Photoelectrocatalytic reduction of carbon dioxide to methanol at cuprous oxide foam cathode

In order to increase the reduction rate of CO2 to methanol, the photoelectrocatalytic reduction of CO2 at Cu2O foam electrodes is proposed. The Cu2O foam electrodes are fabricated by electrodeposition of Cu2O coatings on copper foam substrates. The effect of bath pH and deposition time on the morphology and structure is investigated. The Cu2O foam electrodes deposited at bath pH 10 for 20 min exhibit higher intensity of ( 111) diffraction peak. The photoelectrocatalytic performance of Cu2O foam electrodes for CO2 reduction to methanol depends largely on exposed Cu2O{111} facets. At the applied potential of -1.5 V ( vs. saturated calomel electrode), the optimum methanol concentration and the faradaic efficiency of methanol formation are obtained within 1.5 h, and they are 1.41 mM and 29.1%, respectively. The formation rate of methanol achieves 23.5 mu mol cm(-2) h(-1) within 1.5 h.