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Constructing Built‐in Electric Field in Ultrathin Graphitic Carbon Nitride Nanosheets by N and O Codoping for Enhanced Photocatalytic Hydrogen Evolution Activity
Author(s) -
Yan Bo,
Du Chun,
Yang Guowei
Publication year - 2020
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201905700
Subject(s) - graphitic carbon nitride , photocatalysis , materials science , hydrogen production , hydrogen , electric field , quantum efficiency , band gap , nanostructure , nitride , water splitting , nanotechnology , carbon fibers , irradiation , photochemistry , chemical engineering , catalysis , optoelectronics , chemistry , layer (electronics) , physics , organic chemistry , quantum mechanics , composite material , composite number , engineering , nuclear physics
Codoping of N and O in ultrathin graphitic carbon nitride (g‐C 3 N 4 ) nanosheets leads to an inner electric field. This field restrains the recombination of photogenerated carriers and, thus, enhances hydrogen evolution. The layered structure of codoped g‐C 3 N 4 nanosheets (N‐O‐CNNS) not only provides abundant sites of contact with the reaction medium, but also decreases the distance over which the photogenerated electron–hole pairs are transported to the reaction interface. Quantum confinement in the ultrathin structure results in an increased bandgap and makes the photocatalytic reaction more favorable than bulk g‐C 3 N 4 . Under visible light irradiation, N‐O‐CNNS with 3 wt% Pt achieves a hydrogen evolution rate of 9.2 mmol g −1 h −1 and a value of 46.9 mmol g −1 h −1 under AM1.5 with 5 wt% Pt. Thus, this work paves the way for designing efficient nanostructures with increased separation/transfer efficiency of photogenerated carriers and, hence, increased photocatalytic activities.