A novel strategy is proposed to in situ synthesize hierarchically porous g-C₃N₄ foam (FCN) with no carbon residue by low-cost polyurethane sponge as single template. The porous system consists of interconnected micron- (1–2 μm) and nano-scale (20–80 nm) pores, which is usually constructed tediously. For visible light catalysis, the FCN with unique hierarchical pores possesses higher efficiency for H₂ generation (8 times) and phenol degradation (4 times) over pristine g-C₃N₄ due to the increased BET surface area, accelerated mass transfer and improved efficiency of exciton generation and dissociation, which all derive from the hierarchical pore system. Further, an optical simulation is initially adopted to illustrate the effect of the hierarchical porosity with micron- and nano-scale pores on the ability of light absorption and penetration over FCN and an energy-absorption-based explanation is proposed to deeply explain the enhanced photocatalytic activity, which opens a window to directly understand the relationship of the enhanced photocatalytic activities and absorbed light energy increased by the hierarchical pores system.

提出了一种新颖的策略，以低成本聚氨酯海绵作为单一模板原位合成无碳残留的分层多孔gC ₃ N ₄泡沫（FCN）。多孔系统由相互连接的微米（1-2μm）和纳米级（20-80 nm）的孔组成，通常结构繁琐。对于可见光催化，与原始gC ₃ N _4相比，具有独特层次孔的FCN具有更高的H ₂生成效率（8倍）和苯酚降解效率（4倍）。由于增加了BET表面积，加速了质量转移，提高了激子产生和解离的效率，这一切都源于分层孔隙系统。此外，最初采用光学模拟来说明具有微米级和纳米级孔隙的分层孔隙对光在FCN上的吸收和渗透能力的影响，并提出了基于能量吸收的解释来深入解释增强的光催化作用。活性，这将打开一个窗口，直接了解增强的光催化活性与由分层孔隙系统增加的吸收光能之间的关系。