Interestingly, a clear difference in the electrolyte media characteristics around the cathode and the anode is observed with the bright and dark fluorescent phases merging at the centre point between the electrodes. These dark/bright phases are due to the formation of protonated and deprotonated forms of HPTS at the anode and cathode, respectively (Figure ,f). To understand the effect of decrease in the distance between the electrodes, the fluorescence images were ratiometrically analysed in-depth in order to see the comparative pH changes occurring at the electrodes at far and close inter-electrodes distances (Figure The detrimental effect of pH changes at the electrodes during water splitting under neutral conditions can also be minimized by replacing the water "shell" around the electrodes continuously. One plausible practical approach to do so is by flowing electrolyte in a flow-type electrolysis cell, which can provide in-situ 'buffering' conditions. The in-situ spatiotemporal imaging technique developed in this study was explored to visualize the water splitting reactions under flow conditions. For this purpose, the opto-electrochemical cell developed in this work was equipped with flowing electrolyte capabilities, through the use of an external automated syringe pump (Figure ). To analyse the effect of different flow conditions on the electrochemical water splitting process, the change in the measured electrolyser's current under different electrolyte flow rates was investigated under static and flow conditions (Figure ).