近日，中国科学院福建物质结构研究所徐刚及其小组，通过对TiO₂@NH₂-MIL-125界面的能级调谐实现了高性能气体传感功能。相关论文发表在2024年12月5日出版的《德国应用化学》杂志上。

据介绍，金属氧化物化学传感器在环境监测、安全防护、疾病诊断等方面具有巨大的应用潜力。然而，原始MOs的热激活传感机制导致工作温度高，选择性差，这是阻碍实际应用的主要挑战。在MOs的异质结界面上精确调制带结构，提供了解锁独特的电学和光学特性的机会，使它们能够克服这些挑战。具有可调谐结构的MOF是一种很有前途的材料，可用于调整金属有机框架异质结能级。

在该研究中，研究团队报告了MO@MOF异质结的能级结构工程，以优化化学电阻传感性能。通过TiO₂@(NH₂)_x-MIL-125的-NH₂功能化，x分别在0到1和2之间变化时可以灵活地将界面从跨隙调制为交错隙。TiO₂@(NH₂)_x-MIL-125结合了金属氧化物(MOs)和金属有机骨架(MOF)的优点，协同提高了气敏性能。因此，TiO₂@NH₂-MIL-125是第一个在1 ppb下检测NO₂的光活化材料，响应时间为室温下<0.3 min, 并表现出良好的选择性和长期稳定性。他们的研究强调了能量带工程在制造高性能传感器方面的潜力，提供了一种克服当前材料限制的策略。

附：英文原文

Title: Energy-Level  Alignment at TiO2@NH2-MIL-125 Interface for High-Performance Gas Sensing

Author: Wei-Hua Deng, Min-Yi Zhang, Chun-Sen Li, Ming-Shui Yao, Gang Xu

Issue&Volume: 2024-12-05

Abstract: Metal oxide (MO)-based chemiresistive sensors have great potential in environmental monitoring, security protection, and disease diagnosis. However, the thermally activated sensing mechanism in pristine MOs leads to high working temperature and poor selectivity, which are the main challenges impeding practical applications. Precise modulation of the band structure at the heterojunction interfaces of MOs offers the opportunity to unlock unique electrical and optical properties, enabling us to overcome these challenges. Metal–organic frameworks (MOFs) with tunable structures are promising materials for aligning the energy levels at the heterojunctions of MOs. Herein, we report the energy-level structural engineering of MO@MOF heterojunctions to optimize chemiresistive sensing performance. The interface was flexibly modulated from a straddling gap to a staggered gap by –NH2 functionalization of TiO2@(NH2)x-MIL-125, varying x from 0 to 1 and 2, respectively. TiO2@(NH2)x-MIL-125 combines the advantages of MOs and MOFs to synergistically improve gas-sensing properties. As a result, TiO2@NH2-MIL-125 is the first light-activated material to detect NO2 at 1 ppb with a response time of < 0.3 min at room temperature. It also exhibited excellent selectivity and long-term stability. Our study underscores the potential of energy band engineering in creating high-performance sensors, offering a strategy to overcome current material limits.

DOI: 10.1002/anie.202419195

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202419195