Abstract Waste Polyethylene terephthalate plastic bottles were used as precursors to fabricate carbon dots (CDs) via air oxidation and sulfuric acid hydrothermal treatment. Owing to the nano-size effect and abundant acidic groups, CDs allowed their application as a novel solid acid for quasi-homogeneous catalytic dehydration of fructose to 5-hydroxymethylfurfural (HMF). Under the optimal condition, an ultra-high yield of HMF was 97.4% along with 100% fructose conversion at low temperature of 50 °C when [BMIM]Cl/ethanol was used as solvent. The CDs catalyst also displayed a prominent recyclability and was used for six recycles without massive loss in catalytic activity. Furthermore, 98.6% of HMF could be obtained from final products. The findings provide a novel sustainable route using recyclable plastics to synthesize carbon dots with a superior catalytic performance for conversion of biomass to important bio-based platform chemicals. Graphic Abstract

中文翻译：

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废聚对苯二甲酸乙二醇酯衍生碳点低温分离生产5-羟甲基糠醛

摘要 以废弃的聚对苯二甲酸乙二醇酯塑料瓶为前驱体，通过空气氧化和硫酸水热处理制备碳点（CDs）。由于纳米尺寸效应和丰富的酸性基团，CDs 允许它们作为一种新型固体酸应用于果糖准均相催化脱水生成 5-羟甲基糠醛 (HMF)。在最佳条件下，以[BMIM]Cl/乙醇为溶剂，在50°C的低温下，HMF的超高产率为97.4%，果糖转化率为100%。CDs 催化剂还表现出显着的可回收性，可用于六次循环，催化活性没有大量损失。此外，98.6% 的 HMF 可以从最终产品中获得。研究结果提供了一种新的可持续途径，使用可回收塑料来合成碳点，该碳点具有卓越的催化性能，可将生物质转化为重要的生物基平台化学品。图形摘要