To improve dispersibility of graphene for photocatalytic hydrogen evolution in water, hydrophilic reduced graphene GJ600 was simply prepared in situ through one-pot ring-opening reaction between graphene oxide precursor and industrial Jeffamine M-600 polyetheramine, which shows good dispersibility in an aqueous solution, and strong affinity toward metal ions. These features have been integrated to construct an enhanced photocatalytic H2 evolution system, in which eosin Y was employed as the photosensitizer, triethanolamine (TEOA) as the sacrificial electron donor, low cost Co2+ as the catalytic precursor. During irradiation by visible light, the aggregation of catalytic centre and graphene is greatly suppressed, and ∼3.78 times enhancement of photocatalytic H2evolution is achieved as compared with the system in the absence of graphene. By using HRTEM, XRD, XPS, ICP-AES, as well as spectroscopic and electrochemical approaches, an in situ formed core@shell composites of Cox/Co(TEOA)y(GJ600)z on the basal plane of the graphene sheets is verified as the real catalytic structure. This polymer-modified graphene not only help with the multi-electron transfer between photosensitizer and the catalytic metal centre but also facilitate the formation of this unique core@shell nanocomposites for efficient photocatalytic H2 evolution.
Journal of Photochemistry and Photobiology A: Chemistry
Available online 1 December 2015