Figure 5.

(a) Spectrophotometry of the appearance (during irradiation) and disappearance (upon addition of NiP in the dark) of photoexcited electrons in ^NCNCN_x at λ = 650 nm. A suspension with ^NCNCN_x (5 mg) and 4-MBA (30 μmol) in KP_i (0.02 M, pH 4.5, 3 mL) was irradiated (AM 1.5G) for 30 min, followed by addition of NiP (50 nmol, 400 μL) or KP_i (400 μL). (b) Two photoreactors were prepared with ^NCNCN_x (5 mg) and 4-MBA (30 μmol) in the absence of NiP in an aqueous KP_i solution (0.02 M, pH 4.5, 3 mL) and irradiated with 1 sun irradiation (AM 1.5G, 25 °C). Both of these photoreactors were taken into the dark after 4 h of irradiation, while NiP (50 nmol) was added to one of them. The pair of hollow and filled symbols of the same shape and color corresponds to H₂ and aldehyde production, respectively, under the specified reaction conditions.