Enhanced Photocatalytic Activity of WS Film by Laser Drilling to Produce Porous WS/WO Heterostructure.

Methods and mechanisms for improvement of photocatalytic activity, are important and popular research topics for renewable energy production and waste water treatment. Here, we demonstrate a facile laser drilling method for engineering well-aligned pore arrays on magnetron-sputtered WS nanofilms with increased active edge sites; the proposed method promotes partial oxidation to fabricate WS/WO heterojunctions that enhance the separation of photogenerated electron-hole pairs. The WS film after one, two, and three treatments exhibited photocurrent density of 3.9, 6.2, and 8 μA/cm, respectively, reaching up to 31 times larger than that of pristine WS film along with greatly improved charge recombination kinetics. The unprecedented combinational roles of laser drilling revealed in this study in regards to geometric tailoring, chemical transformation, and heterojunction positioning for WSbased composite nanomaterials create a foundation for further enhancing the performance of other 2D transition metal dichalcogenides in photocatalysis via laser treatment.