TY - JOUR
T1 - Cobaloxime coenzyme catalyzing artificial photosynthesis for hydrogen generation over CdS nanocrystals
AU - Niu, Fujun
AU - Shen, Shaohua
AU - Zhang, Ning
AU - Chen, Jie
AU - Guo, Liejin
N1 - Publisher Copyright:
© 2016 Elsevier B.V.
PY - 2016/12/15
Y1 - 2016/12/15
N2 - Inspired by the natural photosynthesis, artificial photosynthesis (AP) systems comprised of light harvesters and redox catalysts have been widely investigated for photocatalytic H2 generation. Here we report an artificial photosynthesis system composed of CdS nanocrystals as photosensitizer, cobaloxime coenzyme (Co(dmgBF2)2(H2O)2, Co) as catalyst, and lactic acid (LA) as electron donor for H2 generation in a fully aqueous solution. This CdS/Co/LA system exhibits exceptional high photocatalytic activity under visible light, with initial H2 generation rate increased by 4000% compared to CdS/LA, which is even 700% as high as that of CdS/Pt/LA. The excellent photocatalytic performance of CdS/Co/LA should be attributed to the efficient electron transfer from CdS to Co, leading to the reduced charge recombination, as well as the positively shifted Fermi level of CdS, decreasing the overpotential for H2 generation. Moreover, the electron-coupling-electron-coupling (ECEC) mechanism, involving with the reduction of Co coenzyme followed by protonation and then reduction again, was supposed to produce the Co(II)-H intermediate active for catalyzing H2 evolution from aqueous solution.
AB - Inspired by the natural photosynthesis, artificial photosynthesis (AP) systems comprised of light harvesters and redox catalysts have been widely investigated for photocatalytic H2 generation. Here we report an artificial photosynthesis system composed of CdS nanocrystals as photosensitizer, cobaloxime coenzyme (Co(dmgBF2)2(H2O)2, Co) as catalyst, and lactic acid (LA) as electron donor for H2 generation in a fully aqueous solution. This CdS/Co/LA system exhibits exceptional high photocatalytic activity under visible light, with initial H2 generation rate increased by 4000% compared to CdS/LA, which is even 700% as high as that of CdS/Pt/LA. The excellent photocatalytic performance of CdS/Co/LA should be attributed to the efficient electron transfer from CdS to Co, leading to the reduced charge recombination, as well as the positively shifted Fermi level of CdS, decreasing the overpotential for H2 generation. Moreover, the electron-coupling-electron-coupling (ECEC) mechanism, involving with the reduction of Co coenzyme followed by protonation and then reduction again, was supposed to produce the Co(II)-H intermediate active for catalyzing H2 evolution from aqueous solution.
KW - Artificial photosynthesis
KW - Cobaloxime coenzyme
KW - Hydrogen generation
UR - https://www.scopus.com/pages/publications/84976336481
U2 - 10.1016/j.apcatb.2016.06.029
DO - 10.1016/j.apcatb.2016.06.029
M3 - 文章
AN - SCOPUS:84976336481
SN - 0926-3373
VL - 199
SP - 134
EP - 141
JO - Applied Catalysis B: Environmental
JF - Applied Catalysis B: Environmental
ER -