Metal oxides have been most widely used for developing commercial gas sensors for various applications including environmental monitoring, leakage detection, diagnosing diseases, food safety, etc. However, they suffer from high operating temperatures, poor selectivity, high power consumption, and less portability. Over the last decade, researchers have discovered several new materials for developing high-performance gas sensors. Among these alternatives, two-dimensional (2D) materials find prime importance due to their inherited chemical, physical, and electronic properties. Therefore, in this article, we present a comprehensive review of gas sensors beyond metal oxides particularly focusing on 2D materials. We have systematically discussed the structures, sensing mechanisms, and functionalities of various kinds of recently developed gas sensors. We have also addressed some of the advanced techniques for improving the performance of gas sensors. Finally, we summarize the article by providing the challenges faced by gas sensing technology and opportunities for their future development.

金属氧化物最广泛地用于开发商业气体传感器，用于环境监测、泄漏检测、疾病诊断、食品安全等各种应用。然而，它们存在工作温度高、选择性差、功耗高和便携性差的问题。在过去的十年中，研究人员发现了几种用于开发高性能气体传感器的新材料。在这些替代材料中，二维 (2D) 材料因其继承的化学、物理和电子特性而显得尤为重要。因此，在本文中，我们对金属氧化物以外的气体传感器进行了全面回顾，特别关注二维材料。我们系统地讨论了最近开发的各种气体传感器的结构、传感机制和功能。我们还讨论了一些提高气体传感器性能的先进技术。最后，我们总结了本文，提供了气体传感技术面临的挑战及其未来发展的机遇。