• Energy Research

Abstract A new photosensitizer, PCA-ZnPc-2, was synthesized through the asymmetric functionalization of phthalocyanine ring with a pyrazole-3-carboxylic acid as the electron-withdrawing and anchoring group and six hexylsulfanyl as the bulky electron-donating groups. PCA-ZnPc-2 was tested in dye-sensitized solar cells (DSSCs) and its performance was compared with PCA-ZnPc-1. It was found that PCA-ZnPc-2 has higher electron-donating ability which is favorable for light harvesting and suppress the dye aggregation on TiO2 when compared to PCA-ZnPc-1. Also, the new photosensitizer was used in dye-sensitized photoelectrochemical cells for hydrogen production under visible irradiation. The results show that PCA-ZnPc-2 is a promising photosensitizer to harvest the red/near-IR regions.

Abstract In this study, photoelectrochemical performance of reduced graphene oxide (RGO)-CdxZn1-xS composites, which were synthesized through a novel two-steps thermal sulfurization process by using elemental sulfur, was reported. This is the first time that the two-step thermal sulfurization process with elemental sulfur for the preparation of photoanode based on RGO-CdxZn1-xS. The electrodes exhibited high photostability and photocurrent response in the presence of visible light. The presence of RGO in CdxZn1-xS as electron collector and transporter increased the photocurrents approximately 40%. Among the RGO-CdxZn1-xS composites, RGO-CdS photoanode yielded an extremely high photocurrent density of 6.5 mAcm−2 with the rate of hydrogen production rate of 551.1 μ m o l h − 1 c m − 2 . This value of photocurrent density is almost 89% of its theoretical value. This is the maximum attained photocurrent density with superior stability in comparison with related literature.