A piezocatalyst with highly efficient catalytic efficiency toward multiple pollutants’ removal can improve treatment efficiency and reduce the consumption of catalysts, which is ideal for practical applications. Herein, Bi5Ti3FeO15 nanofibers were prepared using electrospinning and its excellent piezocatalytic performances for mixed dyes’ and antibiotics’ degradation were revealed. Rhodamine B (RhB) is degraded by 98% in 20 min, and the acquired reaction rate constant is 0.195 min–1 under ultrasonic vibration. Particularly, the mixed dyes of RhB, acid orange 7, methylene blue, and methyl orange are simultaneously degraded within 40 min, a high rate constant of 0.106 min–1 is achieved, and the degradation efficiencies can be always maintained at ∼100% for five consecutive cycles. The obtained rate constant for mixed dyes’ degradation is superior to many of the previously reported catalysts just toward one dye degradation. Furthermore, it is further demonstrated that tetracycline hydrochloride, bisphenol A, and phenol can be also efficiently degraded by 94, 90, and 79%, respectively, within 30 min. The piezocatalytic performances of nanofibers at different pH values and reaction temperatures were also explored. Catalytic mechanism investigations demonstrate that the optimized Bi5Ti3FeO15 nanofibers possess a weaker carrier recombination rate, smaller carrier transfer resistance, and higher carrier separation efficiency, which account for its superior piezocatalytic performance. This work reveals that Bi5Ti3FeO15 nanofiber is a superior catalyst for organic pollutants’ degradation under mechanical vibration and offers a strategy for the design of other high-performance piezocatalysts.

Piezocatalysis is an emerging and promising catalytic technique for degrading organic pollutants by harvesting mechanical energy. However, the catalytic efficiency and environment compatibility of present piezocatalysts are still unsatisfactory. Here, the superior piezocatalytic performance of eco-friendly poly(tetrafluoroethylene) (PTFE) micron powders was demonstrated by degrading several typical dyes. Methylene blue can be degraded by 99% within 20 min (k = 0.246 min–1) using fresh PTFE under ultrasonic vibration, and PTFE exhibits excellent stability and reusability. In addition, rhodamine B, acid orange 7, and methyl orange can also be degraded by 100, 98, and 99% within 60 min, respectively, demonstrating the wide adaptability of PTFE. Catalytic mechanism investigations demonstrate that •OH and •O2 – play major roles in dye degradation. Furthermore, the influence of various water sources and different containers on the catalytic performances of PTFE was explored, indicating that PTFE has nice environmental suitability and that the glass container facilitates catalytic degradation. Therefore, a designed glass spiral tube was applied for large-volume wastewater purification, which can be further extended for potential applications. This work thus demonstrates that PTFE can be regarded as a promising catalyst for wastewater treatment by harvesting mechanical energy, and the proposed Z-shaped wastewater degradation device has potential applications in wastewater treatment.

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 Fe2O3 nanoparticles exhibit superior tribocatalytic performance through harvesting low-frequency mechanical energy. Rhodamine B (RhB) is completely degraded by Fe2O3 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 Fe2O3 can be improved by increasing the stirring speed and friction area, and the tribocatalytic activity is significantly enhanced under ultrasonic vibration. The friction between Fe2O3 nanoparticles and the magnetic rod and Fe2O3 and the glass cup bottom plays key roles in the degradation of RhB, while the friction between Fe2O3 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 (•O2 –) radicals, and then •O2 – participates in the degradation of dyes. This work expands the range of tribocatalysts and demonstrates that Fe2O3 is advantageous for its eco-friendliness, low cost, and high performance, which can act as a tribocatalyst for organic pollutant degradation through mechanical friction.

Migao volatile oil (MVO), a traditional Chinese medicine extract, exerts a curative effect on coronary heart disease (CHD). In this study, gas chromatography-mass spectrometry (GC-MS) was used to determine the fingerprints of 10 MVO batches, and 27 common components were identified. The anti-CHD activities of the different MVOs were determined using ELISA kits, and haematoxylin and eosin staining was used to assess the histopathological injury in myocardial tissues. Three mathematical models were used to analyse multiple bioactive indices, and an anti-CHD-guided spectrum-effect relationship approach was developed to discover MVO quality control (QC) markers. α-phellandrene, p-cymene, 1,8-cineole, linalool, α-terpineol, α-cubebene, α-copaene, α-humulene, dihydroagarofuran, and δ-cadinene all showed good affinity for target proteins connected to CHD, showing their potential as QC markers. Based on the anti-CHD-guided spectrum-effect relationship approach, a bioactive constituent-based holistic QC method was successfully developed for MVO, which could provide a valuable reference for related QC research.