Liu RKUAN-CHEN CHENG et al.2021-07-262021-07-26202115726657https://www.scopus.com/inward/record.uri?eid=2-s2.0-85103622426&doi=10.1016%2fj.jelechem.2021.115167&partnerID=40&md5=ad22e4c7463abdce070462d2a02f8fd0https://scholars.lib.ntu.edu.tw/handle/123456789/572941Carbon-based conductive materials have been recognized as promising alternatives to noble metals as the electrode in optoelectronic devices. Herein, by utilizing energetic plasma ion implantation, Ni-doped TiN nanowire (NWs) modified graphitic carbon nanofibers (CNF) are designed and prepared as the candidates of the platinum (Pt) counter electrode for low-cost hybrid perovskite-based liquid-junction photoelectrochemical solar cells (LPSCs). Notably, the photoelectrochemical (PEC) response of p-Rb0.05FA0.95PbI3 based-LPSCs equipped with the Ni/TiN/CNF counter electrode is almost identical to that with a typical Pt counter electrode. From electrochemical investigations, i.e., electrochemical impedance spectroscopy (EIS), we observe that the CNF-based materials show a similar redox activity compared with the Pt counter electrode, indicating low charge-transfer resistance (Rct) and large capacitance (C). The LPSCs, with a configuration of p-Rb0.05FA0.95PbI3/BQ (2 mM), BQ[rad]? (2 mM)/Ni/TiN/CNF-based counter electrode, exhibit an open-circuit photovoltage of 1.00 V and a short-circuit current density of 7.02 mA/cm2 under 100 mW/cm2 irradiation. The overall optical-to-electrical energy conversion efficiency is 5.06%. The PEC solar cell shows good stability for 5 h under irradiation. The CNF-based counter electrode enables potential applications, including but not limited to PEC solar devices, dye-sensitized solar cells (DSSCs), solar fuel devices and hydrogen evolution reaction. ? 2021 Elsevier B.V.Carbon nanofibers; Charge transfer; Cost effectiveness; Dye-sensitized solar cells; Electrochemical electrodes; Electrochemical impedance spectroscopy; Irradiation; Nickel compounds; Perovskite; Perovskite solar cells; Redox reactions; Solar power generation; Carbon material; Carbon nanofibres; Carbon-based; Cost effective; Counter electrodes; Liquid junctions; Optoelectronics devices; Photo-electrochemistry; Photoelectrochemical solar cell; Platinum counter electrodes; Platinum[SDGs]SDG7journal article10.1016/j.jelechem.2021.1151672-s2.0-85103622426