TY  - JOUR
AU  - Li, Guosheng
AU  - Hu, Zhuofeng
PY  - 2022
TI  - Bottom-up synthesis of semiconductive carbonaceous nanosheets on hematite photoanode for photoelectrochemical water splitting
JO  - Nano Research
SN  - 1998-0124
SP  - 627
EP  - 636
VL  - 15
IS  - 1
AB  - Coupling two-dimention carbon materials like graphene on photodelectrode can achieve high-efficiency photoelectrochemical cells. Bottom-up synthesis of carbon-based two-dimensional materials in green media from simple molecules is very attractive but remains a challenge. Carbohydrate is an ideal precursor for the synthesis but previous report requires pyrolysis at high temperature (> 700 ℃). Herein, starting with glucose, we develop a low temperature (210 ℃) synthesis of carbonaceous nanosheets in aqueous solution of glucose. With the aid of ethylenediamine and Fe3+/Fe2+/Co2+/Ni2+ ions, the nanosheets can grow on hematite nanorod array with very close contact. Importantly, a metallic region is formed at the interface due to atom distribution distortion, which can promote the charge transfer. The activity can be greatly enhanced by about 500% due to fast charge transfer. This is much better than that prepared by physically or chemically mixing graphene and hematite (< 200%). The enhancement is mainly due to the deformation area between the nanosheets and the hematite. The effective hole diffusion length increases from 2 to 8 nm and lifetime of charge carrier also increases, as confirmed by ultrafast transient absorption spectra. This method provides more opportunity for simple, mild and cost-effective fabrication of carbon-based two-dimensional by bottom-up method.
UR  - https://doi.org/10.1007/s12274-021-3529-2
DO  - 10.1007/s12274-021-3529-2