Photosynthesis is the natural process that converts CO using light to produce hydrocarbon compounds such as sugar. The depletion of fossil fuels encourages scientists to find alternatives to produce hydrocarbon compounds. Artificial photosynthesis is a promising method  mimicking the natural photosynthesis to produce such compounds. The photoelectrochemical reduction of  is much studied because of its worldwide impact. Many researchers aim to find new semiconductors to develop stable and efficient photo-anodes and photo-cathodes.