CuSe nanoplates horizontally implanted on C-doped g-C3N4 nanosheets for H2O splitting and highly selective CH4 conversion

To obtain highly efficient two-dimensional (2D)/2D heterostructure photocatalysts, a solvothermal synthetic route was developed to grow layered hexagonal CuSe nanoplates with high crystallinity on superior thin C-doped g-C 3 N 4 nanosheets fabricated via two-step thermal polymerization at high temperature. Meanwhile, Mott-Schottky junction can supply The loading of CuSe nanoplates is one of the keys to form a Mott-Schottky junction, in which the photogenerated electrons were transferred to MoSe utilizing charge carrier separation. Thus, latered CuSe/g-C 3 N 4 junction revealed enhanced photocatalytic H 2 evolution efficiency of 187.8 μmolg -1 h -1 which is 12.3 times of that of pure g-C 3 N 4 nanosheets). In addition to the Mott-Schottky junction formed using the combination of CuSe and g-C 3 N 4 nanosheets, the much higher conductivity of CuSe (in comparison with that of g-C 3 N 4 ) was conducive to the enhanced photogenerated electron transport in the composite system. The sample fabricated utilizing optimized parameters reveals a CH 4 evolution rate of 11.5 μmolg -1 h -1 (via CO 2 conversion) with a reasonably high CH 4 selectivity of 76% in case of no co-catalyst incorporation, for which improved light harvesting ability, enhanced photogenerated charge carrier separation/transfer and CO 2 adsorbability due to the presence of CuSe nanocomponents play the key roles. The 2D/2D heterostructures constructed using highly crystalline CuSe nanoplates and g-C 3 N 4 nanosheets with well-developed interfaces are advantaged by the effectively improved charge carrier separation and transport efficiencies. These results offer important insights on construction of novel photocatalysts for attaining high photocatalytic performances.