<p>With the increasing demand for clean, renewable and sustainable energy solutions, triboelectric nanogenerators (TENGs), as emerging devices that convert mechanical energy into electrical energy through triboelectric effect and electrostatic induction, have attracted a lot of attentions. TENGs have become a very promising technology and found a wide range of applications from powering wearable electronics to building large-scale energy harvesting system. In this context, here we present a state-of-art review of TENGs, commencing with the basic working mechanism and the materials and device architectures responsible for TENG operation. We discuss strategies to improve their performance ranging from material selection, through surface engineering to structural design. Moreover, we emphasize their fate of sustainable applications, including environmental monitoring, self-powered sensors, and wearable technologies that could play a role in future energy sustainability goals. In spite of this potential, issues of durability, scalability and feasibility of production are still key barriers to any kind of mainstream adoption. Industrial considerations and real-world implementations are also reviewed in this review, providing an idea of the current state of the TENG technology. As the last point, we offer a visionary look at the future of TENGs and their role in the sustainability of energy sources and solutions to the current global energy issues. TENGs have the potential to become major contributors in a prospective sustainable energy era, particularly with the support of the advancement of innovative solutions to current limitations.</p>