Supporting Information for:
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Role of Sulfites in the Water Splitting Reaction
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Chunxiang Li · Pingan Hu · Hui Meng · Zhaohua Jiang
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An annular quartz photoreactor (diameter: 30 cm, height: 70 cm) placed in the vertical
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position was illuminated by inside fixed lamps (30 W × 13, λem = 254 nm). The total
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volume of solution used was 45 L (0.1 mol·L–1 Na2S + 0.01 mol·L–1 Na2SO3). Prior to
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irradiation, the sacrificial agent solution was purged with high purity nitrogen for 30
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min. The amount of gas generated was measured by a flowmeter at room temperature
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(25 °C) and at normal pressure. At fixed time intervals, 5 mL of evolved gas was
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collected and analyzed by a gas chromatograph (GC, HP 5890 II) equipped with TCD
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(Molecular Sieve 5-A, Ar carrier). The amount of hydrogen generated from the
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photoreactor was calculated based on the flowmeter and gas chromatography results.
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After each 8 hour run, solid Na2SO3 was added to the reacting solutions.
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Table 1 Amounts of hydrogen production versus reaction time
Reaction time (h)
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24
32
40
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H2 volume (L)
43.53
87.03
130.49
173.94
217.35
260.73
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Fig. S1 ESR spectra of the ·OH-radical for 0.1 mol·L–1 Na2S + 0.0 mol·L–1 Na2SO3
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solution with 30 µL of 2.5 mol·L–1 DMPO added into 10 mL of the Na2S–Na2SO3
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sacrificial agent
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Fig. S2 Amount of hydrogen production versus reaction time from 50 mL of 0.1
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mol·L–1 Na2S and 50 mL of 0.01 mol·L–1 Na2SO3 solutions under UV irradiation
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