Enhanced H₂O₂ Upcycling into Hydroxyl Radicals with GO/Ni:FeOOH-Coated Silicon Nanowire Photocatalysts for Wastewater Treatment

There remains continued interest in improving the advancedwateroxidation process [e.g., ultraviolet (UV)/hydrogen peroxide (H2O2)] for more efficient and environmentally friendlywastewater treatment. Here, we report the design, fabrication, andperformance of graphene oxide (GO, on top)/nickel-doped iron oxyhydroxide(Ni:FeOOH, shell)/silicon nanowires (SiNWs, core) as a new multifunctionalphotocatalyst for the degradation of common pollutants like polystyreneand methylene blue through enhancing the hydroxyl radical (& BULL;OH)production rate of the UV/H2O2 system. The photocatalystcombines the advantages of a large surface area and light absorptioncharacteristics of SiNWs with heterogeneous photo-Fenton active Ni:FeOOHand photocatalytically active/charge separator GO. In addition, thebuilt-in electric field of GO/Ni:FeOOH/SiNWs facilitates the chargeseparation of electrons to GO and holes to Ni:FeOOH, thus boostingthe photocatalytic performance. Our photocatalyst increases the & BULL;OHyield by 5.7 times compared with that of a blank H2O2 solution sample and also extends the light absorption spectrumto include visible light irradiation.