Facile One-Step Synthesis of Hybrid Graphitic Carbon Nitride and Carbon Composites as High-Performance Catalysts for CO₂ Photocatalytic Conversion

Abstract

Utilizing and reducing carbon dioxide is a key target in the fight against global warming. The photocatalytic performance of bulk graphitic carbon nitride (g-C3N4) is usually limited by its low surface area and rapid charge carrier recombination. To develop g-C3N4 more suitable for photocatalysis, researchers have to enlarge its surface area and accelerate the charge carrier separation. In this work, novel hybrid graphitic carbon nitride and carbon (H-g-C3N4/C) composites with various carbon contents have been developed for the first time by a facile one-step pyrolysis method using melamine and natural soybean oil as precursors. The effect of carbon content on the structure of H-g-C3N4/C composites and the catalytic activity for the photoreduction of CO2 with H2O were investigated. The results indicated that the introduction of carbon component can effectively improve the textural properties and electronic conductivity of the composites, which exhibited imporved photocatalytic activity for the reduction of CO2 with H2O in comparison with bulk g-C3N4. The highest CO and CH4 yield of 22.60 μmol/g-cat. and 12.5 μmol/g-cat., respectively, were acquired on the H-g-C3N4/C-6 catalyst with the carbon content of 3.77 wt % under 9 h simulated solar irradiation, which were more than twice as high as that of bulk g-C3N4. The remarkably increased photocatalytic performance arises from the synergistic effect of hybrid carbon and g-C3N4.

Silver Nanoparticles Modified Graphitic Carbon Nitride Nanosheets as a Significant Bifunctional Material for Practical Applications

“…3–8 % below 100 ° C should be associated with desorption of the physisorbed water. Whereas, the notable weight‐losses between 500 to 700 ° C with centering peak temperature following the ascending order: GCN < NH 2 /GCN < Ag‐NH 2 /GCN may be unambiguously due to decomposition or combustion of graphitized carbon as well as incorporated amines in NH 2 /GCN . Additional elemental analysis by the ICP‐AES technique confirmed the presence of silver element in the Ag‐NH 2 /GCN nanocomposite material with a content of 3780 ppm (i. e., about 0.38 wt%).…”

Nanostructured Carbon Nitrides for CO2 Capture and Conversion

“…could also be hybridized on to the g‐C 3 N 4 as a co‐catalyst to prompt charge‐carrier separation, kinetic transfer and this strategy is conventionally employed for hybrids of C 3 N 4 and semiconductors to enhance the photocatalytic efficiency of the hybrids . Conductive carbons such as graphene and amorphous carbon are also good additives to facilitate electron–hole separation in g‐C 3 N 4 /carbon composites for CO 2 photoreduction . The g‐C 3 N 4 could also be hybridized with CO 2 adsorbents such as layered double hydroxides and metal–organic frameworks (MOFs) considering that the adsorbents would provide a CO 2 ‐rich environment (Figure D–G) .…”

Soft‐Template Synthesis of Hybrid Carbon and Carbon Nitride Composites with Enhanced Photocatalytic Activity for the Degradation of Methylene Blue under Visible Light

“…However, the N 1s peaks of C/CN-P123-0.8 present a slight positive shift relative to that of the C/CN-P123-0, which should be ascribed to the more doping carbon in the g-C 3 N 4 . The O 1s spectrum of C/CN-P123-0 can be fitted into two peaks at 531.3, 532.6 eV, which can be assigned to C OH and adsorbed O 2 , respectively [16]. In case of C/CN-P123-0.8, the new peak at 533.2 eV can be attributed to the generation of N C O bonds, meaning that the oxygen can directly bond with the sp 2 -hybridized C in C/CN-P123-0.8 [27].…”

“…Wang et al . have prepared C/CN by heating the mixture of melamine and soybean oil, which can be used as high‐performance catalysts for CO 2 photocatalytic conversion . Just recently, our research group has exploited a novel approach to synthesize C/CN by using partially formaldehyde‐modified dicyandiamide as a precursor.…”

“…Xu et al have obtained C/CN through thermal treatment of the mixtures of urea and glucose [15], the enhanced photocatalytic performance originates not only from the enlarged surface area and extended visible light response range but also from the effectively separated photo-generated charge carriers. Wang et al have prepared C/CN by heating the mixture of melamine and soybean oil, which can be used as high-performance catalysts for CO 2 photocatalytic conversion [16]. Just recently, our research group has exploited a novel approach to synthesize C/CN by using partially formaldehyde-modified dicyandiamide as a precursor.…”