Cognitive radio-empowered wireless communication is expected to play a crucial job in the 5G-supported Internet of Things (IoT). Given immense number of resource-constrained IoT devices, which are envisioned to rise in future, there is a need to have these devices connected wirelessly without creating much load on the available spectrum. Cognitive radio (CR) focuses on the efficient utilization of the available spectrum. Incorporating the features of CR in the 5G-enabled IoT devices can help address the spectrum underutilization problem. One of cognitive radio's important features for efficient utilization of the spectrum is spectrum sensing, which involves efficiently identifying unoccupied portions of the spectrum. In this chapter, we will review the features added to the system by the incorporation of cognitive radio capability in the 5G-enabled IoT devices. The addition of sensing capability in the IoT devices will not create any burden on the existing infrastructure (i.e., available spectrum). We will discuss the various types of spectrums sensing algorithms that can be used with IoT devices to identify the unused part of the spectrum. The advantages and limitations of these algorithms will also be explored in relation to IoT devices. The various challenges in different scenarios and future possible directions will also be suggested. The novelty of this work presented here lies in underscoring the effectiveness and significance of these spectrum sensing techniques in enhancing the performance and scalability of cognitive radio-enabled IoT systems without creating load on the available spectrum.