Considerable attention has been focused on the development of catalysts for the coupling reaction of carbon dioxide (CO 2 ) and epoxides due to the distinct advantages and importance of this reaction. To develop high-performance and easy-to-recycle catalyst is still a hot topic, especially for candidates with excellent activity under moderate conditions. A new heterogeneous catalyst, MIL-101-ImEtOH, is reported by post-synthesis modification, in which 2-(1-imidazol-1yl) ethanol (Im-EtOH) is immobilized on MIL-101(Cr). In the absence of solvent and co-catalyst, MIL-101-ImEtOH exhibits high activity for the cycloaddition of CO 2 and styrene oxide. A 95.6% yield is achieved under 0.5 MPa CO 2 pressure and 90 °C by utilization of 50 mg of catalyst for 3 h. Moreover, MIL-101-ImEtOH is easily separated from the catalytic system by simple filtration. To elucidate the influence of hydroxyl group and porous structure on catalysis, other two supported ionic liquids, MIL-101-EtIm and PS-ImEtOH, are prepared and used to catalyze the title reaction under the same conditions. The contribution of each active component is determined by density functional theory along with noncovalent interaction analysis.

Doping heteroatoms in carbon materials is a promising method to prepare the robust electrocatalysts for the carbon dioxide reduction reaction (CO2RR), which is beneficial for sustainable energy storage and environmental remediation. However, the obscure recognition of active sites is the obstacle for further development of high-efficiency electrocatalysts, especially for the N,P-codoped carbon materials. Herein, a series of N,P-codoped carbon materials (CNP) is prepared with different N and P contents to explore the relationship between the N/P configuration and the CO2RR activity. As compared with the N-doped carbon materials, the additional P doping is helpful to improve the activity. The optimum N,P-codoped carbon materials (CNP-900) achieve 80.8% CO Faradaic efficiency (FECO) at a mild overpotential of 0.44 V. On the basis of the X-ray photoelectron spectroscopy results, the suitable ratio between pyridinic N and graphitic N and the least P–N content are beneficial for CO2RR. The density functional theory calculations further illustrate that two elementary steps to form *COOH and *CO in CO2RR are determined by the graphitic N and pyridinic N configurations, respectively. The existence of the P–N configuration breaks the equilibrium between graphitic N and pyridinic N to suppress the activity.

Photocatalysis is a promising pathway to degrade pollutants in water. Although numerous photocatalysts have been developed to remove organic dyes in water, the degradation of antibiotics is still a perplexing problem due to their excellent stability. The hybrid photocatalyst upconversion nanoparticle (UCNP)/metal–organic framework (MOF) has been developed with the aim to utilize the full solar light. However, the low upconversion efficiency results in an unsatisfactory photocatalytic activity. A novel core–shell–shell UCNP, NaYF4:Yb/Tm@NaYF4:Yb@NaYF4 (Tm@Yb@Y), is synthesized to increase the upconversion efficiency. Both the active and inert shells are introduced in the UCNPs, which not only are favorable to weaken the surface quenching but also are helpful to prompt the energy transfer back. As a result, the UC emission intensity is greatly improved as compared with Tm or Tm@Yb. Then, Tm@Yb@Y is combined with NH2-MIL101­(Fe) (NMF) to fabricate the novel photocatalyst Tm@Yb@Y/NMF. It exhibits an excellent photocatalytic activity to degrade rhodamine B (RhB), levofloxacin (OFL), and tetracycline hydrochloride (TC). The contribution of near infrared (NIR) light and inert shell on the whole photocatalysis is considered. The possible photodegradation mechanism is proposed according to the photoelectrochemical measurements, free radical and hole trapping experiments, and pump power dependence of upconversion emission intensities. The outstanding performance of Tm@Yb@Y/NMF should be attributed to the synergistic effect including the wider light absorption range, increased UC emission intensity, and feasible electron–hole separation.

Developing metal-nitrogen-carbon (M-N-C)-based single-atom electrocatalysts for carbon dioxide reduction reaction (CO 2 RR) have captured widespread interest because of their outstanding activity and selectivity. Yet, the loss of nitrogen sources during the synthetic process hinders their further development. Herein, an effective strategy using 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM][BF 4 ]) as a liquid nitrogen source to construct a nickel single-atom electrocatalyst (Ni-SA) with well-defined Ni-N 4 sites on a carbon support (denoted as Ni-SA-BB/C) is reported. This is shown to deliver a carbon monoxide faradaic efficiency of >95% over a potential of −0.7 to −1.1 V (vs reversible hydrogen electrode) with excellent durability. Furthermore, the obtained Ni-SA-BB/C catalyst possesses higher nitrogen content than the Ni-SA catalyst prepared by conventional nitrogen sources. Importantly, only thimbleful Ni nanoparticles (Ni-NP) are contained in the large-scale-prepared Ni-SA-BB/C catalyst without acid leaching, and with only a slight decrease in the catalytic activity. Density functional theory calculations indicate a salient difference between Ni-SA and Ni-NP in the catalytic performance toward CO 2 RR. This work introduces a simple and amenable manufacturing strategy to large-scale fabrication of nickel single-atom electrocatalysts for CO 2 -to-CO conversion.

Lanthanide upconversion nanoparticles (UCNPs) have been extensively explored as biomarkers, energy transducers, and information carriers in wide-ranging applications in areas from healthcare and energy to information technology. In promoting the brightness and enriching the functionalities of UCNPs, core–shell structural engineering has been well-established as an important approach. Despite its importance, a strong limiting issue has been identified, namely, cation intermixing in the interfacial region of the synthesized core–shell nanoparticles. Currently, there still exists confusion regarding this destructive phenomenon and there is a lack of facile means to reach a delicate control of it. By means of a new set of experiments, we identify and provide in this work a comprehensive picture for the major physical mechanism of cation intermixing occurring in synthesis of core–shell UCNPs, i.e., partial or substantial core nanoparticle dissolution followed by epitaxial growth of the outer layer and ripening of the entire particle. Based on this picture, we provide an easy but effective approach to tackle this issue that enables us to produce UCNPs with highly boosted optical properties.