Sensitizers D-A1-A2-π-A Include 10'H-Spiro[fluorene-9,9’-Phenanthren].Benzo[c] and -10‘-one.[ 1, 2, 5]Thiadiazole for Photocatalytic Hydrogen Production and Dye-Sensitized Solar Cells

The structural modifications prevent molecular aggregation by adding a bulky spiro[fluorene-9,9’-phenanthrene ]-10’ auxiliary acceptor (A
1
) and benzo[c][1,2,5]thiadiazole (A
²
) between the donor and π-bridge moiety. Additionally, the carbonyl group improves the capture of Li
⁺
ions, delaying charge recombination. Moreover, sensitizer FZ-2's light absorption range is expanded and its energy conversion efficiency is improved under AM1.5 circumstances, reaching up to 5.72%, thanks to the enlarged π-conjugation. Co-sensitization testing under one sun revealed an effectiveness of 9.60% using N719 and FZ-2. Due to FZ-2's strong absorption efficiency at short wavelengths, which offsets N719's inadequacies in this range, the co-sensitization performance of FZ-2 and N719 is superior. Additionally, FZ-sensitizers demonstrate excellent photocatalytic hydrogen production efficiency. The hydrogen production activities of FZ-1 are 7430 µmol/g (1 hour) and 64004 µmol/g (12 hours), FZ-2 hydrogen production activities are 9190 µmol/g (1 hour) and 76582 µmol/g (12 hours). This suggests that FZ-2 is more effective at injecting charges into TiO
2
and using them for water splitting. After 12 hours of photocatalytic water splitting stability tests, FZ-1 and FZ-2 exhibited TON of 4249 and 5378, respectively.