Ligand-free Au nanoclusters/g-C3N4 ultra-thin nanosheets composite photocatalysts for efficient visible-light-driven photocatalytic H2 generation

• Published in: Journal of materials science Vol. 56; no. 24; pp. 13736 - 13751
• Main Authors: Yang, Shengna, Ding, Shiwen, Zhao, Chongyang, Huo, Siping, Yu, Fengjiao, Fang, Jun, Yang, Yang
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-08-2021; Springer Nature B.V
• Subjects: Annealing; Carbon nitride; Characterization and Evaluation of Materials; Charge transfer; Chemistry and Materials Science; Classical Mechanics; Clean energy; Crystallography and Scattering Methods; Electric contacts; Electric fields; Energy Materials; Heterojunctions; Hydrogen production; Ligands; Materials Science; Multilayers; Nanoclusters; Nanosheets; Noble metals; Photocatalysis; Photocatalysts; Polymer Sciences; Solar energy conversion; Solid Mechanics; Synthesis
• ISSN: 0022-2461; 1573-4803
• DOI: 10.1007/s10853-021-06184-7

In this paper, we report the synthesis of ligand-free Au nanoclusters (NCs)/g-C
3
N
4
ultra-thin nanosheets (NSs) composite via a facile wet-impregnation method with post-annealing. On the one hand, post-annealing was used for the exfoliation of multi-layered g-C
3
N
4
to obtain ultra-thin NSs; on the other hand, after Au
25
(Cys)
18
NCs were loaded, post-annealing was further adopted to remove the ligands to obtain clean surface on Au NCs. It is demonstrated that the loaded Au NCs were aggregating resistant by post-annealing. Constructing heterojunctions with appropriate inter-band structures between the ligand-free Au NCs and the ultra-thin g-C
3
N
4
NSs, along with the mono-distribution of the Au NCs and their intimate contact with g-C
3
N
4
NSs ensured the smooth interfacial charge transfer. As a result, the composite photocatalysts exhibited efficient visible-light-induced photocatalytic H
2
generation, mainly due to the local electric field enhancement induced by excitation of Au NCs under visible light and the improved charge separation in g-C
3
N
4
. This work provides a general strategy for the synthesis of noble metal NCs based composites with clean surface as the efficient photocatalysts for solar energy conversion.
Graphical Abstract
A stepwise post-annealing strategy is exploited to prepare g-C
3
N
4
ultra-thin nanosheets modified with highly dispersed ligand-free Au nanoclusters for efficient photocatalytic hydrogen production.