Photoelectrochemical reduction of carbon dioxide at CuInS2/graphene hybrid thin film electrode

Converting CO2 to methanol, a solar fuel, will not only reduce CO2 emission, but also alleviate energy shortage. In this study, a photoelectrochemical reduction reaction of CO2 to methanol is conducted using CuInS2/graphene hybrid thin film as the photocathode. CuInS2 and CuInS2/graphene hybrid thin films are fabricated at 30 °C in dimethyl sulfoxide by one-step electrodeposition. The photocurrent densities of CuInS2/graphene hybrid thin films are almost twice those of CuInS2 thin films. Furthermore, the resulted CuInS2/graphene hybrid thin film electrode exhibits better catalytic performance for photoelectrochemical reduction of CO2 to methanol than the CuInS2 thin film electrode. At the applied potential of −0.59 V, pyridine concentration of 10 mM, and pH of 5.2, higher methanol yield can be obtained at CuInS2/graphene hybrid thin film electrode; and the rate of methanol formation at CuInS2/graphene hybrid thin film electrode is about 1.4 times that at CuInS2 thin film electrode.