KCS

Copper indium disulfide (CuInS2, CIS) is suitable for cathode cause it is a p-type semiconductor as visible light driven catalyst (band gap ~1.5 eV) and it has a high absorption coefficients ( >105 cm-1) and appropriate band position for CO2 reduction to methanol. In general CIS electrode can be fabricated by electrochemical deposition followed by sulfurization but in our case CIS thin film was fabricated by simple annealing process using precursors dissolved in pyridine. Instead of water based solvent system, pyridine has a strong coordinating with solvent which can help the decomposition of the precursors catalytically. And also we incorporate reduced graphene oxide (r-GO) with CIS film. r-GO will be helpful to enhance photocurrent and also by varying the reduction level of graphene oxide we can control the reduction potential level for effective methanol production( ~0.38 eV). r-GO-CIS film can be made simply by just mixing graphene oxide with precursors. This r-GO-CIS film can be applied well as cathode for methanol production which is our final purpose in artificial photosynthesis