Identifying suitable electrodes materials with desirable electrochemical properties is urgently needed for the next generation of renewable energy technologies. Here we report an ideal candidate material, Mo2C monolayer, with not only required large capacity but also high stability and mobility by means of first-principles calculations. After ensuring its dynamical and thermal stabilities, various low energy Li and Na adsorption sites are identified, and the electric conductivity of the host material is also maintained. The calculated minor diffusion barriers imply a high mobility and cycling ability of Mo2C. In addition, the Li-adsorbed Mo2C monolayer possesses a high theoretical capacity of 526 mAh·g(-1) and a low average electrode potential of 0.14 eV. Besides, we find that the relatively low capability of Na-adsorbed Mo2C (132 mAh·g(-1)) arises from the proposed competition mechanism. These results highlight the promise of Mo2C monolayer as an appealing anode material for both lithium-ion and sodium-ion batteries.

Effective CO2 capture and activation is a prerequisite step for highly efficient CO2 reduction. In this study, we reported a case of Cu(2+) in a porphyrin based MOF promoted enhanced photocatalytic CO2 conversion to methanol. Compared with the sample without Cu(2+), the methanol evolution rate was improved as high as 7 times. In situ FT-IR results suggested that CO2 chemical adsorption and activation over Cu(2+) played an important role in improving the conversion efficiency.

No abstract

The recent discovery of intrinsic ferromagnetism in two-dimensional (2D) van der Waals crystals down to the monolayer limit has sparked intense interest due to their potential applications in spintronics. Here, using first-principles calculations we predict that the 2D pristine MnX3 (X=F, Cl, Br, I) is a family of intrinsic Dirac half metals characterized by a band structure with an unusually large gap in one spin channel and a Dirac cone in the other with carrier mobilities comparable to those in graphene. We demonstrate that the MnX3 are dynamically and thermodynamically stable up to high temperatures, and exhibit large magnetic moments of about 4 µB per Mn 3+ ion, high Curie temperatures and large in-plane magnetic anisotropy energy. In addition, the gap opening induced by the spin-orbit coupling drives the lighter systems into the quantum anomalous Hall state. The combination of these unique properties renders this class of 2D ferromagnets a promising platform for high efficiency spintronic applications.

A visible-light-responsive bismuth-based metal-organic framework (Bi-mna) is demonstrated to show good photoelectric and photocatalytic properties. Combining experimental and theoretical results, a ligand-to-ligand charge transfer (LLCT) process is found to be responsible for the high performance, which gives rise to a longer lifetime of photogenerated charge carriers. Our results suggest that bismuth-based MOFs could be promising candidates for the development of efficient visible-light photocatalysts.