Molten-salt synthesis of Fe-doped carbon nitride nanosheets for photocatalytic seawater splitting and glucosamine hydrochloride oxidation

Herein, carbon nitride (MCN) samples were first prepared by the molten salt method, and then Fe-doped carbon nitride (MCN) was prepared by a two-step method of calcination and hydrothermal heating and used as a novel photocatalyst for the photodegradation of seawater for the generation of H2 or O2 and as a sacrificial agent when glucosamine hydrochloride is present. As a result, Fe species existed in the form of Fe3+/Fe2+ in the carbon nitride flakes, which reduced the bandgap width of modified molten-salt MCN and improved the photocatalytic performance. Compared with pure MCN prepared by the molten salt method, Fe-doped MCN has superior photocatalytic ability. The best photocatalytic performance was obtained over 0.5Fe-MCN composites. Photolysis of seawater under sunlight produced 1.41 mmol h- 1g- 1 H2 and 0.12 mmol h- 1g- 1 O2, which is 5.54 and 7.6 times higher than BCN, respectively. In addition, glucosamine hydrochloride as a sacrificial agent can be completely decomposed while producing 15.84 mu mol h- 1g- 1 H2. This study provides a new research direction for photolysis of seawater for hydrogen and oxygen production.