Mesoporous carbon nitrides are highly valuable materials with various properties, including basicity, semiconductivity, high rigidity and chemical stability, with an enlarged overall surface area from the mesoporous structure. They have great potential applications in water splitting, metal free catalysis, gas adsorption, energy storage and conservation due to the mesoporous structure. A well-ordered mesoporous carbon nitride is expected to have superior photocatalytic activity in the degradation of rhodamine b. However, the widely used templating synthesis of mesoporous carbon nitrides involves removal of the expensive silica template using the extremely toxic hydrogen fluoride, which makes it unsustainable. A novel salt template will be investigated in this thesis to synthesise mesoporous carbon nitride. Because of the solubility of salt in water, the new synthesis method will not require the dangerous hydrogen fluoride to remove the template. The stability and recyclability of the salt template can dramatically decrease the cost of synthesised mesoporous carbon nitride. The resulting materials were characterised using X-ray diffraction (XRD, Brunauer-Emmett-Teller method (BET), Fourier transform infrared spectroscopy (FTIR spectroscopy) and thermogravimetric analysis (TGA). The degradation of rhodamine b was employed to test the photocatalytic activity of the prepared material.