Figure 2 Block diagram of the system for temperature control
The system allows to carry out measurements at stable temperatures (±1 °C) in the range of 20–45 °C (measured at room temperatures of 25–28 °C). The circulation induced minor noise in the measurement data (approx. 1 μA), which could be eliminated by statistical methods (e.g ., a moving average).
The effect of the temperature on the reaction was investigated on the example of a sputtered WO3 photoanode (Figure 3). While the onset potential under illumination is independent of temperature in the investigated interval, the onset potential of the dark reaction decreases slightly (Table 2). The photocurrent density increases by approximately 15 %, both at 1.23 VRHE and in the plateau region. The results are close to published values.[13]