Work

Tribocatalytic degradation of cationic dyes using Na₀.₄K₀.₁Bi₀.₅TiO₃: influence of friction pair materials and reactive species

Year: 2026

Type: article

Abstract: This study explores the tribocatalytic activity of cationic dyes (Rhodamine B (RhB) and Methylene Blue (MB)) using Na 0.4 K 0.1 Bi 0.5 TiO 3 ( NKBT) as a catalyst under various conditions. The degradation efficiencies of RhB, MB, and binary (RhB + MB) dyes were examined, revealing that RhB exhibited higher degradation (~ 90%) compared to MB (~ 44%) at 600 rpm over 360 min. However, in the binary dye system, MB degraded more (~ 53%) than RhB (~ 9%), contrary to the results of individual dye degradation. The observed results may be attributed to the steric hindrance caused by the planar structure of MB molecules, which interferes with the Coulombic attraction between RhB dye and the catalyst surface, thereby reducing the degradation efficiency of RhB dye. Kinetic analysis showed rate constants of 0.00684 min − 1 , 0.00142 min − 1 , 0.00022 min − 1 , and 0.00208 min − 1 for RhB, MB, binary RhB, and binary MB, respectively. The effect of different friction pairs on RhB dye degradation was studied using polytetrafluoroethylene (PTFE) disc (homemade) with glass, polypropylene (PP), and PTFE beakers. The PTFE beaker-PTFE disc pair showed the highest degradation (~ 93%), followed by PP-PTFE (~ 89%) and glass-PTFE (~ 77%) at 600 rpm over 180 min. Optimal RhB dye degradation (~ 96%) was achieved in the PTFE beaker at 1000 rpm within 120 min.

Source: Scientific Reports

DOI: 10.1038/s41598-026-69891-8