Effect of donor-donor-π-acceptor architecture of triphenylamine-based organic sensitizers over TiO2 photocatalysts for visible-light-driven hydrogen production

摘要: In this paper, we report a series of triphenylamine (TPA) donor based dyes in sensitized hydrogen production over TiO2–Pt catalysts under visible light. Among the selected dyes, 4-(diphenylamino) phenylcyanoacrylic acid (DN-F01), 5-[4-(diphenylamino)phenyl]thiophene-2-cyanoacrylic (DN-F02), 3-(5-(4-(diphenylamino)styryl) thiophen-2-yl)-2-cyanoacrylic (DN-F03), (E)-3-(5-(4-(bis(2′,4′-dibutoxy-[1,1′-biphenyl]-4-yl)amino)phenyl) (DN-F04) and 3-(6-(4-(bis(2′,4′-dibutoxy-[1,1′-biphenyl]-4-yl)amino)phenyl)-4,4-dihexyl-4H-cyclopenta[1,2-b:5,4-b′] dithiophen-2-yl)-2-cyanoacrylic (DN-F05) were adsorbed on Pt–TiO2 tested for photocatalytic visible-light presence triethanolamine (TEOA) as sacrificial electron (SED). The enhanced light absorption effective interfacial charge transfer from excited dye to TiO2 is significant DN-F05-TiO2. DN-F05 (DN5@T) photocatalyst exhibited higher turnover number (TON 1864) apparent quantum efficiency (AQE ∼44%) when compared their corresponding simple architecture molecules. Moreover, additional donating group di-butoxyphenyl dihexyl-cyclopentyl π-conjugated bridge units provide an excellent surface protection through steric hindrance leading good performance. Electrochemical computational studies suggest better activity DN5@T. shows long term stability reproducibility at neutral pH.