Photo-assisted electrochemical strategy has garnered interest for its ability to diminish the large overpotential of lithium-oxygen batteries (LOBs). Nonetheless, creating a sophisticated photocatalyst capable of absorbing a wide spectrum of light and dramatically lowering the recombination rate for electron-hole pairs presents a significant challenge. Herein, we design an Ag-doped ZnO (Ag@ZnO) hollow nanosphere as photocatalysts to boost the reaction dynamics of photo-assisted LOBs. The Ag@ZnO hollow nanospheres, featuring a mesoporous structure, are beneficial for improving O2 transport and enabling the retention of discharge products. Additionally, the ability to absorb light and the efficiencies of electron-hole separation are enhanced for Ag@ZnO as a result of Ag doping. The electrons generated by photoexcitation facilitate the conversion of O2 to produce Li2O2 during discharge, whereas during charging, the presence of holes causes the decomposition of Li2O2. Consequently, a significantly low overpotential of 0.22 V, ultrahigh cycling efficiency of 93.73%, and good reversibility was achieved for the photo-assisted LOBs using Ag@ZnO. We consider that this work can offer a reliable strategy to improve electrochemical kinetics and contribute to the development of efficient photocatalysts for photo-assisted LOBs.

The adsorption and activation of N2 as well as the competitive hydrogen evolution reaction (HER) pose significant challenges to the electrocatalytic nitrogen reduction reaction (ENRR), which severely limits its industrial application. Therefore, exploring the ENRR electrocatalysts with high activity and selectivity is an extremely important task. In this work, the oxygen vacancy-rich Fe2O3/Co3O4 heterostructures (referred to as Vo-X-Fe2O3/ Co3O4) were rationally designed by employing Co3O4 as a template via a simple hydrothermal and subsequent calcination method, which acted as highly efficient ENRR electrocatalysts. The electrocatalytic activity of Vo-XFe2O3/Co3O4 can be easily regulated by optimization of the Fe content and the introduction of oxygen vacancy (Vo). The results demonstrate that the optimized Vo-1.0-Fe2O3/Co3O4 catalyst achieves a high NH3 yield of 47.37 mu g h- 1 mgcat-1 and a Faradaic efficiency (FE) of 22.42 %. Moreover, the excellent stability and reproducibility are also demonstrated. The comprehensive characterizations reveal that the exceptional performance of Vo-1.0-Fe2O3/Co3O4 can be attributed to the improved N2 adsorption and activation, restricted competitive HER and promoted electron transfer kinetics induced by the synergistic introduction of Vo and Fe. This work emerged a new speculating orientation for rational design of ENRR catalysts.

The electrocatalytic nitrogen reduction reaction (NRR) is a highly promising process for synthesizing ammonia and holds great potential to replace the traditional Haber-Bosch process. Here, we report a novel flower-shaped ZnS/CoS composite electrocatalyst for the NRR. Remarkably, the ZnS/CoS-105 heterojunction catalyst achieved an NH3 yield rate of 20.42 mu g h(-1) mg(cat.)(-1) and a faradaic efficiency (FE) of 11.83% at -0.45 V VS. RHE in an aqueous 0.1 M Na2SO4 solution. In addition, ZnS/CoS-105 showed remarkable stability (up to 24 h) for the NRR process.

The precise stoichiometry and lattice ordering of perovskite transition metal oxide (TMO) thin films enable the atomic-level catalytic mechanisms in the process of oxygen evolution reaction (OER), accordingly facilitating the creation and refinement potentially effective catalysts. Nevertheless, the fundamental understanding of the interaction between the electronic and structural properties of infinite-layer structured electrocatalysts, as well as their catalytic efficiency, remains lacking. Herein, the successful acquisition of the membranous LaNiO2 catalysts with infinite-layer phase were achieved via topological reconstruction. Subsequent electrochemical testing revealed a decrease in the OER performance of nickelate after reduction, attributed to the diminished bonding strength between catalyst and oxygen intermediates. Given these unexpected findings, this study aimed to leverage surface strains to manipulate electronic states, thereby modulating the OER performance of LaNiO2. Applying either compressive or tensile strains to LaNiO2 enabled the restoration of its performance to pre-reduction levels induced by hydrogen, owing to the reinforced bond strength between catalyst and oxygen intermediates. This research provides both experimental evidence and theoretical guidance for understanding the importance of defect and stress engineering in OER, offering valuable insights for improving OER performance in flexible nano-membranous electrocatalysts with infinite-layer phase for practical applications.

LiBr as a promising redox mediator (RM) has been applied in Li-O2 batteries to improve oxygen evolution reaction kinetics and reduce overpotentials. However, the redox shuttle of Br3− can induce the unexpected reactions and thus cause the degradation of LiBr and the corrosion of Li anode, resulting in the poor cyclability and the low round-trip efficiency. Herein, MgBr2 is firstly employed with dual functions for Li-O2 batteries, which can serve as a RM and a SEI film-forming agent. The Br– is beneficial to facilitating the decomposition of Li2O2 and thus decreasing the overpotential. Additionally, a uniform SEI film containing Mg and MgO generates on Li anode surface by the in-situ spontaneous reactions of Mg2+ and Li anode in an O2 environment, which can suppress the redox shuttle of Br3− and improve the interface stability of Li anode and electrolyte. Benefiting from these advantages, the cycle life of Li-O2 battery with MgBr2 electrolyte is significantly extended.

Photo-assisted lithium-oxygen (Li-O 2 ) batteries have been developed as a new system to reduce a large overpotential in the Li-O 2 batteries.However, constructing an optimized photocatalyst is still a challenge to achieve broad light absorption and a low recombined rate of photoexcited electrons and holes.Herein, oxygen vacancy-rich molybdenum trioxide (MoO 3-x ) nanorods are employed as photocatalysts to accelerate kinetics of cathode reactions in the photo-assisted Li-O 2 batteries.Oxygen vacancies on the MoO 3-x nanorods can not only increase light-harvesting capability but also improve electrochemical activity for the cathode reactions.Under illumination, the photoexcited electrons and holes are effectively separated on the MoO 3-x nanorods.During discharging, activated O 2 is reduced to Li 2 O 2 by the photoexcited electrons from the MoO 3-x nanorods.The photoexcited holes can promote the decomposition of Li 2 O 2 during subsequent charging.Accordingly, the photo-assisted Li-O 2 batteries with the MoO 3-x nanorods deliver an ultralow overpotential of 0.22 V, considerable rate capability, and good reversibility.We think that this work could give a reference for the exploitation and application of the photocatalysts in the photo-assisted Li-O 2 batteries.

The photo-assisted lithium-oxygen (Li-O-2) cell is widely concerned due to its low overpotential. However, rapid recombination rate of photogenerated electrons and holes remains a fundamental challenge for photo-assisted Li O-2 cells. Herein, we design an optical and magnetic fields co-assisted Li-O-2 cell based on a-Fe2O3 nanospindles. We employed PL spectrum and I-t curve confirm that under the magnetic field, the photogenerated electrons and holes are driven via the opposite Lorentz forces in photo-assisted Li-O-2 cells, which is beneficial to accelerating the formation and decomposition of Li2O2. The optical and magnetic fields co-assisted Li-O-2 cell based on a-Fe2O3 nanospindles achieves an ultra-high discharge platform of 3.47 V and a low charge platform of 3.57 V, as well as a surprising energy efficiency of 97.2%. In addition, the optical and magnetic fields co-assisted Li-O-2 cell can stably cycle for over 25 cycles. This study offers a reference for improving the electrochemical kinetics of photo-assisted Li-O-2 cell by introducing magnetic field, which opens up a new avenue for the development of high-performance Li-O-2 cells.

Li metal is considered as an ideal anode for Li-O2 batteries because of its unbeatably theoretical specific capacity and low electrode potential. Unfortunately, the growth of Li dendritic and the sensitivity to electrolyte and O2 hinder the practical applications of Li anode. Herein, AlF3 as an electrolyte additive is firstly employed in a Li-O2 battery, which can boost the formation of LiF@Al-Li@Al2O3-rich SEI film via in-situ spontaneous reactions of AlF3 with Li anode in O2 atmosphere. The generated SEI film contributes to inducing the homogeneous nucleation of Li and reducing the disgusting side reactions, which can suppress the growth of Li dendrite and improve the cyclability of Li anode. Benefiting from the rational design, both the Li-O2 and the Li|Li symmetric batteries with AlF3 electrolyte exhibit low overpotential and good cycling stability. We hope this work could provide a facile way to in-situ construct a stable SEI film to alleviate the uneven Li nucleation for Li-O2 batteries.