Poly(ionic liquid)-Assisted Synthesis of Open-Ended Carbon Nitride Tube for Efficient Photocatalytic Hydrogen Evolution under Visible-Light Irradiation

Carbon nitride is a promising candidate for photocatalysis but exhibits the limited activity due to the poor mass rate and insufficient light harvesting properties. Herein, an efficient synthesis approach is reported to fabricate the hierarchical porous carbon nitride with an open-ended tubular structure by using a poly(ionic liquid) as solvent and templates for the first time. The texture and morphology of carbon nitride are controlled by changing the concentration and type of poly(ionic liquid)s. The novel micro-nanostructure of carbon nitride benefits the enhancement of light harvesting properties and the exposure of active sites. Besides, the open-ended tubular structure of CN-75 accelerates electron transfer along the longitudinal dimension, which efficiently improves the photogenerated charge carrier separation rate. Benefiting from the unique advantages of our template method, the novel tubular carbon nitride CN-75 reveals a significantly enhanced hydrogen evolution rate (207.9 μmol h–1) under visible-light irradiation, which is about 16.9 times as high as that of pristine carbon nitride. This work provides a new way to fabricate the novel materials with a hierarchical texture by using poly(ionic liquid)s for diverse applications in environmental and energy fields.