Abdulrahman S. Alablan

This work introduces the Reverse Steam Rising Process (RSRP), a novel dissolution method, for the preparation of highly homogeneous organo-nickel composites. This approach enables gradual material dissolution, resulting in improved material integration. We investigate two distinct synthetic pathways: a direct organic material–nickel composite and a surfactant-assisted variation. Our findings demonstrate that the inclusion of a surfactant significantly improves the properties of the resulting organo-nickel composite. The RSRP method differs from traditional synthesis methods in that it utilizes reverse steam condensation to create a highly porous, multi-level structure. This unique structure significantly boosts the material’s electrocatalytic performance, particularly for the oxygen evolution reaction (OER). The Ni-MOF-CTAB catalyst exhibits an overpotential of 397 mV at 10 mA cm⁻² and a Tafel slope of 183 mV dec⁻¹, outperforming pristine Ni-MOF. The hierarchical design promotes superior ion and gas transport, while the distinctive organometallic configuration optimizes electronic interactions critical for OER activity. This innovative process enables precise control over both the micro- and nanoscale morphology of the nickel-based catalyst, ultimately leading to superior performance metrics. This advancement offers a new pathway for developing high-performance nickel organometallic materials for diverse electrocatalytic applications.

A novel approach was used to synthesize the 5,10,15,20-tetrakis (p-thiophenol) porphyrin (TPTH-P) (2), which involved the demethylation of tetra (p-anisole) porphyrin (1) in the presence of ZnCl₂ as a catalyst and DMF as a solvent at 100 °C. The demethylation step was followed by an acidification step with concentrated H₂SO₄ to yield the desired TPTH-P (2) in an almost quantitative yield (95%). The chemical structure of the synthesized porphyrin thiol (TPTH-P) (2) was verified through spectroscopic techniques (NMR, IR, UV-Vis). The catalytic activity of TPTH-P in the hydrogen evolution reaction (HER) was investigated in 0.1 M of H₂SO₄ and 1 M of KNO₃. A self-assembled monolayer (SAM) of TPTH-P was formed on a gold electrode. The immersion time during SAM formation and the electrochemical activation cycles in H₂SO₄ were found to be important to enhancing the activity of the Au-TPTH-P electrode in the HER. Contact angle measurements and electrochemical techniques, including cyclic voltammetry (CV), linear sweep voltammetry (LSV), electrochemical impedance spectroscopy (EIS), and chronoamperometry, were used to characterize and evaluate the electrochemical activities of the SAM.

Development of efficient non-precious metals catalysts for the oxygen reduction reaction (ORR) has attracted considerable attention. A composite catalyst based on nickel- 5,10,15,20-tetra(p-thioanisole) porphyrin complex (Ni-TPT-P) and carbon fibres (CF) is here investigated for the ORR. The porphyrin is synthesised by a one-pot multi-step approach. Ultraviolet-visible (UV–vis) and fourier-transform infrared (FTIR) techniques are used to confirm the synthesis of the Ni-TPT-P complex. The metalloporphyrins (Ni-TPT-P) are non-covalently adsorbed on the CF via π − π stacking interaction. The composite catalyst shows well-defined redox peaks attributed to the Ni²⁺/Ni³⁺ redox couple in O₂-saturated 0.1 M KOH solution. The area under the reduction peak is used to calculate a surface coverage ( Г ) of 2.43 × 10¹⁵ for the Ni²⁺/Ni³⁺ species on the catalyst surface area. The rotating ring disk electrode (RRDE) technique is used to assess the performance of the catalyst towards the ORR. Key performance indicators such as the onset potential, average number of electrons and HO 2 − yield are found to be, 0.82 V vs RHE, 3.6 electrons and 22.0% respectively.