Cubic mesoporous carbon nitride polymers with large cage-type pores for visible light photocatalysis

Large pore three-dimensional cage-type mesoporous carbon nitride semiconductors were successfully synthesized by employing SBA-16 templates which are prepared by hydrothermal methods at higher temperatures. These samples were characterized by using various techniques, and their photocatalytic H2 production properties were investigated under visible light (λ > 420 nm) irradiation. The results have shown that the textural parameters of the carbon nitride semiconductors can be easily tuned by simple adjustment of the synthesis temperature of the template SBA-16 silica, and carbon nitride semiconductors can be truly reversely replicated from the cubic structure of the template silica synthesized at a temperature of 180 and 200 °C. The large pore cage-type mesoporous carbon nitride semiconductor cast from mesoporous silica at the hydrothermal temperature of 200 °C exhibits a remarkably enhanced photocatalytic activity towards hydrogen evolution, as compared to either disordered mesoporous g-CN or bulk g-CN prepared by our previous synthetic approaches.