Simulation-guided synthesis of graphitic carbon nitride beads with 3D interconnected and continuous meso/macropore channels for enhanced light absorption and photocatalytic performance

Abstract

An optical simulation is adopted to examine the effects of the pore channels with different sizes and architectures on the ability of light absorption in photocatalysts. The simulation results are utilized to guide the synthesis of a novel porous graphitic carbon nitride (g-C₃N₄) material in bead form, using millimeter-scale porous SiO₂ beads as a template. The obtained g-C₃N₄ beads possess a unique porous architecture with 3D interconnected and continuous meso/macropore channels at 30–90 nm in size, which is identical to the simulation result. Compared with pristine g-C₃N₄, the prepared material exhibits significantly enhanced visible light-induced catalytic performances for H₂ evolution (8 times), photoreduction of nitrobenzene (3 times) and degradations of rhodamine B (4 times), methyl orange (2 times) and phenol (3 times). The unique pores and skeleton structures not only promote light penetration inside the material and light absorption at the edge of pore channels, but also improve mass transfer and inhibit the recombination of photogenerated electrons and holes. Moreover, this optical simulation approach could be adopted to guide the synthesis of other porous photocatalysts, and to verify their light absorption and infiltration properties in photocatalysis.