Co2 reduction toward methane

A photocathode for a photoelectrochemical cell, the photocathode comprising:

• a substrate comprising a light absorbing material, the light absorbing material being configured to generate charge carriers upon solar illumination;
• an array of conductive projections supported by the substrate, each conductive projection of the array of conductive projections being configured to extract the charge carriers from the substrate;
• a plurality of catalyst particles disposed across each conductive projection of the array of conductive projections, each catalyst particle of the plurality of catalyst particles comprising copper;
• and
• a distribution of an iron-based catalyst disposed adjacent to the plurality of catalyst particles in a co-catalyst arrangement with the plurality of catalyst particles for the reduction of carbon dioxide (CO2) in the chemical cell.