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Nano bowl-like Co–Co6Mo6C2 coated by N,P co-doped carbon (Co–Co6Mo6C2@NPC) is reported as an electrocatalyst for Zn–air batteries. Co–Co6Mo6C2@NPC only needs an overpotential of 210 mV at 10 mA cm−2 for the OER, and the half-wave potential for the ORR is 0.81 V. In addition, the Co–Co6Mo6C2@NPC based battery shows a large open-circuit voltage of 1.335 V and a maximum power density of 160.5 mW cm−2, as well as good stability. The improved catalytic performance can be ascribed to the co-existence of Co6Mo6C2 and Co species to improve the intrinsic catalytic activity, and the bowl-like nanostructure to facilitate the mass transfer. [ABSTRACT FROM AUTHOR]

One-dimensional MoO2–Co2Mo3O8@C nanorods were synthesized by using MoO3@ZIF-67 composites as a precursor for the first time, and it is found that the Co2Mo3O8 species and its composite have excellent OER activities. The MoO2–Co2Mo3O8@C nanorods present favorable electrocatalytic advantages toward OER in alkaline solution, requiring an overpotential of only 320 mV to deliver a current density of 10 mA cm−2. In addition, the catalyst also shows a small Tafel slope of 88 mV dec−1 and relatively good durability. The attractive OER performance can be attributed to the highly active Co2Mo3O8 and MoO2 species and the unique structure of the catalyst. This strategy can be extended to design and synthesize other novel and highly efficient molybdenum based ternary metal oxides as OER catalysts. [ABSTRACT FROM AUTHOR]

The presence of organic pollutants in the world is harmful to our existence and the environment. So efficient and energy-saving methods for the degradation of organic pollutants present in the environment are important and beneficial for humans and the environment. The use of emerging photocatalytic technology using semiconductor materials to degrade organic pollutants is an effective method with potential prospects for the future. In this work, quantum chemical calculations and classical molecular dynamics simulations are employed to investigate the performances and related reactivities of sulfide semiconductor materials for the photocatalytic degradation of several common organic compounds. The reactivity of the organics is studied using quantum chemical calculations. The adsorption behaviors of several types of organic compounds on the surfaces of sulfide semiconductors in the gas phase were investigated, then similar adsorption processes in the aqueous phase were studied, and then CdS semiconductors were used to explore the influence of different crystal planes on the adsorption behavior of organic matter. Based on adsorption energy calculations, the best adsorption performance for a specific type of organic matter on a sulfide semiconductor was explored, together with an adsorption comparison in the gas and water phases. The results of this study may provide theoretical guidance for sulfide semiconductor photocatalysis technology and give ideas for subsequent experiments. [ABSTRACT FROM AUTHOR]

Birefringent materials are vital materials to modulate the polarization of light, and play a key role in plorization devices such as linear optical devices, optical communication devices, and fiber optic sensors. It is still a challenge to design excellent birefringent materials. Herein, we report an organic–inorganic hybrid oxalate birefringent material, (CN4H7)SbC2O4F2(H2O)0.5, by introducing organic delocalized π-conjugated [CN4H7]+ and [C2O4]2− groups, and stereochemical active inorganic SbO4F2 polyhedra. (CN4H7)SbC2O4F2(H2O)0.5 exhibits a large birefringence (Δn = 0.126@546 nm) that is almost equal to that of the well-known birefringent material α-BaB2O4. Theoretical calculations reveal that the distinguished birefringence should stem from the synergistic arrangement of π-conjugated [CN4H7]+ and [C2O4]2− planar groups, and highly distorted SbO4F2 polyhedra with a stereochemically active lone pair. The synergistic effect of π-conjugated systems and the lone pair electrons greatly boosts the birefringence, which is helpful for the development of high-performance birefringent materials. [ABSTRACT FROM AUTHOR]