**1. Introduction**

Life is dependent on photosynthesis, directly or indirectly. Photosynthesis is converting sunlight, water, and carbon dioxide into carbohydrates and oxygen (Govindjee et al., 2010). Artificial photosynthesis is a research field that attempts to replicate the natural process of photosynthesis. The goal of artificial photosynthesis is to use the energy of the sun to make different useful material or high - energy chemicals for energy production. In this regard, a good question is that why artificial photosynthesis is important and necessary?

There are some reasons for believing that artificial photosynthesis is necessary in future. Two reasons are very important: the first, oil will become scarcer and more expensive and we should find a better source of energy. The second is causing serious environmental problems by fossil fuels.

Artificial photosynthesis could be divided into a series of approaches:
