Hierarchically porous carbon-coated ZnO quantum dots (QDs) (~3.5 nm) were synthesized by a one-step controlled pyrolysis of the metal-organic framework IRMOF-1. We have demonstrated a scalable and facile synthesis of carbon-coated ZnO QDs without agglomeration by structural reorganization. This unique microstructure exhibits outstanding electrochemical performance (capacity, cyclability, and rate capability) when evaluated as an anode material for lithium ion batteries.

Hummers method has been used for 50 years to prepare graphene oxide (GO) by oxidizing graphite using Mn2O7. In this work, a new angle on Hummers method is described. The oxidation procedure before the addition of water, which has been respected as the main oxidation step of Hummers method, is named step I oxidation, and the widely ignored further oxidation step after the addition of water is named step II oxidation. The chemical and structural evolutions during step II oxidation was demonstrated for the first time using various techniques including atomic force microscopy (AFM), dynamic light scattering (DLS), X-ray photoelectron spectroscopy (XPS), ultraviolet–visible light (UV–vis) spectroscopy, Fourier-transform infrared spectroscopy (FT-IR), 13C nuclear magnetic resonance (NMR), and zeta-potentiometry. Step II oxidation influences the size of GO, defects within the layers, and functional groups on the surface, which affect the thermal stability of GO and the properties of resultant thermally reduced GO. This work provides new chemical insights into GO and guidelines for preparation of tailor-fitted GO.

The methanol-to-olefins (MTO) process produces high value-added light olefins from non-petroleum sources. Acidic zeotypes containing cages bounded by 8-ring (small pore) windows can effectively catalyze the MTO reaction, since their cages can accommodate the necessary aromatic intermediates that produce the light olefin products that escape. While progress on the mechanisms of the MTO reaction continues, zeotype structure-reaction property relationships have yet to be elucidated. Here, we report MTO reaction results from various small pore, cage-containing SAPO/MAPOs and zeolites under the same reaction conditions. The MTO behaviors of microporous materials having the following topologies are investigated: LEV, ERI, CHA, AFX, SFW, AEI, DDR, RTH, ITE, SAV, LTA, RHO, KFI and UFI. The previous observation that light olefin product distributions from a series of small pore, cage-containing zeolites can be classified into four structural categories is further supported by the results shown here from zeolite structures not investigated in the previous study and SAPO and MAPO materials with isostructural frameworks to all the zeolites. Additionally, these data reveal that light olefin product distributions are essentially the same over a given topology independent of framework composition. In order to develop a structure-property relationship between the framework topology and the MTO light olefin product distribution, the concept of the cage-defining ring size is introduced. The cage-defining ring size is defined as the minimum number of tetrahedral atoms of the ring encircling the center of the framework cages in the molecular sieve topology. It is shown that the cage-defining ring size correlates with MTO light olefin product distribution.

No abstract

Figure S1. Comparison between the crystal structures of CIT-13 and IM-12. (A) CIT-13 viewed along the [001] direction showing the 14-ring pore, and (B) along the [010 direction showing the 10-ring pore. (C) IM-12 viewed along the [001] direction showing the 14-ring pore, and (D) along the [010] direction showing the 12-ring pore.