Facile synthesis of three-dimensional hollow porous carbon doped polymeric carbon nitride with highly efficient photocatalytic performance

Developing a high photocatalytic performance metal-free catalyst with both a fast H₂ evolution rate and efficient pollutant degradation efficiency is an urgent requirement to solve the challenges associated with water pollution and energy crises. Herein, we first report a novel and feasible strategy to develop a highly efficient three-dimensional (3D) hollow porous C-doped polymeric carbon nitride (CPCN) catalyst based on the combination of morphological controls and in situ C doping. The as-synthesized CPCN catalysts show outstanding H₂ production activity (16.69 mmol g⁻¹h⁻¹) as well as a high degradation rate (20.3 × 10⁻³ min⁻¹) of diclofenac under visible light. The characterization and density functional theory calculation results indicate that the 3D hollow porous structure can not only endow the CPCN catalyst with a large surface area and countless exposed active sites but also promote the substrate adsorption reaction and maintain its structural stability. Simultaneously, in situ C doping can also enhance the light absorption and promote the charge transfer and separation of the CPCN sample. Consequently, excellent photocatalytic performance was achieved and the proposed enhanced mechanism of photocatalytic activity was also elucidated. This work may shed light on the development of highly efficient metal-free catalysts.