphonyl group with Cu(I) that generates surface-stress at the cantilever surface.Tens of ppb DMMP vapor is reproducibly detected.