Solar energy enhanced tribocatalytic dye degradation using high entropy perovskite ceramics

High-entropy ceramics (HECs) are a novel class of materials distinguished by their multi-principal element scheme forming single-phase structures. These materials have gathered significant attention due to their unique combination of properties, making them promising candidates for various structural and functional applications. While HECs have shown potential in diverse catalytic applications, their utilization in pollutant degradation catalysis remains relatively unexplored. This study investigates the tribocatalytic activity of a high-entropy perovskite ceramic (HEPC) BKNBCT (Bi_0.2K_0.2Na_0.2Ba_0.2Ca_0.2)TiO₃, for the degradation of methylene blue (MB) dye, a common pollutant in environmental studies. The HEPC was synthesized via a relatively simple and economical solid-state reaction method. Tribocatalytic experiments were conducted under dark conditions, UV light, and under solar irradiation, with varying stirring speeds to investigate the effect of mechanical energy. The results demonstrate significantly enhanced degradation of MB dye under photo-tribo catalytic (>80 %) and solar-tribo conditions (>90 %) compared to tribocatalysis alone (∼70 %) within 3 h. This study highlights the potential of utilizing readily available mechanical and solar energy for efficient and sustainable wastewater treatment. The proposed degradation mechanism involves a synergistic interplay of triboelectric charging, electron transfer, and electron-hole pair generation within the HEPC, resulting in the formation of reactive oxygen species that oxidize the dye.