Ionic liquid-derived PtNi alloy nanoparticles encapsulated in multiwalled carbon nanotubes as the versatile and high-performance counter electrodes for dye-sensitized and perovskite solar cells

In this study, a synthesis route for fabricating Pt x Ni y alloy nanoparticles on multiwalled carbon nanotubes (Pt x Ni y /MWCNTs) support through a one-pot pyrolysis method by the use of bis(trifluoromethylsulfonyl) imide ([Tf 2 N]) ionic liquid (IL) containing nickel precursor (Ni[Tf 2 N] 2 ) was outlined. Using Ni[Tf 2 N] 2 as a nickel precursor, the enhancement of adhesion of the PtNi nanoparticles on the MWCNT substrate was achieved. Eventually, a dye-sensitized solar cell (DSSC) incorporating the PtNi/MWCNTs displays a power conversion efficiency (PCE) of 9.79% with outstanding photovoltaic performance parameters including J sc = 21.1 mA·cm −2 , V oc = 0.73 V, and FF = 64%, which is superior to a commercial Pt CE (7.84%). Moving forward, the PtNi/MWCNT CE prepared by the Ni[Tf 2 N] 2 was further explored the versatile deployment of perovskite solar cells (PSCs). The obtained results show that the fabricated PSC with a PtNi/MWCNT CE achieves a champion PCE of 15.3%, significantly higher than the control device with a MWCNT CE (12.0%). The PtNi/MWCNT composite prepared by the Ni[Tf 2 N] 2 offers the practical and cost-effective substitute for Pt and gold (Au) or silver (Ag) in high-performance DSSCs and PSCs, respectively. The above results provide notable breakthrough of advancements in photovoltaic (PV) technology and present forward-looking insights into future trends, noted for its high efficiency and elegant design.