Enhanced photocatalytic activity of rare earth (Yb, Nd and Ce)-doped g-C3N4 nanosheets for the degradation of organic dyes under visible light

g-C 3 N 4 and rare earth (RE)-doped (Yb, Nd and Ce) g-C 3 N 4 nanosheets were synthesized by a thermal method. The remarkable effects of RE doping on the structural, morphological, and optical properties of g-C 3 N 4 were investigated using XRD, FT-IR, SEM, BET, XPS, UV–Vis, PL, EIS and Mott–Schottky characterization techniques. The photocatalytic activities of RE doped g-C 3 N 4 nanosheets for different dyes were improved compared with g-C 3 N 4 under visible light irradiation, among which Ce/g-C 3 N 4 showed outstanding performance. Due to the doping of RE, it modulates the electronic structure of pristine g-C 3 N 4 and broadens its optical absorption range. In addition, a possible mechanism of photocatalytic degradation of dyes was propounded by free radical trapping experiments. This work may provide a reference for the rational design of photocatalysts and inspiration for the photocatalytic mechanism.