Photocatalytic degradation of organophosphorus pesticides coupled with hydrogen production using titanium dioxide modified with both fluoride and platinum

This study investigates the degradation of organophosphorus pesticides coupled with hydrogen (H2) production using titanium dioxide modified with fluoride and platinum (F−/TiO2@Pt). In the presence of dicrotophos (300 μM) under anoxic conditions, F−/TiO2@Pt achieved complete degradation and produced 17.87 μmol of H2 after 4 h. In contrast, only 42.4 μM, 92.4 μM, and 251.5 μM of dicrotophos were degraded using bare TiO2, F−/TiO2, and TiO2@Pt, respectively, with significantly lower or negligible H2 production (i.e., 6.60 μmol with TiO2@Pt and negligible amounts with bare TiO2 and F−/TiO2). The markedly enhanced degradation of dicrotophos and H2 generation by the dual surface modification with F− and Pt, compared to single-component modifications, is attributed to the synergistic action of F− and Pt in suppressing charge recombination and promoting electron transfer to H+. Beyond dicrotophos, F−/TiO2@Pt also exhibited superior degradation efficiency and H2 production compared to TiO2@Pt in the presence of various organophosphorus pesticides, including dichlorvos, trichlorfon, acephate, ethoprophos, methacrifos, and fenamiphos. Furthermore, F−/TiO2@Pt outperformed TiO2@Pt under all tested experimental conditions, including variations in F− concentration, catalyst dosage, Pt loading, and pH, except at pH 11.0. This study demonstrates an effective surface modification strategy for dual-function photocatalysis targeting organophosphorus pesticide degradation and H2 production.