Plasma-activated polypropylene coated with alginate-phosphorous triazatetrabenzocorrole for diesel photodegradation

[Display omitted] •The photocatalytic polypropylene was prepared by plasma-etching and catalyst-coating.•The prepared polypropylene can degrade spilled diesel in seawater.•The degradation of diesel was independent with pH and H2O2.•The photocatalyst in prepared polypropylene was metal-free and degradable. The leakage of heavy metals, dependence on H2O2, and difficulty of loading restrict the application of nano-oxide photocatalyst in the treatment of marine petroleum pollution. In this study, a photocatalytic absorbent pad was prepared on a plasma-activated polypropylene substrate using phosphorous triazatetrabenzocorrole as the photocatalyst and sodium alginate as the catalyst carrier. In seawater, sodium alginate can form a gel layer (calcium or magnesium alginate) on the polypropylene pad surface to achieve efficient photocatalysis. The prepared photocatalytic pad can overcome the physical adsorption limit of commercial polypropylene and continuously degrade diesel in seawater under visible-light irradiation. Moreover, the prepared polypropylene pad did not contain heavy metals and showed an advantage of pH independence.