Synthesizing vertical porous ZnO nanowires arrays on Si/ITO substrate for enhanced photocatalysis

Abstract In this work, porous ZnO nanowires arrays (NWAs) which are perpendicular to the substrate were synthesized using facile and simple hydrothermal process approaches. The surface of ZnO nanowires (NWs) was increased by chemical electroless etching many macropores on them, which results in better photocatalytic activity, which is 1.73 times in terms of the rate constant for methyl orange (MO) degradation for porous ZnO NWAs compared with ZnO NWAs. The absorption of the vertical porous ZnO NWAs was considerably enhanced in the visible region. The optical band-gap became slightly narrower from 3.24 eV (ZnO NWAs) to 3.22 eV (porous ZnO NWAs). Thus, the vertical porous ZnO NWAs can be employed for various applications, such as gas sensor, photocatalyst, and solar cell.