Self-Assembled Mesoporous Carbon Nitride with Tunable Texture for Enhanced Visible-Light Photocatalytic Hydrogen Evolution

Abstract

Mesoporous carbon nitride with novel morphology has been successfully fabricated by using ionic liquid and supramolecular precursor cyanuric acid-melamine complex as the template and precursor, respectively. The texture of carbon nitride is controlled by adjusting the ionic liquid concentration and type. The results find that a disordered hollow carbon nitride box morphology with pores in the wall can be obtained under lower IL1 concentration. With increasing of ionic liquid content, the texture turns to be a layered structure. The disordered nanosheets and hollow tube with large pores in the shell can be fabricated by using IL-2 and IL-3 as templates, respectively. Besides, as-prepared mesoporous carbon nitride samples display the excellent light harvesting properties and fast separation rate of photogenerated carrier. Moreover, mesoporous carbon nitride CN-0.1 exhibits a higher photocatalytic hydrogen evolution rate (120.3 μmol h–1) under visible light irradiation owing to the special structure and the presence of multiple mesopores, which is approximately 25.6, 1.7 times as high as that of bulk carbon nitride calcined by melamine and CN, respectively. Furthermore, photocatalytic RhB degradation rate is enhanced by using CN-0.1 compared with pure CN. This method provides more insights into designing novel visible light driven photocatalysts by using ionic liquids.

Hollow polymer dots: nature-mimicking architecture for efficient photocatalytic hydrogen evolution reaction

“…S15 †), showing about 50 times decrease in the photocatalytic activity as compared to hollow Pdots with 50 nm. Note that hollow Pdots as photocatalysts have advantages, such as large light harvesting, high specic surface area and spatial anisotropic charge separation, [53][54][55][56][57] which signicantly enhances photocatalytic activity of the hollow structure.…”

Synthesis of g‐C3N4 Nanosheets by Using a Highly Condensed Lamellar Crystalline Melamine–Cyanuric Acid Supramolecular Complex for Enhanced Solar Hydrogen Generation

“…The hydrogen bonds significantly reduce the sublimation of these molecules (melamine and cyanuric acid), thus promoting their polycondensation . Additionally, the distinctive structure of MCS complex leads to the formation of carbon nitride materials with a high surface area and a porous structure . Moreover, compared to previous hard‐template approaches, the template for carbon nitride synthesis becomes simpler through altering the structure of the MCS complex .…”

“…Additionally, the distinctive structure of MCS complex leads to the formation of carbon nitride materials with a high surface area and a porous structure . Moreover, compared to previous hard‐template approaches, the template for carbon nitride synthesis becomes simpler through altering the structure of the MCS complex . This can be done easily by choosing the appropriate solvents and precursor ratios for the synthesis process because of the sensitive dependence of the hydrogen‐bonded assembly in MCS on the nature of solvents used .…”

Ionic liquid‐assisted synthesis of defect‐rich BiOI with controllable structure and high surface area for excellent visible‐light photocatalytic activity

“…[ 1–4 ] Photocatalysis technology exhibits great promise for water splitting, CO 2 photoreduction and degradation of organic pollutants after the finding of water splitting by using TiO 2 as electrode. [ 5–8 ] Many preparation methods have been developed to fabricate novel effective photocatalysts, including element doping, heterostructure construction and morphology modification. [ 9–13 ] In spite of the achievements achieved, there is still much room for improvement of photocatalytic efficiency owing to the low solar light utilization and fast recombination rate of photogenerated carriers.…”

“…Besides, the previous works certify the significance of reaction condition. [ 5,32 ] Especially, changing the pH during the reaction process can affect the self‐assembly behavior of ionic liquid, influence the growth direction and rate of the layered structure, then affect the facet exposure of photocatalysts, and finally adjust the photocatalytic ability.…”