Plants do not need pure hydrogen to survive, but they do need hydrogen and oxygen molecules together in the form of water, which is a vital ingredient in the process of photosynthesis. This process uses water, carbon dioxide and energy from sunlight to create chemical energy.
When carbon dioxide and water are energized by the sun, a chemical process takes place that produces glucose, water and oxygen. The glucose is used by the plant for energy to survive. Water is typically absorbed by plants through roots in the ground and transported to the leaves through vascular systems. Carbon dioxide is absorbed through pores in leaves called stoma, and sunlight is absorbed through chlorophyll in plant cells, thus completing the photosynthesis equation.