Mw 40000

We prepare TMD MMLs following a similar procedure as previously reported^{19 (link)}. We first deposit a 150 nm gold film on Si wafer by e-beam evaporation (0.05 nm/s), then spin-coat the gold film by polyvinylpyrrolidone (PVP) solution (Sigma Aldrich, mw 40000, 10% wt in ethanol/acetonitrile wt 1/1) at 1500 rpm for 2 min, with the acceleration of 500 rpm/s, and anneal at 150 °C for 2 min. A single-sided heat release tape is cut into small pieces (~1 $\times$ 1 cm² square) and stuck onto the PVP/gold surface to peel off the gold film from the Si wafer to form a gold tape, which is then gently pressed onto a TMD single crystal (purchased from HQ Graphene) to exfoliate a monolayer. The TMD monolayer on the gold tape is then transferred onto a desired substrate. In this work, substrates used include SiO₂(285 nm)/Si with and without 1-dedaconal on top, fused silica, and silicon nitride substrates. We then heat the substrate with everything on top using a hot plate at 135 °C for 3 min to remove the heat release tape, followed by water soaking for 4 h to remove the PVP layer on gold. Finally, the gold layer is removed by gold etchant (2.5 g I₂ and 10 g KI in 100 mL deionized water), and the TMD monolayer on substrate is washed by water and isopropanol, then dried by a nitrogen gun.

We prepare TMD MMLs following a similar procedure as previously reported^{19 (link)}. We first deposit a 150 nm gold film on Si wafer by e-beam evaporation (0.05 nm/s), then spin-coat the gold film by polyvinylpyrrolidone (PVP) solution (Sigma Aldrich, mw 40000, 10% wt in ethanol/acetonitrile wt 1/1) at 1500 rpm for 2 min, with the acceleration of 500 rpm/s, and anneal at 150 °C for 2 min. A single-sided heat release tape is cut into small pieces (~1 $\times$ 1 cm² square) and stuck onto the PVP/gold surface to peel off the gold film from the Si wafer to form a gold tape, which is then gently pressed onto a TMD single crystal (purchased from HQ Graphene) to exfoliate a monolayer. The TMD monolayer on the gold tape is then transferred onto a desired substrate. In this work, substrates used include SiO₂(285 nm)/Si with and without 1-dedaconal on top, fused silica, and silicon nitride substrates. We then heat the substrate with everything on top using a hot plate at 135 °C for 3 min to remove the heat release tape, followed by water soaking for 4 h to remove the PVP layer on gold. Finally, the gold layer is removed by gold etchant (2.5 g I₂ and 10 g KI in 100 mL deionized water), and the TMD monolayer on substrate is washed by water and isopropanol, then dried by a nitrogen gun.

One-component model solutions of compositions similar to that of real leach solutions were prepared by dissolving the required amounts of PtCl₄ (94%, Sigma Aldrich), PdCl₂ (99.9%, Sigma Aldrich), or RhCl₃ (99.9%, Sigma Aldrich) in acidic medium. Polyvinylpyrrolidone (PVP) (Mw – 40,000, Sigma Aldrich) and sodium borohydride (NaBH₄) (> 99.0%, Acros) were used as a stabilizing agent and a reducer, respectively. A portion of 3 M HNO₃ (60%, Acros) was used for Pt, 0.5 M HCl (pure p.a., Chempur, Poland) for Pd, and for Rh the acid mixture was twice diluted with HCl/H₂SO₄/H₂O₂ (HCl and H₂SO₄ – pure p.a., Chempur, Poland, H₂O₂ – ACS reagent, Avantor, Poland). A 5 M NaOH solution (pure p.a., POCH, Poland) was used to adjust the pH during precipitation of Pd and Rh. Commercial TiO₂ (Aeroxide® TiO₂ P25) was used as a support for the preparation of supported PGM catalysts. Stripping solutions obtained according to the method previously reported for the recovery of precious metals from SACs were used as real PGM precursor solutions (Wiecka et al. 2022 (link)).