Perylenetetracarboxylic diimide modified Zn 0.7 Cd 0.3 S hybrid photocatalyst for efficient hydrogen production from water under visible light irradiation

Abstract A hybrid photocatalyst of Zn 0.7 Cd 0.3 S and perylenetetracarboxylic diimide (PDI) was prepared with a facile co-precipitation-hydrothermal method. The structure and morphology of Zn 0.7 Cd 0.3 S/PDI photocatalyst was investigated systematically by X-ray diffraction experiments (XRD), atomic force microscopy (AFM), transmission electron microscopy (TEM), and scan electron microscopy (SEM), etc. The H 2 production rate of Zn 0.7 Cd 0.3 S/PDI is 5.166 mmol h −1  g −1 in the aqueous solution of sacrificial reagents Na 2 SO 3 and Na 2 S, which is 6.5 times of that of pure Zn 0.7 Cd 0.3 S solid solution without PDI modification. The corresponding apparent quantum efficiency (QE) of Zn 0.7 Cd 0.3 S/PDI nanocomposite is 22.5% under monochromatic light irradiation at 420 nm, which is also significantly higher than that of pure Zn 0.7 Cd 0.3 S solid solution (3.35%). Comparing to Zn 0.7 Cd 0.3 S solid solution, higher transient photocurrent is measured for the Zn 0.7 Cd 0.3 S/PDI nanocomposite. This result indicates that PDI can collect the photogenerated electrons in Zn 0.7 Cd 0.3 S, thereby inhibiting the photogenerated electron-hole pair recombination of Zn 0.7 Cd 0.3 S/PDI nanocomposite. This Zn 0.7 Cd 0.3 S/PDI hybrid catalyst suggests that organic semiconductor modification is a useful way for enhancing the photocatalytic performance of Zn x Cd 1−x S.