Dimensionally integrated nanoarchitectonics with Cu nanoparticles embedded in g-C3N4 nanosheets for efficient photocatalytic hydrogen generation and dye degradation

High-efficiency and sustainable non-noble metal cocatalyst can reduce the reaction barrier of photocatalysis or electrocatalysis to promote the hydrogen evolution reaction, which provides a feasible method for large-scale hydrogen production. A one-step thermal polymerization method was developed to successfully incorporate copper (Cu) into graphite nitride carbon (g-C3N4) through a mechanochemical pre-treatment and subsequently thermal polymerization. The synthesis controlling is a key to arrange the distribution of Cu nanoparticles in g-C3N4 nanosheets. Photocatalytic hydrogen generation tests were carried out for Cu incorporated g-C3N4 nanosheets obtained at different temperatures. Cu incorporated g-C3N4 at 680 °C (CCN-680) revealed the best H2 generation rate of 2985 μmol g-1 h−1, which was 12.7 times of that of pure g-C3N4 nanosheets obtained at same temperature. Furthermore, the degradation of methylene blue (MB) indicated that sample CCN-680-3 with optimized Cu ratio revealed enhanced performance, in which the degradation rate of MB increased from 80 to 97 % within 60 min. The introduction of Cu narrowed the band gap of g-C3N4 nanosheets, expanded light response in visible region, and finally improved greatly the separation efficiency of photogenerated charge carriers. These results are significant for highly efficient and stable photocatalysts.