Synthesizing the High Surface Area g-C3N4 for Greatly Enhanced Hydrogen Production

Abstract

Adjusting the structure of g-C3N4 to significantly enhance its photocatalytic activity has attracted considerable attention. Herein, a novel, sponge-like g-C3N4 with a porous structure is prepared from the annealing of protonated melamine under N2/H2 atmosphere (PH-CN). Compared to bulk g-C3N4 via calcination of melamine under ambient atmosphere (B-CN), PH-CN displays thinner nanosheets and a higher surface area (150.1 m2/g), which is a benefit for shortening the diffusion distance of photoinduced carriers, providing more active sites, and finally favoring the enhancement of the photocatalytic activity. Moreover, it can be clearly observed from the UV-vis spectrum that PH-CN displays better performance for harvesting light compared to B-CN. Additionally, the PH-CN is prepared with a larger band gap of 2.88 eV with the Fermi level and conduction band potential increased and valence band potential decreased, which could promote the water redox reaction. The application experiment results show that the hydrogen evolution rate on PH-CN was nearly 10 times higher than that of B-CN, which was roughly 4104 μmol h−1 g−1. The method shown in this work provides an effective approach to adjust the structure of g-C3N4 with considerable photocatalytic hydrogen evolution activity.

Carbonized Melamine Cyanurate as a Palladium Catalyst Support for the Dehydrogenation of N-heterocyclic Compounds in LOHC Technology

“…According to the literature data [49,54,55], different ratios of the intensities of the (100) and (002) reflections are typical for carbon nitrides with different order degrees. For strongly disordered carbon nitrides, the intensity of the (100) reflection is strongly reduced compared to the (002) reflection or may even be completely absent.…”

High surface area, spongy graphitic carbon nitride derived by selective etching by Pt and Ru nanoparticles in hydrogen

“…Apart from chemical methods of exfoliation, thermal exfoliation is also applied. It allows for an increase in SSA of g-C 3 N 4 to 150 m 2 g -1 [13] and sometimes even (repeating exfoliation three times) to 513 m 2 g -1 [12]. However, it should be pointed out that the final product yield did not exceed 6% in the latter case.…”

“…In a number of potential applications such as photo-, electro-, heterogeneous-catalysis, and gas storage, a high SSA is essential. Hence, attempts were made to synthesize the high-surface area of g-C 3 N 4 by using hard or soft template methods [7][8][9][10], by exfoliation into nanosheets [11][12][13][14] or by heteroatom doping [15,16]. The most commonly used method is the hard template method based on the use of high-surface area inorganic material, which acts as the matrix on which g-C 3 N 4 is synthesized.…”

The Construction of an α-F2O3/Tubular g-C3N4 Z-Scheme Heterojunction Catalyst for the Efficient Photocatalytic Degradation of Tetracycline

“…have been prepared successfully [20][21][22][23][24]. Wang et al prepared novel, spongy g-C 3 N 4 with a porous structure via protonated melamine annealing under an N 2 /H 2 atmosphere, showing thinner nanosheets and a larger surface area [25]. Yang et al prepared flower-like P-doped graphitic carbon nitride (g-C 3 N 4 ) with a large surface area and high porosity via a facile thermal copolymerization method [26].…”