Ni-Co₃O₄@CoPW复合材料的制备及传感特性的研究

Study on the Preparation and Sensing Properties of Ni-Co₃O₄@CoPW Composites

摘要: 针对呼出气异戊二烯实时检测中面临的响应/恢复时间长与灵敏度受限问题，研究提出了一种基于活性调控与功能壳层协同的改性策略。利用共沉淀、自组装刻蚀和热处理三步法，成功制备了掺杂不同Ni浓度(1 mol%、2 mol%、3 mol%、4 mol%、5 mol%)的Ni-Co₃O₄@CoPW蛋黄–壳复合材料。研究结果表明，Ni²⁺的掺杂有效调控了材料的电子结构并诱导产生了丰富的氧空位；同时，独特的蛋黄–壳结构发挥了协同作用，显著增强了气敏性能。其中，3% Ni-Co₃O₄@CoPW传感器对50 ppm异戊二烯的响应值高达412.07 (20% RH)，响应与恢复时间大幅缩短至43 s和110 s (较未改性材料分别缩短了108 s和28 s)。最后，分析了电子结构调制与界面催化的协同增效机制，为开发用于无创疾病筛查的高性能呼气分析传感器提供了新的设计思路。

Abstract: To address the issues of long response/recovery times and limited sensitivity in the real-time detection of exhaled isoprene, this study proposes a modification strategy based on the synergy of activity regulation and functional shells. Ni-Co₃O₄@CoPW yolk-shell composites with different Ni doping concentrations (1 mol%, 2 mol%, 3 mol%, 4 mol%, and 5 mol%) were successfully prepared via a three-step method comprising coprecipitation, self-assembly etching, and heat treatment. The results indicate that Ni²⁺ doping effectively modulates the electronic structure of the material and induces abundant oxygen vacancies. Meanwhile, the unique yolk-shell structure exerts a synergistic effect, significantly enhancing the gas-sensing performance. Specifically, the 3% Ni-Co₃O₄@CoPW sensor exhibits a high response of 412.07 to 50 ppm isoprene (at 20% RH). Its response and recovery times are drastically shortened to 43 s and 110 s, which are 108 s and 28 s shorter than those of the pristine material, respectively. Finally, the synergistic enhancement mechanism of electronic structure modulation and interfacial catalysis is analyzed. This work provides a new design strategy for developing high-performance breath-analysis sensors for non-invasive disease screening.