Pure organic quinacridone dyes as dual sensitizers in tandem photoelectrochemical cells for unassisted total water splitting.

Pure organic dye QAP-C8 based on quinacridone (QA) with octyl side chains as the donor and pyridine dicarboxylic acid (PDA) as the acceptor was first used in both the photoanode and the photocathode of photoelectrochemical cells. A tandem device with QAP-C8 as the photosensitizer realized overall water splitting and showed a STH of 0.11% under neutral pH conditions without an external bias.

Enhanced Photocurrent via π-Bridge Extension of Perylenemonoimide-Based Dyes for p-Type Dye-Sensitized Solar Cells and Photoelectrochemical Cells.

Two dyes TB and TSB containing triphenylamine as the donor and perylenemonoimide as the acceptor, with and without bithiophene as π-bridge, respectively, were successfully prepared and characterized for p-type dye-sensitized solar cells (p-DSSCs) and dye-sensitized photoelectrochemical cells (DS-PECs). As a result, TSB with bithiophene π-bridge exhibited a broader absorption spectrum and a higher molar extinction coefficient than TB. Furthermore, the photocurrents of p-DSSCs and DS-PECs for the dye TSB were increased by 26.9 and 32.9%, respectively, compared with those of the dye TB. Meanwhile, the electrochemical impedance spectroscopy of the TSB-based p-DSSC showed the smaller charge-transfer resistance and larger hole lifetime because the longer π-bridge facilitated charge transfer and separation within the dye molecule and effectively prevented the hole recombination process at the NiO/dye interface, resulting in improvement of photoelectric performance. Hence, these results show that the π-bridge extension of dyes has a promising effect on the photocurrent improvement of p-DSSCs and DS-PECs.