Development of visible-light photocatalytic materials is an ultimate goal for solar-driven CO2 conversion. Au nanoclusters (NCs) may potentially serve as components for harvesting visible light but can hardly perform solar-driven CO2 reduction due to the lack of catalytic sites. Herein, we report an effective strategy for turning Au nanoclusters catalytically active for visible-light CO2 reduction, in which metal cations (Fe2+, Co2+, Ni2+, and Cu2+) are grafted to the Au NCs using l-cysteine as a bridging ligand. The metal–S bonding bridge facilitates the electron transfer from Au NCs to metal cations so that the grafted metal cations can receive photoinduced electrons and work as catalytic sites for CO2 reduction. The varied d-band centers and binding energies with CO2 for different metal cations allow tuning electron transfer efficiency and CO2 activation energy. Furthermore, the photostability of Au NCs-based catalyst can be significantly enhanced through the encapsulation with metal–organic frameworks. This work opens a new door for the photocatalyst design based on metal clusters and sheds light on the surface engineering of metal clusters toward specific applications.

We synthesized a series of FeCl 3 /[C 4 mim]Cl (iron(III) chloride with 1-butyl-3-methylimidazolium chloride) ionic liquids. The temperature dependence of the Raman spectra of the FeCl 3 /[C 4 mim]Cl ionic liquids was measured for the first time to analyze their ionic species. In addition, the infrared spectra, thermodynamic properties, and freeze-fracture transmission electron microscopy were combined together with the Raman spectra to reveal the microscopic information of the

The density, viscosity, conductivity, and heat capacity of 1-hexyl-3-methylimidazolium hexafluorophosphate ([C 6 mim][PF 6 ]) and 1-hexyl-3-methylimidazolium tris(perfluoroalkyl)trifluorophosphate ([C 6 mim][(C 2 F 5 ) 3 PF 3 ]) were measured in the (293.15 to 343.15) K range. According to these experimental and estimated results, the coefficients of thermal expansion and conductivity apparently increase from [C 6 mim][PF 6 ] to [C 6 mim][(C 2 F 5 ) 3 PF 3 ], while the crystal energy, the temperature dependence of the heat capacity, and viscosity greatly decrease from [C 6 mim][PF 6 ] to [C 6 mim][(C 2 F 5 ) 3 PF 3 ] in the examined temperature range. These comparisons were combined to assess the effect of the replacement of three F atoms of the hexafluorophosphate anion by three hydrophobic C 2 F 5 -groups on the physicochemical properties of [C 6 mim][PF 6 ] and [C 6 mim][(C 2 F 5 ) 3 PF 3 ].

The simple equations for predictions of the density, viscosity, and conductivity of mixed electrolyte solutions were extended to the related properties of mixed ionic liquid solutions. The densities, viscosities, and conductivities were measured for the ternary solutions [C 4 H 2 O and their binary subsystems [C 4 mim]Cl þ H 2 O, [C 4 mim]Br þ H 2 O, [C 6 mim]Cl þ H 2 O, and [C 6 mim]Br þ H 2 O at (293.15, 298.15, and 308.15) K, respectively. The results were used to test the predictability of the extended equations. The comparison results show that these simple equations can be used to predict the density, viscosity, and conductivity of the mixed ionic liquid solutions from the properties of their binary subsystems of equal ionic strength.

Densities were measured for the ternary systems Y(NO 3 ) 3 + Ce(NO 3 ) 3 + H 2 O, Y(NO 3 ) 3 + Nd(NO 3 ) 3 + H 2 O, and Ce(NO 3 ) 3 + Nd(NO 3 ) 3 + H 2 O and their binary subsystems at (293.15, 298.15, and 308.15) K. The results were used to test the applicability of simple equations for the density of the mixed solutions. The predictions are in good agreement with measured values, implying that the densities of the examined electrolyte solutions can be well predicted from those of their constituent binary solutions by the simple equations.