Maleic hydrazide-based molecule doping in three-dimensional lettuce-like graphite carbon nitride towards highly efficient photocatalytic hydrogen evolution

ACS Appl. Mater. Interfaces

Zhou

et al. 2021

g-C3N4 is a visible-light photocatalyst with a suitable band gap and good stability. Moreover, g-C3N4 is considered to be earth-abundant, which makes it an appealing photocatalyst. However, due to its small specific surface area, low utilization of visible light, and high photogenerated electron–hole pair recombination rate, the photocatalytic activity of g-C3N4 remains unsatisfactory. In this work, a highly efficient nonmetallic photocatalyst, i.e., g-C3N4 doped with uracil (denoted U-C3N4) was successfully developed. Based on the various characterizations and calculations, it is shown that the triazine group in g-C3N4 is replaced with the diazine group in uracil. This occurrence leads to the formation of a new electron-transfer pathway between triazine groups, which can promote the separation of photogenerated electrons and holes. Concurrently, due to the ultrathin structure of the as-prepared U-C3N4, the material possessed a larger specific surface area than pristine g-C3N4, which can provide more active sites. Furthermore, the transfer pathway between the electron and hole was also shortened, and the recombination of the electron and hole was inhibited. According to the results, an optimal hydrogen evolution rate of 31.7 mol h–1 g–1 was achieved by U-C3N4, which is 5.1 times higher as compared to that achieved by pristine g-C3N4 (6.26 mol h–1 g–1). For the photocatalytic degradation of rhodamine B, the reaction rate constant of U-C3N4 (11.3 × 10–2 min–1) is about 5.5 times that of g-C3N4 (2.07 × 10–2 min–1). Furthermore, the uracil-doped catalyst was also able to demonstrate good stability after five successive runs.

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Uracil-Doped Graphitic Carbon Nitride for Enhanced Photocatalytic Performance

Zhan

ACS Appl. Mater. Interfaces

Zhou

et al. 2021

“…Fortunately, the assembly of the basic structure unit into three dimensional (3D) hierarchical structures provide a useful tactic to endow the g-C 3 N 4 with an interconnected open-framework and a greater exposed surface. 24–29 For example, 3D photocatalyst assemblies of 2D nanosheets presented both an increased surface area and maximum utilization of photons. 16 However, 3D g-C 3 N 4 architectures constructed using 1D tubes has been much less reported.…”

Section: Introductionmentioning

confidence: 99%

The biopolymer-assisted synthesis of assembled g-C₃N₄ open frameworks with electron delocalization channels for prompt H₂ production

Liu

et al. 2022

Catal. Sci. Technol.

“…As a photocatalyst, polymeric g-C 3 N 4 has the advantages of suitable band structure, good chemical stability, nontoxicity, low cost, easy preparation, etc. [26][27][28][29][30][31][32][33] However, because of low specific surface area, limited utilization of visible light and excessively high photogenerated carrier recombination rate of g-C 3 N 4 , [34][35][36][37][38][39][40][41] its photocatalytic H 2 production performance has been limited to date.…”

Section: Introductionmentioning

confidence: 99%

Facile one‐pot pyrolysis preparation of SnO₂/g‐C₃N₄ composites for improved photocatalytic H₂ production

Cai

J of Chemical Tech & Biotech

Shi

et al. 2022

Self Cite

BACKGROUND Graphitic carbon nitride (g‐C3N4) has attracted extensive attention as a typical photocatalyst. However, g‐C3N4 still needs to be modified to obtain enhanced hydrogen production activity. RESULTS Here, SnO2/g‐C3N4 composites were prepared by a facile one‐pot pyrolysis method, and showed enhanced visible‐light‐driven photocatalytic H2 production activities with the highest value of 241 μmol h−1 g−1, which was about four times that of pure polymeric g‐C3N4. The facile one‐pot pyrolysis method not only promoted effective coupling between g‐C3N4 and SnO2, but also adjusted the photocatalytic performance‐related physicochemical properties of polymeric g‐C3N4. The reduction of particle sizes of g‐C3N4 promoted the migration of photogenerated carriers to the surface and the introduction of SnO2 as electron transport material promoted the transfer of photogenerated charge carriers from g‐C3N4 host photocatalyst to metallic Pt cocatalyst, synergistically restraining the recombination of photogenerated carriers. Moreover, the increased specific surface areas and pore volumes enriched the reactive sites and facilitated the mass transfer of reactants, thus accelerating the redox reactions. Furthermore, the enhanced light absorption promoted the generation of photogenerated carriers which was beneficial for photocatalytic reactions. CONCLUSIONS This work provides an effective reference for the application of Sn species in the modification of photocatalysts, especially polymeric g‐C3N4. © 2022 Society of Chemical Industry.