  The sixth generation (6G) wireless communication networks are envisioned to
revolutionize customer services and applications via the Internet of Things
(IoT) towards a future of fully intelligent and autonomous systems. In this
article, we explore the emerging opportunities brought by 6G technologies in
IoT networks and applications, by conducting a holistic survey on the
convergence of 6G and IoT. We first shed light on some of the most fundamental
6G technologies that are expected to empower future IoT networks, including
edge intelligence, reconfigurable intelligent surfaces,
space-air-ground-underwater communications, Terahertz communications, massive
ultra-reliable and low-latency communications, and blockchain. Particularly,
compared to the other related survey papers, we provide an in-depth discussion
of the roles of 6G in a wide range of prospective IoT applications via five key
domains, namely Healthcare Internet of Things, Vehicular Internet of Things and
Autonomous Driving, Unmanned Aerial Vehicles, Satellite Internet of Things, and
Industrial Internet of Things. Finally, we highlight interesting research
challenges and point out potential directions to spur further research in this
promising area.
