Tribocatalytic Degradation of Organic Pollutants Using Fe<sub>2</sub>O<sub>3</sub> Nanoparticles
Haimiao Yu, Jie Fu, Xiaoting Zhu, Zeyu Zhao, Xiaohui Sui, Shiyu Sun, Xiaoqing He, Yongcheng Zhang, Wanneng Ye
Abstract
Tribocatalysts possessing advantages of high performance, eco-friendliness, and low cost also without causing secondary pollution are ideally and highly desirable for practical applications but remain challenging. Here, we demonstrate that eco-friendly and low-cost Fe 2 O 3 nanoparticles exhibit superior tribocatalytic performance through harvesting low-frequency mechanical energy. Rhodamine B (RhB) is completely degraded by Fe 2 O 3 nanoparticles within 15 h under low-frequency magnetic stirring, and the catalytic efficiencies are always maintained above 96% during five consecutive cycles. Systematical experimental explorations indicate that the tribocatalytic performance of Fe 2 O 3 can be improved by increasing the stirring speed and friction area, and the tribocatalytic activity is significantly enhanced under ultrasonic vibration. The friction between Fe 2 O 3 nanoparticles and the magnetic rod and Fe 2 O 3 and the glass cup bottom plays key roles in the degradation of RhB, while the friction between Fe 2 O 3 and water also makes a weak contribution. Catalytic mechanism investigations reveal that the friction-generated positive charges directly decompose dyes, but electrons first react with oxygen to generate superoxide ( • O 2 – ) radicals, and then • O 2 – participates in the degradation of dyes. This work expands the range of tribocatalysts and demonstrates that Fe 2 O 3 is advantageous for its eco-friendliness, low cost, and high performance, which can act as a tribocatalyst for organic pollutant degradation through mechanical friction.