Bridging effect of Co heteroatom between g-C3N4 and Pt NPs for enhanced photocatalytic hydrogen evolution

• Published in: Chemical engineering journal (Lausanne, Switzerland : 1996) Vol. 394; p. 124964
• Main Authors: Cai, Hairui, Wang, Bin, Xiong, Laifei, Yang, Guang, Yuan, Longyun, Bi, Jinglei, Yu, Xiaojing, Zhang, Xiaojing, Yang, Sen, Yang, Shengchun
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15.08.2020
• Subjects: Bridging effect; Co atom bridge; g-C3N4; Photocatalytic hydrogen evolution; Superficial potential trap; g-C3N4; Co atom bridge; Bridging effect; Photocatalytic hydrogen evolution; Superficial potential trap
• ISSN: 1385-8947; 1873-3212
• DOI: 10.1016/j.cej.2020.124964

•Superficial potential trap is formed near Co atom in g-C3N4(Co).•Co atom act as a bridge to connect g-C3N4 and Pt NPs.•The bridging effect of Co atom can rapidly transfer the photo-induced electrons.•The water molecule is more easily dissociated by Co atom bridge.•The photocatalytic activity of g-C3N4(Co)-Pt is 145.8 times that of pristine g-C3N4. To achieve a highly efficient charge transfer and separation for photocatalysis, we propose a bridging effect to construct a direct charge transfer path in g-C3N4via introducing Co atoms into the nitride pores of g-C3N4 to trigger a superficial potential trap. By utilizing such superficial potential trap, the Co atom can bridge the ultrafine Pt NPs and g-C3N4 as catalyst for hydrogen evolution reaction. The bridging effect of Co heteroatom in g-C3N4(Co)/Pt can rapidly transfer the photo-generated electrons on g-C3N4 to Pt NP surface, thus significantly improving the charge separation efficiency. Moreover, the water molecule is more easily dissociated by Co atom bridge, enabling its kinetics favorable for photocatalytic hydrogen reaction. As a consequence, the photocatalytic H2 evolution rate of g-C3N4(Co)/Pt reaches 7.145 mmol g−1 h−1 with an excellent apparent quantum efficiency of 19.0% at 420 nm, which is 145.8 times than that of pristine g-C3N4.