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Three-dimensional Ag nanoparticle/GNs (Ag/GNs) hybrids as highly efficient counter electrode (CE) materials for dye sensitized solar cells (DSSCs) is described, highlighting the Ag nanoparticles as zero-dimensional nanospacers inserting into GNs to lift the interspacing layer between individual GNs. It is demonstrated that, when the hybrids are used as CE materials for DSSCs, compared to their pure GNs, Ag/GNs hybrids without agglomerates have a significant improvement in their electrochemical properties such as high current density, narrow peak-to-peak separation (Epp) and low charge transfer resistance (RCT). The enhancement of electrochemical performance can be attributed to the increased electrode conductivity, an extended interlayer distance and the reduction of the restacking of graphene sheets due to the insertion of metallic Ag nanoparticles into GNs. The DSSC with this hybrid CE exhibited an energy conversion efficiency (η) of 7.72% with an open circuit voltage (VOC), short circuit photocurrent density (JSC), and fill factor (FF) of 732 mV, 14.67 mA cm(-2), and 71.8%, respectively.

A high‐efficiency counter electrode (CE) consisting of zero‐dimensional graphene quantum dots (GQDs)@graphene foam nanosheets (GFs) is proposed for dye‐sensitized solar cells (DSSCs). In the hybrid CE, the nanometer‐sized GQDs with more defect sites at the edges, provide outstanding electrocatalytic activity for the reduction of I3−. The high‐quality GFs with high electronic conductivity act as fast electron transportation channels for facilitating the charge injection between the GQDs and the fluorinated tin oxide (FTO) substrate. The DSSC with the optimized hybrid CE exhibits an energy conversion efficiency (η) of 9.59 % with an open‐circuit voltage (Voc), short‐circuit photocurrent density (Jsc), and fill factor (FF) of 0.75 V, 19.23 mA cm−2, and 66.5 %, respectively.