Hierarchical macro-mesoporous g-C3N4 with inverse opal structure and vacancy for high-efficiency solar energy conversion and environmental remediation
Hierarchical macro-mesoporous structures with an efficient mass transfer and light harvesting offer great advantages for photocatalysis. Nitrogen vacancy modified ordered hierarchical macro-mesoporous g-C3N4 (Nv MM CN) was fabricated by a dual-templating method combining ordered SiO2 colloidal crystal and NH4Cl. The as prepared Nv MM CN was applied for photocatalytic degradation of antibiotics and production of hydrogen. Nv MM CN showed 27 times higher photocatalytic degradation efficiency and 7.5 times higher hydrogen production than bulk g-C3N4 (Bulk CN) under visible light irradiation. The 3D well interconnected macro-mesoporous structure and porous system accelerated adsorption as well as reaction rate and the inverse opal photonic crystals provided multiple scattering effect to strengthen light absorption. Meanwhile, the introduction of nitrogen vacancy acted as a separation center to capture electrons or holes to improve the separation efficiency of charges. This efficient, stable, and environmentally friendly visible light-driven Nv MM CN may be an alternate for effective implementation in wide-ranging energy and environmental applications.