文摘
In this study, a new core鈥搒hell heterostructure of multiwalled carbon nanotube@reduced graphene oxide nanoribbon (MWCNT@rGONR) was prepared by modified microwave-assisted synthesis step and a chemical reduction. The core鈥搒hell heterostructure of MWCNT@rGONR was used as the catalytic film of the counter electrode (CE) of a dye-sensitized solar cell (DSSC). The chemical state and the degree of defects on the surface of MWCNT@rGONR were investigated by X-ray photoelectron spectroscopy (XPS) and Raman spectra, respectively. Transmission electron microscopy (TEM) image of the film of MWCNT@rGONR shows graphene sheet, covering on a MWCNT, indicating a core of the carbon nanotube and its shell of graphene. Photocurrent density鈥搗oltage characteristics of the DSSCs, using commercial graphene nanopowder (GNP), MWCNT, and MWCNT@rGONR as the CE materials were obtained at 100 mW cm鈥?. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were used to study the electrocatalytic abilities of the films of GNP, MWCNT, and MWCNT@rGONR. Owing to the excellent electrocatalytic ability of the MWCNT@rGONR for the reduction of triiodide ions (I3鈥?/sup>), a solar-to-electricity conversion efficiency (畏) of 6.91% was achieved for its DSSC, using our synthesized YD2-o-C8 porphyrin dye, while efficiencies of 4.48% and 5.93% were obtained for the DSSCs with the bare GNP and pristine MWCNT, respectively. The performance of the cell with the MWCNT@rGONR is comparable to that of the cell with a sputtered Pt (s-Pt) on its CE (7.26%).