Results and discussion
The PEC measurement system (Figure 1) has been designed to work with a standard vertical solar simulator. It offers room for PEC cells with absorber sizes of up to 16x16 cm2, as well as for the required equipment (e.g., for temperature control),
The system is built from a metal frame and six cardboard plates and houses a solar-grade mirror and a sliding holder for the electrochemical cell. The frame is made from commercial aluminum profiles and has feet which are separately height-adjustable to allow installation on tables or over edges. Five fixed and one removable cardboard plates are attached to the frame. Black surfaces on the inside prevent light reflection, which could otherwise result in an increased irradiation on the photoelectrode. With a closed front side, the setup protects the experimenter from irradiation. The light of a vertical solar simulator enters the setup from above and is reflected by a tiltable solar-grade mirror on the PEC cell. A sliding cell holder supports the positioning of the cell with a high degree of reproducibility. It fixates the cell on the platform and minimizes the danger of spilling chemicals. The holder can be removed if large cells are investigated. The system can be equipped with different PEC reactor types, a potentiostat and auxiliar equipment for monitoring, imaging, or spectroscopic applications.
Table 1 Geometrical data of the PEC measurement system with data for spatial non-uniformity according to IEC 60904-9