One of the fundamental needs is energy for life and various studies were carried out in search of green, sustainable, and renewable energy sources. Photocatalytic hydrogen evolution is a promising route for the conversion of solar energy to hydrogen energy and in this process, energy production and wastewater treatment could be achieved as concomitant. To achieve higher hydrogen evolution rates, various photocatalysts have been developed and graphitic carbon nitride-based (CN) photocatalysts are promising ones. In this chapter, the photocatalytic properties of pristine CN and element-doped CN and the effect of these properties on the evolution rates were briefly discussed and some related studies from the literature were summarized.