Browsing by Author "Olusola O. James"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Theoretical studies of the suitability of imidazolypyridine as bidentate ligands for copper redox couples in the Dye Sensitized Solar Cell (DSSC) application
    (Research Square, 2025-12-19) Wahab Osunniran; Abdullateef Salaudeen; Bolatito E. Olanipekun; Sunday W. Balogun; Sikiru Ahmed; Olusola O. James
    Copper complex redox couples have emerged as alternative redox mediator to iodide/triiodide redox couple for DSSC devices. The copper redox couples enable high and tunable voltage in DSSC devices. However, the Cu(II) species in a typical copper redox couples are strongly electrophilic towards injected electrons in TiO2 thereby promoting recombination and decreases the cell performance. Although 4-tertbutylpyridine (TBP) passivation of TiO2 surface reduces the extent of the recombination, its interaction with Cu(I) complex in a copper redox couples may be detrimental to the cell performance. Therefore, rational selection of ligands of the copper complexes is critical in obtaining high voltage and performance. In this work, Density Functional Theory (DFT) was adopted to screen four imidazoly-pyridine bidentate ligands: 2-(1-methyl-4,5- dihydro-1H-imidazol-2-yl)pyridine (MDIP); 2-(1-methyl-1H-imidazol-2-yl)pyridine (MIP); 2- (1,4,5-trimethyl-1H-imidazol-2-yl)pyridine (TMIP) and 1-methyl-2-(pyridin-2-yl)-1Hbenzo[ d]imidazole (MPBI). Calculated binding constants of interaction of 4-tertbutylpyridine (TBP) with the imidazoly-pyridine copper complexes indicated Cu(I) complexes of MDIP and MIP interact strongly with TBP. This has adverse effects on device voltage, thus, making MDIP and MIP ligand unsuitable. But Cu(I) complexes of TMIP and MPBI interact very weakly with TBP, indicating they are suitable ligands for copper complex redox couples for DSSC application
  • Thumbnail Image
    Item
    Towards selective electrochemical conversion of glycerol to 1,3-propanediol
    (2018) Olusola O. James; Waldemar Sauter; Uwe Schroder
    1,3-propanediol (1,3-PD) is a bulk chemical with myriad applications in polymers, lubricants, cosmetics, foods industries and in the synthesis of heterocyclic compounds. Current commercial production of 1,3-PD involves a thermocatalytic process using acrolein (DuPont) and ethylene oxide (Shell) as starting feedstock. These feedstocks are petroleum-based and there are many efforts at using glycerol as low cost biomass-derived feedstock for 1,3-PD production. A number of catalyst designs and bacterial & fungal strains are being explored for respective catalytic and fermentation routes to glycerol-to-1,3-PD. However, the electrochemical method received little attention for the purpose. In this work, in order to explore the possibility of using partly refined glycerol byproduct of biodiesel production as feedstock, we investigated conversion and 1,3-PD selectivity of glycerol electrolysis in chloride media. We demonstrated selective glycerol-to-1,3-PD conversion using Pt or RuO2-based dsa as anode and Zn or Pb as cathode in NaCl and KCl at pH 1. This electrochemical glycerol-to-1,3-PD conversion is not only green, it is a potential process network loop between biodiesel production and chlor-alkali industry.