Phase transition dependence of the efficiency of LiZnSbO4 microparticles as tribocatalysts for water remediation.

Tribocatalysis is regarded as a green and efficient advanced oxidation technology for organic wastewater purification, yet the rational design of high-efficiency tribocatalysts remains a major bottleneck, restricting its practical application. In this work, phase-tunable LiZnSbO4 microparticles were synthesized via a facile calcination method, and their phase-dependent tribocatalytic performance was comprehensively evaluated by the degradation of rhodamine B (RhB). The crystalline phase, bandgap width and specific surface area of LiZnSbO4 are precisely modulated by calcination temperature, yielding two typical phases: orthorhombic α-LiZnSbO4 and monoclinic β-LiZnSbO4, verified by XRD analysis. Systematic experiments demonstrate a strong correlation between the crystal structure and tribocatalytic activity of LiZnSbO4; monoclinic β-LiZnSbO4 shows markedly enhanced tribocatalytic activity over orthorhombic α-LiZnSbO4. Owing to the synergistic advantages of high crystallinity and narrow bandgap, the optimized β-LiZnSbO4 achieves a 90% degradation ratio for 5 mg L-1 RhB solution under magnetic stirring at 600 rpm for 8 h. EPR and quenching tests proved that ˙OH acted as the primary active substance, outperforming the contributions of ˙O2- and hvb+. Furthermore, a potential tribodegradation mechanism of RhB is proposed. This work highlights the decisive role of phase engineering in optimizing tribocatalytic behavior and offers a new insight into the controllable construction of high-efficiency tribocatalysts for organic pollutant elimination.