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In Situ Construction of Globe‐like Carbon Nitride as a Self‐Cocatalyst Modified Tree‐like Carbon Nitride for Drastic Improvement in Visible‐Light Photocatalytic Hydrogen Evolution
Author(s) -
Song Ting,
Zhang Piyong,
Zeng Jian,
Wang Tingting,
Ali Atif,
Zeng Heping
Publication year - 2017
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201700732
Subject(s) - photocatalysis , carbon nitride , photoluminescence , calcination , materials science , graphitic carbon nitride , photocurrent , carbon fibers , nitride , reversible hydrogen electrode , catalysis , chemical engineering , photochemistry , nanotechnology , chemistry , electrode , organic chemistry , electrochemistry , working electrode , composite material , optoelectronics , layer (electronics) , composite number , engineering
Abstract Photogenerated carriers possess high recombination efficiency in carbon–nitrogen materials, which results in lower photocatalytic H 2 evolution activity. By reviewing the literature, it was concluded that relying only on a structure‐controlled technique was insufficient to reduce the combination of photogenerated carriers without introducing a foreign material or element. Hence, bulk‐like g‐C 3 N 4 [CN (B)], globe/strip‐like g‐C 3 N 4 [CN (G/S)], and globe/tree‐like g‐C 3 N 4 [CN (G/T)] were in situ obtained through a facile calcination method. Similar to platinum (Pt) as a cocatalyst, globe‐like carbon nitride as a self‐cocatalyst was found to improve the separation efficiency of photogenerated carriers effectively. Interestingly, the hollow‐tree‐branch morphology of CN (G/T) effectively transmitted photogenerated holes, which thereby enhanced the photocatalytic H 2 evolution activity. The H 2 production rates of CN (G/S) and CN (G/T) were almost 10.7 and 18.3 times greater, respectively, than that of CN (B) without the addition of Pt as a cocatalyst. Notably, CN (G/S) and CN (G/T) displayed considerable rates of H 2 production in water relative to that shown by CN (B) (no activity) without the use of any sacrificial agent and by using Pt as a cocatalyst. CN (G/T) showed outstanding long‐term stability, as evidenced by seven cycle tests performed over 28 h. The charge separation and transfer process of the compounds were verified by photoluminescence (PL), time‐resolved PL spectroscopy, and photocurrent measurements.