摘要
Carbon nitride-based photocatalysts hold an enormous potential in producing hydrogen.A strategy to simultaneously create isotype heterojunctions and active sites in highly-crystallized carbon nitride is anticipated to significantly boost the photocatalytic activity,but is yet to be realized.Herein,we find that cobalt salt added in the ionothermal synthesis can promote the phase transition of heptazine-based crystalline carbon nitride(CCN)to triazine-based poly(triazine imide)(PTI),rendering the creation of singleatom cobalt coordinated isotype CCN/PTI heterojunction.Co-CCN/PTI exhibits an appreciable apparent quantum yield of 20.88%at 425 nm for photocatalytic hydrogen production with a rate achieving3538μmol h^(-1)g^(-1)(λ>420 nm),which is 4.8 times that of CCN and 27.6 times that of PTI.The high photocatalytic activity is attributed to the Type II isotype highly-crystallized CCN/PTI heterojunction for promoting charge carrier migration,and the single-atom Co sites for accelerating surface oxidation reaction.
石墨相氮化碳类光催化剂在光催化制氢应用中展示了巨大潜力.本文提出了一种同时构建高结晶氮化碳同型异质结并构筑单原子活性位点的策略.研究发现在离子热合成中加入钻盐,能促进庚嗪基结晶氮化碳(CCN)向三嗪基结晶氮化碳(PTI)的相变,同时,钴盐可作为单原子钴活性位点的金属源.该Co-CCN/PTI光催化剂在425 nm处达到了20.88%的表观量子效率,在可见光波段(λ>420 nm)达到了3538 Nmol h^(-1)g^(-1)的制氢速率,该速率分别比CCN高4.8倍,比PTI高27.6倍.分析结果表明,CCN/PTI之问的TypeⅡ同型异质结可有效促进电荷分离,Co单原子活性位点可加速表面氧化反应,这两方面因素同时促进光催化制氢性能的提高.
作者
Shaohua Shen
Jie Chen
Yiqing Wang
Chung-Li Dong
Fanqi Meng
Qinghua Zhang
Yiliang Huangfu
Zhi Lin
Yu-Cheng Huang
Yanrui Li
Mingtao Li
Lin Gu
沈少华;陈杰;王亦清;董崇礼;孟繁琦;张庆华;皇甫亦亮;林治;黄裕呈;李燕瑞;李明涛;谷林(International Research Center for Renewable Energy,State Key Laboratory of Multiphase Flow in Power Engineering,Xi’an Jiaotong University,Xi’an 710049,China;School of Chemical Engineering and Technology,Xi’an Jiaotong University,Xi’an 710049,China;Department of Physics,Tamkang University,New Taipei City 25137,Taiwan,China;Beijing National Laboratory for Condensed Matter Physics,Institute of Physics,Chinese Academy of Sciences,Beijing 100190,China)
基金
supported by the National Key Research and Development Program of China(2018YFB1502003)
the National Natural Science Foundation of China(51961165103)
supported by the National Program for Support of Top-notch Young Professionals and‘‘The Youth Innovation Team of Shaanxi Universities”。
作者简介
Corresponding author:Shaohua Shen is currently a full professor at Xi’an Jiaotong University,China.He obtained his Bachelor degree in Applied Chemistry in 2004 and Ph.D.degree in Thermal Engineering in 2010 from Xi’an Jiaotong University.During 2008–2009 and 2011–2012,he worked as a guest researcher at Lawrence Berkeley National Laboratory and a postdoctoral researcher at the University of California at Berkeley.His research interest includes synthesis of nanomaterials and development of devices for photocatalytic and photoelectrochemical solar energy conversion.E-mail address:shshen_xjtu@mail.xjtu.edu.cn(S.Shen).
