A 3D Hierarchical Pancake-Like Porous Carbon Nitride for Highly Enhanced Visible-Light Photocatalytic H2 Evolution

Abstract

Polymeric carbon nitride is a fascinating visible-light-response metal-free semiconductor photocatalyst in recent decades. Nevertheless, the photocatalytic H2 efficiency is unsatisfactory due to the insufficient visible-light harvesting capacity and low quantum yields caused by the bulky structure seriously limited its applications. To overcome these defects, in this research, a 3D hierarchical pancake-like porous carbon nitride (PPCN) was successfully fabricated by a facile bottom-up method. The as-prepared photocatalyst exhibit enlarged surface area, enriched reactive sites, improved charge carrier transformation and separation efficiency, and expanded bandgap with a more negative conduction band towardan enhanced reduction ability. All these features synergistically enhanced the photocatalytic H2 evolution efficiency of 3% Pt@PPCN (430 µmol g−1 h−1) under the visible light illumination (λ ≥ 420 nm), which was nine-fold higher than that of 3% Pt@bulk C3N4 (BCN) (45 µmol g−1 h−1). The improved structure and enhanced photoelectric properties were systematically investigated by different characterization techniques. This research may provide an insightful synthesis strategy for polymeric carbon nitride with excellent light-harvesting capacity and enhanced separation of charges toward remarkable photocatalytic H2 for water splitting.

One-pot synthesis of defect engineered carbon nitride for highly efficient visible light photocatalysis

“…7 Many strategies have been explored to address these drawbacks of CN, including heterojunction formation, [8][9][10] defect engineering (such as doping 11,12 and modifying intrinsic vacancies 13,14 ) and morphological design. 15,16 Modication of CN by doping with elements such as S, 17,18 P 19,20 and B 21 is regarded as a facile and effective approach to overcome the inefficient light harvesting of CN and alter the electronic structure, thereby maximising its potential for photocatalytic applications. However, the introduction of foreign atoms can form recombination centres for photoinduced charge carriers or induce thermal instabilities.…”

Towards Green, Enhanced Photocatalysts for Hydrogen Evolution

“…A new 3D porous carbon nitride catalyst has been proposed by Qiu et al [1]. The material was synthesized by a simple bottom-up procedure entailing self-assembly of a melamine-cyanuric acid complex followed by ethanol and glycerol intercalation prior to calcination.…”