Cross-Linked Graphitic Carbon Nitride with Photonic Crystal Structure for Efficient Visible-Light-Driven Photocatalysis

Highly cross-linked graphitic carbon nitride has been prepared by a thermal copolymerization of dicyanodiamide with tetramethylammonium salts. The cross-linking can be evidenced by (i) increased C/N ratio without new carbon species, (ii) decreased specific surface area, and (iii) Tyndall effect after dissolution in concentrated sulfuric acid. The cross linked graphitic carbon nitride with photonic crystal structure has highly efficient photocatalytic activity for water splitting under visible light due to the synergistic enhancement by the greatly suppressed photoluminescence, red-shifted absorption edges, strong inner reflections, and effective PCs stop band overlaps. It exhibits an enhanced photodegradation kinetic of methyl orange and a high visible-light-driven hydrogen-evolution rate of 166.9 imol (25 times higher than that of the pristine graphitic carbon nitride counterpart). This work presents a facile method for designing and developing high-performance graphitic carbon nitride photocatalysts, providing a broad range of application prospects in the fields of electronics and energy conversion.