Near-infrared-dominated photothermal nanofluids for degradation and H2-producing photochemical reforming of fiber-based microplastics

One effective strategy to solve the existing limits of photocatalyst applications is to broaden the spectrum absorption range of catalysts for the degradation and conversion of microplastics. As a result, a brand-new composite system BN/PDA/MoS2 (BPM) was developed in this work to form nanofluids for the degradation and reformation of fiber-based microplastics (FMPs) under the irradiation of near-infrared light (NIR) for the first time. The collaborative system BPM nanofluids/NIR could remove 94.7% and 95.2% of reactive blue KN-R (100 mg/L) and Cr (VI) (10 mg/L) within 60 min, along with the temperature of the system could reach 58°C within 30 min. The weight loss rates of FMPs like PET and PLA were 92% and 34%, respectively after undergoing molecular chain breakage to form a series of small molecules in the system. Moreover, the H2 production maintained an improvement to 100 mmol g−1 (PET) as well as 160 mmol g−1 (PLA) compared to the past research. In conclusion, this work is an effective attempt to develop a new method for water treatment based on the photothermal degradation of microplastics by BPM nanofluids, which also bears new ideas and ways for industrial pollutant removal and waste utilization.