Sustainable hybrid thermo-hygroelectric nanogenerator from ceramic waste: A circular, low-cost solution for decentralized renewable energy

• Hybrid nanogenerator from ceramic waste and iron nanoparticles. • Operates via combined thermal and moisture-induced electricity generation. • Achieves 1.4 V, 23.3 μA, and 13.08 μW/m² at 98°C water stimulus. • 90% energy conversion efficiency with 1.29–7.06 years lifespan. • Low-cost, low-energy fabrication using the polyol method. • Promotes circular economy through industrial waste valorization. The transition to a low-carbon future demands sustainable, scalable, and cost-effective energy technologies that minimize environmental impact while valorizing industrial residues. This study reports the development of a hybrid thermo-hygroelectric nanogenerator integrating iron nanoparticles and red ceramic waste within a functional cementitious matrix, designed for decentralized renewable energy harvesting. The device operates via combined thermal and moisture-induced mechanisms, achieving a maximum output of 1.4 V, 23.3 μA, and 32.7 μW, corresponding to a power density of 13.08 μW/m² when stimulated with water at 98°C. Materials were synthesized via the polyol method and characterized by XRD, XPS, and XAS, confirming the formation of mixed-valence iron oxides embedded in a silica- and calcium-rich support. Circularity is achieved through the reuse of abundant ceramic waste, while the fabrication process is low-energy and easily scalable. The device exhibited energy conversion efficiencies above 90% and an estimated operational lifespan of 1.29–7.06 years, supporting applications in off-grid environmental sensing and low-power electronics. This work demonstrates a sustainable pathway to transform industrial residues into functional energy materials, advancing the circular economy and contributing to cleaner production practices.