Abstract can be found here: https://doi.org/10.1021/acscatal.8b0196

Achilleos, DS

Durrant, JR

Fang, X

Godin, R

Jeay-Bizot, C

Kasap, H

Reisner, E

English

Apollo (Cambridge)

Interfacial Engineering of a Carbon Nitride-Graphene Oxide-Molecular Ni Catalyst Hybrid for Enhanced Photocatalytic Activity

Carbon nitrides (CNx) are a promising
class of photocatalyst for fuel and chemical synthesis as they are
nontoxic and readily synthesized at a low cost. This study reports
the enhanced photocatalytic activity for simultaneous alcohol oxidation
and proton reduction when graphene oxide (GO) or reduced graphene
oxide (RGO) is employed as an interlayer between a cyanamide-functionalized
melon-type carbon nitride (NCNCNx) and a phosphonated Ni-bis­(diphosphine)
H2-evolution catalyst (NiP). Introduction
of the GO/RGO enhanced the activity three times, reaching a specific
activity of 4655 ± 448 μmol H2 (g NCNCNx)−1 h–1 with a NiP-based turnover frequency of 116 ± 3
h–1. Mechanistic studies into this closed photoredox
system revealed that the rate of electron extraction from NCNCNx is rate limiting. GO/RGO is commonly employed to improve the
electron transfer dynamics on nanosecond time scales, but time-resolved
photoluminescence and transient absorption spectroscopy reveal that
these properties are not significantly affected in our NCNCNx-GO hybrid on fast time scales (<0.1 s). However,
long-lived “trapped-electrons” generated upon photoexcitation
of NCNCNx in the presence of organic substrates are shown by
photoinduced absorption spectroscopy to be quenched faster with GO/RGO,
supporting that GO/RGO improves electron transfer from NCNCNx to NiP on time scales >0.1 s. The absorption
profile of NiP in the presence of different GO loadings
reveals that GO acts as a conductive interfacial “binder”
between NiP and NCNCNx. The enhancement in activity
therefore does not primarily arise from changes in the photophysics
of the NCNCNx, but rather from GO/RGO enabling better electronic
communication between NCNCNx and NiP

Hatice Kasap (2878976)

Robert Godin (1361646)

Chiara Jeay-Bizot (5474579)

Demetra S. Achilleos (2267422)

Xin Fang (134979)

James R. Durrant (1268991)

Erwin Reisner (1298334)

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Interfacial Engineering of a Carbon Nitride–Graphene
Oxide–Molecular Ni Catalyst Hybrid for Enhanced Photocatalytic
Activity

https://www.repository.cam.ac.uk/bitstream/handle/1810/282814/CNx_GO_main_accepted_uploaded.pdf?sequence=1&isAllowed=y

Interfacial Engineering of a Carbon Nitride-Graphene Oxide-Molecular Ni Catalyst Hybrid for Enhanced Photocatalytic Activity

Abstract

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