Edge-Active Enriched MoS₂ Porous Nanosheets as Efficient Pt-Free Catalysts toward the Triiodide Reduction Reaction

Abstract

Developing high-efficiency counter electrode (CE) catalysts for the triiodide (I 3 − ) reduction reaction (IRR) is of great significance for the development of cost-effective dye-sensitized solar cells (DSSCs). From the perspective of further enhancing the catalytic activity of CE catalysts by exposing more active sites, edge-active enriched MoS 2 porous nanosheets are elaborately constructed using the as-prepared one-dimensional MoO 3 rods and poly-(vinylpyrrolidone) (PVP) as a template-directing agent and surfactant based on the dissolution−recrystallization strategy (MoS 2 -P), respectively, while the MoS 2 quasi-particles (MoS 2 -C) and irregular MoS 2 aggregations are also synthesized using cetyltrimethyl ammonium bromide (CTAB) as a surfactant and commercial MoO 3 powder as a molybdenum source under similar reaction processes. Benefiting from the high specific surface area, exposure of edge active sites, and effective ion diffusion-favored structure, MoS 2 -P delivers good photovoltaic performance (PCE = 8.16%, V oc = 0.782 V, J sc = 16.77 mA/cm 2 , FF = 0.62) when used as a CE catalyst for DSSCs, superior to that of MoS 2 -C (PCE = 6.87%, V oc = 0.741 V, J sc = 15.91 mA/cm 2 , FF = 0.58), which is comparable with that of the Pt-based device (PCE = 8.33%, V oc = 0.775 V, J sc = 16.85 mA/cm 2 , FF = 0.64). A series of electrochemical results further reveal that the obtained MoS 2 -P has good catalytic activity for the IRR and electrochemical stability in iodine-based electrolytes. Hence, our work may provide a promising catalyst for the energy conversion field.

Graphene-Supported Small-Sized FeSe2 Nanoparticles As Efficient Counter Electrode Catalysts for Dye-Sensitized Solar Cells

“…by combining the collected electrons from the external circuit and regenerating the oxidized N719 dye molecules simultaneously. − For a long time, the noble metal platinum (Pt) has been regarded as the most representative CE catalyst for iodine-based DSSCs owing to its outstanding catalytic property . However, its non-negligible disadvantages, including its expensive price and easy corrosion by iodine-based electrolytes, hampered the large-scale development of DSSCs based on Pt CEs. , Currently, extensive efforts are being made to develop effective CE catalysts with earth-abundant elements, excellent catalytic activity for the I 3 – reduction reaction (IRR), high charge-transfer capability, and long-term electrochemical stability to deliver satisfactory photovoltaic performance of DSSCs. − For this, attractive CE catalysts such as carbon materials, − alloys, , transition metal chalcogenides, − and their composites − have been considered as potential candidates to promote the practical application of DSSCs because of their tunable catalytic activity for IRR, high inertness against corrosion by the electrolyte, good electrochemical stability, and impressive photovoltaic performance.…”