Distance-regulating surface plasmon catalyzed coupling reaction of p-nitrophenyl disulfide

Microscopic-Level Insights into Solvation Chemistry for Nonsolvating Diluents Enabling High-Voltage/Rate Aqueous Supercapacitors

Localized "water-in-salt" (LWIS) electrolytes are promising candidates for the next generation of high-voltage aqueous electrolytes with low viscosity/salt beyond high-salt electrolytes. An effective yet high-function diluent mainly determines the properties of LWIS electrolytes, being a key issue. Herein, the donor number of solvents is identified to serve as a descriptor of interaction intensity between solvents and salts to screen the organic diluents having few impacts on the solvation microenvironment and intrinsic properties of the original high-salt electrolyte, further leading to the construction of a novel low-viscosity electrolyte with a low dosage of the LiNO₃ salt and well-kept intrinsic Li⁺-NO₃^--H₂O clusters. Nonsolvating diluents, especially acetonitrile (AN) that has never been reported previously, are presented with the capability of constructing a LWIS electrolyte with nonflammability, electrode-philic features, lower viscosity, decreased salt dosage, and a greatly enhanced ion diffusion coefficient by about 280 times. This strongly relies on a huge difference of about 5000 times in coordination and solubility between AN and H₂O toward LiNO₃ (0.05 vs 25 mol kg_solvent^-1) and the moderate interaction between AN and H₂O. Multi-spectroscopic techniques and molecular dynamics simulations uncover the solvation chemistry at the microscopic level and the interplay among cations, anions, and H₂O without/with AN. The identified unique diluting and nonsolvating effects of AN reveal well-maintained cation-anion-H₂O clusters and enhanced intermolecular hydrogen bonding between AN and H₂O, further reinforcing the H₂O stability and expanding the voltage window up to 3.28 V. This is a breakthrough that is far beyond high-viscosity/salt electrolytes for high-voltage and high-rate aqueous supercapacitors.

Sulfite-triggered surface plasmon-catalyzed reduction of p-nitrothiophenol to p,p'-dimercaptoazobenzene

The conversion of p-aminothiophenol (PATP) or p-nitrothiophenol (PNTP) to p,p'-dimercaptoazobenzene (DMAB) has been used as model reactions to study plasmon-catalyzed reaction on nanoparticles. Herein, we report the conversion of PNTP to DMAB which is triggered by SO₃^2- ions on gold nanoparticles (AuNPs) for the first time. With the addition of SO₃^2-, the Raman peaks at 1139, 1392, 1437 cm^-1 appears, which indicates the formation of DMAB. The experiment results suggested that the synergistic effect of AuNPs and SO₃^2- promoted the conversion of PNTP to DMAB. Besides, the proposed catalysis system is high selectivity to SO₃^2- ions, which provides a new detection route to SO₃^2- ions in the future. More importantly, the possible reaction mechanism has been put forward which is helpful to understand the surface plasmon-assisted catalytic reduction of PNTP on the surface of SERS substrate.