Room-temperature gas sensors based on low-dimensional nanomaterials

Recent atmospheric pollution which is mainly caused by an ever-increasing population, industrial gas waste, vehicle exhaust emissions, and indiscriminate burning of garbage has become a serious problem for the modern natural environment. It is necessary to continuously detect these gas pollutants and monitor toxic gases to prevent environmental deterioration. Room-temperature gas sensors have attracted considerable attention in the current gas sensor industry because of advantages such as low power consumption, great stability and simple manufacturing processes for low-cost sensor systems, smart electronics, and specifically Internet of Things (IoT) platforms. In particular, new emerging low-dimensional nanomaterials play a critical role in enhancing sensing properties owing to their unique structure and remarkable electronic, mechanical, and optical characteristics. This review presents the recent state-of-the art development of room-temperature gas sensor technologies based on low-dimensional nanomaterials. Various nanostructure materials such as 0D, 1D, and 2D nanomaterials are widely introduced and essential investigations of external stimuli methods including voltage biasing and light stimulation for driving gas sensing performance without relying on high temperature are fully covered. Finally, various device applications and recent developments including wearable gas sensors, machine learning and neuromorphic olfactory devices are discussed and future prospects and perspectives on the challenges and opportunities of room-temperature gas sensors based on low-dimensional nanomaterials are also provided.