One-step synthesis CdS/single crystal ZnO nanorod heterostructures with high photocatalytic H2 production ability

Abstract

CdS/single crystal ZnO nanorod heterostructure (CdS/ZnO) was fabricated via microwave synthesis method, and the structural, morphological and photocatalytic hydrogen generation was tested. Studied results demonstrated that CdS particles were decorated on the surface of single crystal ZnO nanorod with crystallite size about 43 nm, and CdS nanoparticle significantly enhanced the photocatalytic hydrogen generation ability of the heterostructure by increasing the specific surface area, promoting the separation, migration of photoinduced carriers and increasing the light absorption. Pure ZnO exhibits bandgap energy of 3.09 eV, while the CdS/ZnO sample possessed a more narrow band gap (2.62 eV) than ZnO nanorod. Under the irradiation of visible light, the highest photocatalytic hydrogen production rate of 4076 µmolg−1h−1 is observed over the CdS/ZnO with the content of CdS is 38 wt%, which is about 13.59 and 76.91 times more active than pure ZnO nanorod and CdS nanoparticle. In addition, the specific surface area of the composite sample reaches 43.375 m2/g, and the instantaneous photocurrent reaches 130 μA /cm2. The present microwave radiation method is simple, easy to control, and timesaving, thereby providing a efficient route for the preparation of metal oxide-based photocatalytic material with high hydrogen evolution activity.