Zhang Zhenkai, Chen Qiuying, Guo Yujun, Dastan Davoud, Gao Xiao-Chun, Liu Ying, Tan Xiao-Ming, Wang Feifei, Yin Xi-Tao, Ren Shan, Ma Xiaoguang
School of Physics and Optoelectronic Engineering, Ludong University, Yantai 264000, China.
Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14850, United States.
Langmuir. 2024 Oct 1;40(39):20505-20514. doi: 10.1021/acs.langmuir.4c02052. Epub 2024 Sep 22.
The construction of p-n heterojunctions is expected to be one of the effective means to improve gas sensitivity. In this research, p-n heterojunctions are successfully constructed by metal oxides derived from metal-organic frameworks (MOFs). MOFs-derived bimetallic CoO/SnO microspheres are prepared by precipitation. Gas-sensing performance shows that the CoO/SnO sensor exhibits an extremely high response (/ = 641) to 20 ppm of -butanol at 200 °C, which is 19 times that of pristine SnO. It can detect -butanol gas at low concentrations, has good selectivity to alcohol gas, and reduces the interference of benzene gas. The improved gas sensitivity can be attributed to the formation of a stable heterojunction between CoO and SnO, resulting in a greater resistance change of CoO/SnO. CoO/SnO inherits the characteristic of high specific surface area of MOFs, which provides abundant sites for the reaction of the target gas and oxygen molecules. Finally, the gas-sensing mechanism of the CoO/SnO-based sensor is discussed in detail.
构建p-n异质结有望成为提高气敏性的有效手段之一。在本研究中，通过金属有机框架（MOF）衍生的金属氧化物成功构建了p-n异质结。采用沉淀法制备了MOF衍生的双金属CoO/SnO微球。气敏性能表明，CoO/SnO传感器在200℃下对20 ppm的正丁醇表现出极高的响应（/ = 641），是原始SnO的19倍。它能够检测低浓度的正丁醇气体，对酒精气体具有良好的选择性，并减少了苯气体的干扰。气敏性的提高可归因于CoO和SnO之间形成了稳定的异质结，导致CoO/SnO的电阻变化更大。CoO/SnO继承了MOF高比表面积的特性，为目标气体与氧分子的反应提供了丰富的位点。最后，详细讨论了基于CoO/SnO的传感器的气敏机理。
