Table 2. Results of visible light driven H2 evolution with CoPn and RuP in solution or in particle suspensions with TiO2 or ZrO2 a .
| TOFCo b (1 h)/h–1 | TONCo c (4 h) | n c (H2)/μmol (4 h) | |
| pH 7 (TEOA) | |||
| RuP|CoP3 | — | — | <0.03 d |
| RuP|ZrO2|CoP3 | — | — | <0.03 d |
| RuP|TiO2|CoP3 | 10.3 ± 0.4 | 12.3 ± 0.3 | 1.23 ± 0.03 |
| RuP|TiO2|CoP3centr. e | n.d. f | n.d. f | 0.74 ± 0.27 |
| RuP|TiO2|CoP2 | 0.6 ± 0.1 | 2.4 ± 0.1 | 0.24 ± 0.01 |
| RuP|TiO2|CoP1 | 44.0 ± 0.9 | 56.6 ± 2.2 | 5.66 ± 0.22 |
| RuP|TiO2, no CoP3 | n.d. f | n.d. f | 0.14 ± 0.07 |
| pH 4.5 (AA) | |||
| RuP|CoP3 | 2.1 ± 0.6 | 3.1 ± 0.4 | 0.31 ± 0.04 |
| RuP|ZrO2|CoP3 | 8.1 ± 2.2 g | 9.9 ± 0.2 | 0.99 ± 0.02 |
| RuP|TiO2|CoP3 | 12.8 ± 0.6 g | 18.4 ± 0.5 | 1.84 ± 0.05 |
| RuP|TiO2|CoP2 | 1.2 ± 0.2 | 1.2 ± 0.1 | 0.12 ± 0.01 |
| RuP|TiO2|CoP1 | — | — | <0.03 d |
| RuP|TiO2, no CoP3 | — | — | <0.03 d |
| RuP|ZrO2, no CoP3 | n.d. f | n.d. f | 0.09 ± 0.02 |
| RuP, no CoP3 | — | — | <0.03 d |
aThe following standard conditions were employed unless otherwise noted: AM 1.5G, 100 mW cm–2, λ > 420 nm irradiation, 0.1 μmol of CoPn and 0.1 μmol of RuP in homogenous solution or in suspensions with TiO2 or ZrO2 nanoparticles (5 mg) in aqueous TEOA or AA solution (2.25 mL, 0.1 M). Mean values ± standard deviation (σ) given from at least three different reaction vessels.
bTOF based on CoPn for the first hour of irradiation.
cTON based on CoPn and total of headspace H2 accumulated after four hours irradiation.
dBelow the limit of detection by gas chromatography.
eParticles were loaded with the catalyst and the dye, centrifuged and re-suspended in fresh buffer solution prior to use.
f n.d. = not defined (no CoP3 present or amount of CoP3 not precisely known).
gTOF is based on the maximum H2 evolution rate after the initial lag period.