Graphene–NiO nanohybrid prepared by dry plasma reduction as a low-cost counter electrode material for dye-sensitized solar cells

Abstract

NiO nanoparticles (NPs) were hybridized on the surface of reduced graphene oxide (RGO) by dry plasma reduction (DPR) at atmospheric pressure without any toxic chemicals and at a low temperature. NiO-NPs of 0.5-3 nm size, with a typical size of 1.5 nm, were uniformly hybridized on the surface of RGO. An XPS analysis and the Raman spectra also revealed the repair of some structural damage on the basal plane of the graphene. The material when applied to the counter electrode (CE) of dye-sensitized solar cells (DSCs) exhibited a power conversion efficiency of 7.42% (± 0.10%), which is comparable to a conventional Pt-sputtered CE (8.18% (± 0.08%)). This material outperformed CEs produced using NiO-NPs (1.53% (± 0.15%)), GO (4.48% (± 0.12%)) and RGO (5.18% (± 0.11)) due to its high electrochemical catalytic activity and high conductivity. The charge transfer resistance for NiO-NP-RGO was as low as 1.93 Ω cm(2), while those of a NiO-NP-immobilized electrode and a GO-coated electrode were 44.39 Ω cm(2) and 12.19 Ω cm(2), respectively, due to a synergistic effect.

Sandwich-like octahedral cobalt disulfide/reduced graphene oxide as an efficient Pt-free electrocatalyst for high-performance dye-sensitized solar cells

“…7a) to fit the spectra of graphene-based electrodes [48] using the Z-view software, while traditional Randies equivalent circuit (Fig. S9a) where j 2 = -1, ω is the frequency, CPE dl -T and CPE dl -P are the frequency-independent parameters of the CPE dl [49]. CPE dl -T is related to the active surface area, while CPE dl -P is corresponding to the porosity of CE.…”

Graphene nanosheets@ZnO nanorods as three-dimensional high efficient counter electrodes for dye sensitized solar cells

“…To exploit this unique feature, the aggregation of GNs has to be minimized or ideally prevented. Recently, Ho-Suk Choi et al 2 and Tingli Ma et al 21 explored hybrid graphene-NiO and transition metal oxides (MoO 2 and Nb 2 O 5 ) as DSSCs CEs and obtained energy conversion efficiencies of 7.42% and 4.84%, respectively. These indicate that transition metal oxides would be promising materials as CEs for DSSCs.…”

“…The CE plays a key role in regulating the DSSC performance by catalyzing the reduction of the iodide-triiodide redox species used as a mediator to regenerate the sensitizer after electron injection. [1][2][3][4] Therefore, the ideal CE material should possess a low sheet resistance, high reduction catalytic activity, good chemical stability, and low production cost. 5,6 Because of its excellent electrocatalytic activity for the iodine reduction, high conductivity and good chemical stability, platinum (Pt) has been widely used as a CE in DSSCs.…”

Recent Progress on the Synthesis of Graphene-Based Nanostructures as Counter Electrodes in DSSCs Based on Iodine/Iodide Electrolytes

“…This method was adopted for the synthesis of graphene/NiO hybrids as potential counter electrodes in DSSCs [20]. A solution of nickel chloride was dropped onto a graphene oxide film, followed by the evaporation of the solvent.…”