Gumrukcu, SelinKaplan, EkremKarazehir, TolgaOzcesmeci, MukaddesOzcesmeci, IbrahimHamuryudan, Esin2025-01-062025-01-0620240360-31991879-348710.1016/j.ijhydene.2024.09.2842-s2.0-85204936691https://doi.org/10.1016/j.ijhydene.2024.09.284https://hdl.handle.net/20.500.14669/2585Creating innovative catalysts utilizing nonprecious metals for the electrocatalytic hydrogen evolution reaction (HER) poses a significant difficulty. We present a cobaloxime (Cox) complex having pyridine (2-Cox) and tetrafluorophenyl-thio-pyridine (4-Cox) functional groups, which contains a 4,4-Difluoro-4-bora-3a,4a-diaza-s-indacene (BODIPY) moiety. This combination serves as a catalyst for proton reduction and is immobilized onto reduced graphene oxide (rGO) by pi-pi stacking between the cobaloxime complex and rGO. Moreover, the unique complex's structures were determined through the application of ultraviolet-visible spectroscopy (UV-Vis), Fourier Transform Infrared spectroscopy (FT-IR), X-ray diffraction spectroscopy (XRD), and scanning electron microscopy (SEM). The electrocatalytic activity of the two rGO/2-Cox and rGO/4-Cox electrodes towards hydrogen (H-2) were examined under both alkaline and acidic conditions. The cobaloxime-modified rGO electrodes demonstrate superior electrocatalytic performance for the HER under acidic conditions compared to alkaline conditions. The overpotential at a current density of 10 mA cm(-2) for rGO/2-Cox in 0.5 M H2SO4 is -0.342 V, which is notably lower than the overpotential of rGO/4-Cox (-0.496 V). The Tafel slope for the rGO/2-Cox electrode in a 0.5 M H2SO4 solution is 111 mV.dec(-1), but for the rGO/4-Cox electrode it is 156 mVdec(-1). This discrepancy suggests that the rGO/2-Cox electrode demonstrates better performance in the HER compared to the rGO/4-Cox electrode.eninfo:eu-repo/semantics/closedAccessHydrogen evolution reaction (HER)BODIPYCobaloximeAcidic water electrolysisAlkaline water electrolysisArticle473Q146289WOS:001329098400001N/A