Construction of 3DOM Carbon Nitrides with Quasi‐Honeycomb Structures for Efficient Photocatalytic H₂ Production

Abstract

Constructing porous nanostructures is an effective strategy for improving photocatalytic activity and separating charge carriers in the visible area. In this paper, the macroporous g‐C3N4 photocatalyst with a quasi‐honeycomb structure was successfully built with a simple thermal condensation‐colloidal template way for photocatalytic hydrogen production. The microstructure, electron transfer and optical absorption capability of quasi‐honeycomb g‐C3N4 have been methodically investigated. The obvious structural susceptibility to light catching, and charge carriers separation and transfer were realized. These results illustrated that compared with bulk g‐C3N4, the optimized g‐C3N4 photocatalyst with a quasi‐honeycomb structure had the higher H2 release rate of 395 μmol h−1, the corresponding apparent quantum efficiency (AQE) of 6.27 %, and excellent cycle stability. This work demonstrates that the quasi‐honeycomb structures can be designed and used to synthesize highly‐efficient g‐C3N4 nanoarchitectures, providing a reference for enhancing photocatalytic H2 evolution performance.

Multiple ordered porous honeycombed g-C3N4 with carbon ring in-plane splicing for outstanding photocatalytic H2 production

“…Quantum connement induced by the ultrathin wall and the multiple reections of incident light in the 3D honeycomb structure are conducive to achieving a much narrower band gap and a more negative band edge. 15,26 Furthermore, the hybridization of the triazine/C r system with extended p-conjugation can efficiently delocalize the electrons and thus cause the band gap to narrow. Additionally, the XPS valence band (VB) spectra were recorded to determine the VB level of the samples, and their values are shown in Fig.…”

“…6,7 However, pristine bulk g-C 3 N 4 exhibits a low hydrogen production rate (HER) and apparent quantum efficiency (AQE) because of its low specic surface area, poor electronic properties, insufficient light absorption and high recombination rate of photogenerated electron-hole pairs. 4,8 Accordingly, numerous modication methods have been explored to improve the photocatalytic activity of g-C 3 N 4 , such as element doping, 9,10 exfoliation, [11][12][13] multiple types of nanostructural designs, [14][15][16][17][18][19] coupling with other semiconductors and construction of metal-free heterojunctions. [20][21][22] The simultaneous morphology control and in-plane modication of highperformance g-C 3 N 4 with high yield is still challenging.…”

A Review on the Bioinspired Photocatalysts and Photocatalytic Systems

“…Reproduced with permission. [ 46 ] Copyright 2018, Wiley‐VCH. h) Illustration, distributions of electromagnetic energies and UV–vis absorption of the invop TiO 2 photonic crystal.…”

“…Inspired by honeycomb in nature, a macroporous g‐C 3 N 4 photocatalyst with honeycomb structure (Figure 3g) [ 46 ] with excellent photocatalytic hydrogen production performance was successfully constructed by a thermal condensation colloidal template method. The obvious structural advantage in light capture as well as the enhanced carriers’ separation were realized.…”

Dual cocatalysts decorated three dimensionally ordered mesoporous g‐C3N4 with homogeneous wall thickness for enhanced photocatalytic performance

“…Generally, g‐C 3 N 4 with the layered structure has a narrow visible‐light response range, high electron–hole recombination probability, low quantum efficiency and low specific surface area, resulting in its poor photocatalytic activity. Therefore, it is of great interest to design and fabricate g‐C 3 N 4 materials with three dimensionally ordered mesoporous (3DOM) architecture, because the structure advantage can enhance the visible‐light harvesting ability, facilitate separation/transfer of charge carries and improve the lifetime of electrons . Especially, it is a common strategy to give photocatalysts with 3DOM architecture through using silica nanospheres with three dimensionally closed‐packed structure as hard templates .…”