Bei Long

Alkali-modified non-precious metal 3D-NiCo2O4 nanosheets for efficient formaldehyde oxidation at low temperature

Cost-effective catalysts for volatile organic compound (VOC) oxidation are critical to energy conversion and environmental protection. Herein, we developed new, low-cost and high-performance alkali-promoted 3D-NiCo2O4 nanosheet catalysts for HCHO oxidation at room temperature. Benefiting from the large surface area, high adsorption capacity and surface hydroxyls, the alkali-promoted 3D-NiCo2O4 nanosheet catalysts show substantially high catalytic activities for HCHO oxidation. The alkali-promoted 3D-NiCo2O4 nanosheets yield a remarkable HCHO conversion efficiency of 95.3% at room temperature, which is not achieved by any non-precious metal based catalysts at such low temperature. Additionally, the as-prepared alkali-promoted 3D-NiCo2O4 nanosheets retained excellent catalytic performance after 200 h, which can be applied to practical applications. This work provides a feasible approach to improve the efficiency of metal oxides for HCHO oxidation at low temperature.

Encapsulated Vanadium-Based Hybrids in Amorphous N-Doped Carbon Matrix as Anode Materials for Lithium-Ion Batteries

Recently, researchers have made significant advancement in employing transition metal compound hybrids as anode material for lithium-ion batteries and developing simple preparation of these hybrids. To this end, this study reports a facile and scalable method for fabricating a vanadium oxide-nitride composite encapsulated in amorphous carbon matrix by simply mixing ammonium metavanadate and melamine as anode materials for lithium-ion batteries. By tuning the annealing temperature of the mixture, different hybrids of vanadium oxide-nitride compounds are synthesized. The electrode material prepared at 700 °C, i.e., VM-700, exhibits excellent cyclic stability retaining 92% of its reversible capacity after 200 cycles at a current density of 0.5 A g-1 and attractive rate performance (220 mAh g-1 ) under the current density of up to 2 A g-1 . The outstanding electrochemical properties can be attributed to the synergistic effect from heterojunction form by the vanadium compound hybrids, the improved ability of the excellent conductive carbon for electron transfer, and restraining the expansion and aggregation of vanadium oxide-nitride in cycling. These interesting findings will provide a reference for the preparation of transition metal oxide and nitride composites as well.

Enhanced Photoelectrochemical Oxygen Evolution Reaction Ability of Iron-Derived Hematite Photoanode with Titanium Modification.

A facile fabrication route towards a titanium-modified hematite photoanode has been developed, and the photoelectrochemical properties of this anode have been evaluated. Compared to pristine hematite, the activity of the modified photoanode in this work delivered almost twofold higher photocurrent under Air Mass 1.5G illumination. Further research revealed that the enhanced performance of the hematite photoanode with a titanium-modified surface resulted from the dominant impact of heterojunction formation and suppressed surface recombination, supplemented by a slightly improved light-harnessing ability.