Weiwei Chen

Abstract As electron transfer to CO 2 is generally considered to be the critical step during the activation of CO 2 , it is important to develop approaches to engineer the electronic properties of catalysts to improve their performance in CO 2 electrochemical reduction. Herein, we developed an efficient strategy to facilitate CO 2 activation by introducing oxygen vacancies into electrocatalysts with electronic‐rich surface. ZnO nanosheets rich in oxygen vacancies exhibited a current density of −16.1 mA cm −2 with a Faradaic efficiency of 83 % for CO production. Based on density functional theory (DFT) calculations, the introduction of oxygen vacancies increased the charge density of ZnO around the valence band maximum, resulting in the enhanced activation of CO 2 . Mechanistic studies further revealed that the enhancement of CO production by introducing oxygen vacancies into ZnO nanosheets originated from the increased binding strength of CO 2 and the eased CO 2 activation.

Abstract Hydrogen produced from neutral seawater electrolysis faces many challenges including high energy consumption, the corrosion/side reactions caused by Cl - , and the blockage of active sites by Ca 2+ /Mg 2+ precipitates. Herein, we design a pH-asymmetric electrolyzer with a Na + exchange membrane for direct seawater electrolysis, which can simultaneously prevent Cl - corrosion and Ca 2+ /Mg 2+ precipitation and harvest the chemical potentials between the different electrolytes to reduce the required voltage. In-situ Raman spectroscopy and density functional theory calculations reveal that water dissociation can be promoted with a catalyst based on atomically dispersed Pt anchored to Ni-Fe-P nanowires with a reduced energy barrier (by 0.26 eV), thus accelerating the hydrogen evolution kinetics in seawater. Consequently, the asymmetric electrolyzer exhibits current densities of 10 mA cm −2 and 100 mA cm −2 at voltages of 1.31 V and 1.46 V, respectively. It can also reach 400 mA cm −2 at a low voltage of 1.66 V at 80 °C, corresponding to the electricity cost of US$1.36 per kg of H 2 ($0.031/kW h for the electricity bill), lower than the United States Department of Energy 2025 target (US$1.4 per kg of H 2 ).

Abstract As electron transfer to CO 2 is generally considered to be the critical step during the activation of CO 2 , it is important to develop approaches to engineer the electronic properties of catalysts to improve their performance in CO 2 electrochemical reduction. Herein, we developed an efficient strategy to facilitate CO 2 activation by introducing oxygen vacancies into electrocatalysts with electronic‐rich surface. ZnO nanosheets rich in oxygen vacancies exhibited a current density of −16.1 mA cm −2 with a Faradaic efficiency of 83 % for CO production. Based on density functional theory (DFT) calculations, the introduction of oxygen vacancies increased the charge density of ZnO around the valence band maximum, resulting in the enhanced activation of CO 2 . Mechanistic studies further revealed that the enhancement of CO production by introducing oxygen vacancies into ZnO nanosheets originated from the increased binding strength of CO 2 and the eased CO 2 activation.

Hollow porous CoFe(2)O(4) nanocubes from metal-organic frameworks were fabricated through a general facile strategy. The intrinsic hollow nanostructure can shorten the lengths for both electronic and ionic transport, enlarge the surface area of electrodes, and improve accommodation of the volume change during Li insertion/extraction cycling. The hybrid multi-elements characteristics allow the volume change to take place in a stepwise manner during the electrochemical cycle. Therefore, the as-prepared CoFe(2)O(4) electrode exhibits outstanding performance as anode materials for lithium ion batteries. The stable capacity arrives at 815 mA h g(-1) for 20 C. Subsequently, a specific capacity of ca. 1043 mA h g(-1) is recovered when the current rate reduces back to 1 C after 200 cycles. This general strategy may shed light on a new avenue for large-scale synthesis of hollow porous hybrid nanocubes via MOFs for energy storage, environmental remediation and other novel applications.