Compressible and Recyclable Monolithic g-C3N4/Melamine Sponge: A Facile Ultrasonic-Coating Approach and Enhanced Visible-Light Photocatalytic Activity

Abstract

Powdery photocatalysts seriously restrict their practical application due to the difficult recycle and low photocatalytic activity. In this work, a monolithic g-C3N4/melamine sponge (g-C3N4/MS) was successfully fabricated by a cost-effective ultrasonic-coating route, which is easy to achieve the uniform dispersion and firm loading of g-C3N4 on MS skeleton. The monolithic g-C3N4/MS entirely inherits the porous structure of MS and results in a larger specific surface area (SSA) than its powdery counterpart. Benefit from this monolithic structure, g-C3N4/MS gains more exposed active sites, enhanced visible-light absorption and separation of photogenerated carriers, thus achieving noticeable photocatalytic activity on nitric oxide (NO) removal and CO2 reduction. Specifically, NO removal ratio is as high as 78.6% which is 4.5 times higher than that of the powdery g-C3N4, and yield rate of CO and CH4 attains 7.48 and 3.93 μmol g−1 h−1. Importantly, the features of low-density, high porosity, good elasticity, and firmness, not only endow g-C3N4/MS with flexibility in various environmental applications, but also make it easy to recycle and stable for long-time application. Our work provides a feasible approach to fabricate novel monolithic photocatalysts with large-scale production and application.

Effect of calcination temperature, pH and catalyst loading on photodegradation efficiency of urea derived graphitic carbon nitride towards methylene blue dye solution

“…42 The other smaller peak around 13.1 could be indexed to (100) plane which corresponds to in-planar structural packing motif. [43][44][45] The (100) peak was found to be intense and narrow for g-C 3 N 4 samples at 550 to 650 C, indicative of higher degree of polymerisation. The broader peak for samples at 450 and 500 C is indicative of low degree of polymerization of g-C 3 N 4 .…”

Photocatalyst-Incorporated Cross-Linked Porous Polymer Networks

“…This novel photoactive composite has shown decent photooxidation ability according to NO photoremoval experiment (optimum activity = 78.6%) besides effective CO 2 photoreduction in comparison to powder g-C 3 N 4 . 118 This is a post-embedding technique yet the potential leaching of g-CN particles should be investigated in detail.…”

Research Progress on Photocatalytic/Photoelectrocatalytic Oxidation of Nitrogen Oxides

“…Li et al [64] reported a C 3 N 4 supported Pd nanoparticles catalyst (PdCN) for photocatalytic oxidation of NO x ; this PdCN was found to have a better purification effect on NO in the air, reaching a maximum of 51.5% in the first 5 min, followed by stabilization at 44.9%. Yang et al [71] successfully synthesized a g-C 3 N 4 /melamine sponge (g-C 3 N 4 /MS) using the ultrasonic coating method with g-C 3 N 4 uniform dispersion and immobilization on the melamine skeleton (Fig. 8a-d).…”