Magnesiothermic reduction synthesis of N-deficient g-C3N4 with enhanced photocatalytic performance under visible light

The N-deficient g-C3N4 (DCN) materials were prepared via a magnesiothermic reduction of g-C3N4, which exhibited significantly enhanced visible-light absorption and photocatalytic performance compared to pristine g-C3N4. In particular, the DCN sample with a g-C3N4:Mg mass ratio of 1:0.2 in the precursor mixture provided the most efficient RhB degradation of over 99%, nearly six-time higher than that of pure g-C3N4. This is attributed to the widened visible-light absorption and efficient separation of generated charge carriers due to the presence of nitrogen vacancies in DCN. A proposed photocatalytic mechanism and the pH effect on rhodamine B photodegradation for DCN were obtained.